This is Google's cache of
Google's cache is the snapshot that we took of the page as we crawled the web.
The page may have changed since that time. Click here for the current page without highlighting.

Google is not affiliated with the authors of this page nor responsible for its content.

Provided by The Internet Classics Archive.
See bottom for copyright. Available online at

On the Natural Faculties
By Galen

Translated by Arthur John Brock



1. Since feeling and voluntary motion are peculiar to animals, whilst
growth and nutrition are common to plants as well, we may look on
the former as effects of the soul and the latter as effects of the
nature. And if there be anyone who allows a share in soul to plants
as well, and separates the two kinds of soul, naming the kind in question
vegetative, and the other sensory, this person is not saying anything
else, although his language is somewhat unusual. We, however, for
our part, are convinced that the chief merit of language is clearness,
and we know that nothing detracts so much from this as do unfamiliar
terms; accordingly we employ those terms which the bulk of people
are accustomed to use, and we say that animals are governed at once
by their soul and by their nature, and plants by their nature alone,
and that growth and nutrition are the effects of nature, not of soul.

2. Thus we shall enquire, in the course of this treatise, from what
faculties these effects themselves, as well as any other effects of
nature which there may be, take their origin. 

First, however, we must distinguish and explain clearly the various
terms which we are going to use in this treatise, and to what things
we apply them; and this will prove to be not merely an explanation
of terms but at the same time a demonstration of the effects of nature.

When, therefore, such and such a body undergoes no change from its
existing state, we say that it is at rest; but, not withstanding,
if it departs from this in any respect we then say that in this respect
it undergoes motion. Accordingly, when it departs in various ways
from its preexisting state, it will be said to undergo various kinds
of motion. Thus, if that which is white becomes black, or what is
black becomes white, it undergoes motion in respect to colour; or
if what was previously sweet now becomes bitter, or, conversely, from
being bitter now becomes sweet, it will be said to undergo motion
in respect to flavour; to both of these instances, as well as to those
previously mentioned, we shall apply the term qualitative motion.
And further, it is not only things which are altered in regard to
colour and flavour which, we say, undergo motion; when a warm thing
becomes cold, and a cold warm, here too we speak of its undergoing
motion; similarly also when anything moist becomes dry, or dry moist.
Now, the common term which we apply to all these cases is alteration.

This is one kind of motion. But there is another kind which occurs
in bodies which change their position, or as we say, pass from one
place to another; the name of this is transference. 

These two kinds of motion, then, are simple and primary, while compounded
from them we have growth and decay, as when a small thing becomes
bigger, or a big thing smaller, each retaining at the same time its
particular form. And two other kinds of motion are genesis and destruction,
genesis being a coming into existence, and destruction being the opposite.

Now, common to all kinds of motion is change from the preexisting
state, while common to all conditions of rest is retention of the
preexisting state. The Sophists, however, while allowing that bread
in turning into blood becomes changed as regards sight, taste, and
touch, will not agree that this change occurs in reality. Thus some
of them hold that all such phenomena are tricks and illusions of our
senses; the senses, they say, are affected now in one way, now in
another, whereas the underlying substance does not admit of any of
these changes to which the names are given. Others (such as Anaxagoras)
will have it that the qualities do exist in it, but that they are
unchangeable and immutable from eternity to eternity, and that these
apparent alterations are brought about by separation and combination.

Now, if I were to go out of my way to confute these people, my subsidiary
task would be greater than my main one. Thus, if they do not know
all that has been written, "On Complete Alteration of Substance" by
Aristotle, and after him by Chrysippus, I must beg of them to make
themselves familiar with these men's writings. If, however, they know
these, and yet willingly prefer the worse views to the better, they
will doubtless consider my arguments foolish also. I have shown elsewhere
that these opinions were shared by Hippocrates, who lived much earlier
than Aristotle. In fact, all those known to us who have been both
physicians and philosophers Hippocrates was the first who took in
hand to demonstrate that there are, in all, four mutually interacting
qualities, and that to the operation of these is due the genesis and
destruction of all things that come into and pass out of being. Nay,
more; Hippocrates was also the first to recognise that all these qualities
undergo an intimate mingling with one another; and at least the beginnings
of the proofs to which Aristotle later set his hand are to be found
first in the writings of Hippocrates. 

As to whether we are to suppose that the substances as well as their
qualities undergo this intimate mingling, as Zeno of Citium afterwards
declared, I do not think it necessary to go further into this question
in the present treatise; for immediate purposes we only need to recognize
the complete alteration of substance. In this way, nobody will suppose
that bread represents a kind of meeting-place for bone, flesh, nerve,
and all the other parts, and that each of these subsequently becomes
separated in the body and goes to join its own kind; before any separation
takes place, the whole of the bread obviously becomes blood; (at any
rate, if a man takes no other food for a prolonged period, he will
have blood enclosed in his veins all the same). And clearly this disproves
the view of those who consider the elements unchangeable, as also,
for that matter, does the oil which is entirely used up in the flame
of the lamp, or the faggots which, in a somewhat longer time, turn
into fire. 

I said, however, that I was not going to enter into an argument with
these people, and it was only because the example was drawn from the
subject-matter of medicine, and because I need it for the present
treatise, that I have mentioned it. We shall then, as I said, renounce
our controversy with them, since those who wish may get a good grasp
of the views of the ancients from our own personal investigations
into these matters. 

The discussion which follows we shall devote entirely, as we originally
proposed, to an enquiry into the number and character of the faculties
of Nature, and what is the effect which each naturally produces. Now,
of course, I mean by an effect that which has already come into existence
and has been completed by the activity of these faculties- for example,
blood, flesh, or nerve. And activity is the name I give to the active
change or motion, and the cause of this I call a faculty. Thus, when
food turns into blood, the motion of the food is passive, and that
of the vein active. Similarly, when the limbs have their position
their position altered, it is the muscle which produces, and the bones
which undergo the motion. In these cases I call the motion of the
vein and of the muscle an activity, and that of the food and the bones
a symptom or affection, since the first group undergoes alteration
and the second group is merely transported. One might, therefore,
also speak of the activity as an effect of Nature- for example, digestion,
absorption, blood-production; one could not, however, in every case
call the effect an activity; thus flesh is an effect of Nature, but
it is, of course, not an activity. It is, therefore, clear that one
of these terms is used in two senses, but not the other.

3. It appears to me, then, that the vein, as well as each of the other
parts, functions in such and such a way according to the manner in
which the four qualities are mixed. There are, however, a considerable
number of not undistinguished men- philosophers and physicians- who
refer action to the Warm and the Cold, and who subordinate to these,
as passive, the Dry and the Moist; Aristotle, in fact, was the first
who attempted to bring back the causes of the various special activities
to these principles, and he was followed later by the Stoic school.
These latter, of course, could logically make active principles of
the Warm and Cold, since they refer the change of the elements themselves
into one another to certain diffusions and condensations. This does
not hold of Aristotle, however; seeing that he employed the four qualities
to explain the genesis of the elements, he ought properly to have
also referred the causes of all the special activities to these. How
is it that he uses the four qualities in his book "On Genesis and
Destruction," whilst in his "Meteorology," his "Problems," and many
other works he uses the uses the two only? Of course, if anyone were
to maintain that in the case of animals and plants the Warm and Cold
are more active, the Dry and Moist less so, he might perhaps have
even Hippocrates on his side; but if he were to say that this happens
in all cases, he would, I imagine, lack support, not merely from Hippocrates,
but even from Aristotle himself- if, at least, Aristotle chose to
remember what he himself taught us in his work "On Genesis and Destruction,"
not as a matter of simple statement, but with an accompanying demonstration.
I have, however, also investigated these questions, in so far as they
are of value to a physician, in my work "On Temperaments."

4. The so-called blood-making faculty in the veins, then, as well
as all the other faculties, fall within the category of relative concepts;
primarily because the faculty is the cause of the activity, but also,
accidentally, because it is the cause of the effect. But, if the cause
is relative to something- for it is the cause of what results from
it, and of nothing else- it is obvious that the faculty also falls
into the category of the relative; and so long as we are ignorant
of the true essence of the cause which is operating, we call it a
faculty. Thus we say that there exists in the veins a blood-making
faculty, as also a digestive faculty in the stomach, a pulsatile faculty
in the heart, and in each of the other parts a special faculty corresponding
to the function or activity of that part. If, therefore, we are to
investigate methodically the number and kinds of faculties, we must
begin with the effects; for each of these effects comes from a certain
activity, and each of these again is preceded by a cause.

5. The effects of Nature, then, while the animal is still being formed
in the womb, are all the different parts of its body; and after it
has been born, an effect in which all parts share is the progress
of each to its full size, and thereafter its maintenance of itself
as long as possible. 

The activities corresponding to the three effects mentioned are necessarily
three- one to each- namely, Genesis, Growth, and Nutrition. Genesis,
however, is not a simple activity of Nature, but is compounded of
alteration and of shaping. That is to say, in order that bone, nerve,
veins, and all other [tissues] may come into existence, the underlying
substance from which the animal springs must be altered; and in order
that the substance so altered may acquire its appropriate shape and
position, its cavities, outgrowths, attachments, and so forth, it
has to undergo a shaping or formative process. One would be justified
in calling this substance which undergoes alteration the material
of the animal, just as wood is the material of a ship, and wax of
an image. 

Growth is an increase and expansion in length, breadth, and thickness
of the solid parts of the animal (those which have been subjected
to the moulding or shaping process). Nutrition is an addition to these,
without expansion. 

6. Let us speak then, in the first place, of Genesis, which, as we
have said, results from alteration together with shaping.

The seed having been cast into the womb or into the earth (for there
is no difference), then, after a certain definite period, a great
number of parts become constituted in the substance which is being
generated; these differ as regards moisture, dryness, coldness and
warmth, and in all the other qualities which naturally derive therefrom.
These derivative qualities, you are acquainted with, if you have given
any sort of scientific consideration to the question of genesis and
destruction. For, first and foremost after the qualities mentioned
come the other so-called tangible distinctions, and after them those
which appeal to taste, smell, and sight. Now, tangible distinctions
are hardness and softness, viscosity, friability, lightness, heaviness,
density, rarity, smoothness, roughness, thickness and thinness; all
of these have been duly mentioned by Aristotle. And of course you
know those which appeal to taste, smell, and sight. Therefore, if
you wish to know which alterative faculties are primary and elementary,
they are moisture, dryness, coldness, and warmth, and if you wish
to know which ones arise from the combination of these, they will
be found to be in each animal of a number corresponding to its sensible
elements. The name sensible elements is given to all the homogeneous
parts of the body, and these are to be detected not by any system,
but by personal observation of dissections. 

Now Nature constructs bone, cartilage, nerve, membrane, ligament,
vein, and so forth, at the first stage of the animal's genesis, employing
at this task a faculty which is, in general terms, generative and
alterative, and, in more detail, warming, chilling, drying, or moistening;
or such as spring from the blending of these, for example, the bone-producing,
nerve-producing, and cartilage-producing faculties (since for the
sake of clearness these names must be used as well). 

Now the peculiar flesh of the liver is of this kind as well, also
that of the spleen, that of the kidneys, that of the lungs, and that
of the heart; so also the proper substance of the brain, stomach,
gullet, intestines, and uterus is a sensible element, of similar parts
all through, simple, and uncompounded. That is to say, if you remove
from each of the organs mentioned its arteries, veins, and nerves,
the substance remaining in each organ is, from the point of view of
the senses, simple and elementary. As regards those organs consisting
of two dissimilar coats, of which each is simple, of these organs
the coats are the are the elements- for example, the coats of the
stomach, oesophagus, intestines, and arteries; each of these two coats
has an alterative faculty peculiar to it, which has engendered it
from the menstrual blood of the mother. Thus the special alterative
faculties in each animal are of the same number as the elementary
parts; and further, the activities must necessarily correspond each
to one of the special parts, just as each part has its special use-
for example, those ducts which extend from the kidneys into the bladder,
and which are called ureters; for these are not arteries, since they
do not pulsate nor do they consist of two coats; and they are not
veins, since they neither contain blood, nor do their coats in any
way resemble those of veins; from nerves they differ still more than
from the structures mentioned. 

"What, then, are they?" someone asks- as though every part must necessarily
be either an artery, a vein, a nerve, or a complex of these, and as
though the truth were not what I am now stating, namely, that every
one of the various organs has its own particular substance. For in
fact the two bladders- that which receives the urine, and that which
receives the yellow bile- not only differ from all other organs, but
also from one another. Further, the ducts which spring out like kinds
of conduits from the gall-bladder and which pass into the liver have
no resemblance either to arteries, veins or nerves. But these parts
have been treated at a greater length in my work "On the Anatomy of
Hippocrates," as well as elsewhere. 

As for the actual substance of the coats of the stomach, intestine,
and uterus, each of these has been rendered what it is by a special
alterative faculty of Nature; while the bringing of these together,
the therewith of the structures which are inserted into them, the
outgrowth into the intestine, the shape of the inner cavities, and
the like, have all been determined by a faculty which we call the
shaping or formative faculty; this faculty we also state to be artistic-
nay, the best and highest art- doing everything for some purpose,
so that there is nothing ineffective or superfluous, or capable of
being better disposed. This, however, I shall demonstrate in my work
"On the Use of Parts." 

7. Passing now to the faculty of Growth let us first mention that
this, too, is present in the foetus in utero as is also the nutritive
faculty, but that at that stage these two faculties are, as it were,
handmaids to those already mentioned, and do not possess in themselves
supreme authority. When, however, the animal has attained its complete
size, then, during the whole period following its birth and until
the acme is reached, the faculty of growth is predominant, while the
alterative and nutritive faculties are accessory- in fact, act as
its handmaids. What, then, is the property of this faculty of growth?
To extend in every direction that which has already come into existence-
that is to say, the solid parts of the body, the arteries, veins,
nerves, bones, cartilages, membranes, ligaments, and the various coats
which we have just called elementary, homogeneous, and simple. And
I shall state in what way they gain this extension in every direction,
first giving an illustration for the sake of clearness. 

Children take the bladders of pigs, fill them with air, and then rub
them on ashes near the fire, so as to warm, but not to injure them.
This is a common game in the district of Ionia, and among not a few
other nations. As they rub, they sing songs, to a certain measure,
time, and rhythm, and all their words are an exhortation to the bladder
to increase in size. When it appears to them fairly well distended,
they again blow air into it and expand it further; then they rub it
again. This they do several times, until the bladder seems to them
to have become large enough. Now, clearly, in these doings of the
children, the more the interior cavity of the bladder increases in
size, the thinner, necessarily, does its substance become. But, if
the children were able to bring nourishment to this thin part, then
they would make the bladder big in the same way that Nature does.
As it is, however, they cannot do what Nature does, for to imitate
this is beyond the power not only of children, but of any one soever;
it is a property of Nature alone. 

It will now, therefore, be clear to you that nutrition is a necessity
for growing things. For if such bodies were distended, but not at
the same time nourished, they would take on a false appearance of
growth, not a true growth. And further, to be distended in all directions
belongs only to bodies whose growth is directed by Nature; for those
which are distended by us undergo this distension in one direction
but grow less in the others; it is impossible to find a body which
will remain entire and not be torn through whilst we stretch it in
the three dimensions. Thus Nature alone has the power to expand a
body in all directions so that it remains unruptured and preserves
completely its previous form. 

Such then is growth, and it cannot occur without the nutriment which
flows to the part and is worked up into it. 

8. We have, then, it seems, arrived at the subject of Nutrition, which
is the third and remaining consideration which we proposed at the
outset. For, when the matter which flows to each part of the body
in the form of nutriment is being worked up into it, this activity
is nutrition, and its cause is the nutritive faculty. Of course, the
kind of activity here involved is also an alteration, but not an alteration
like that occurring at the stage of genesis. For in the latter case
something comes into existence which did not exist previously, while
in nutrition the inflowing material becomes assimilated to that which
has already come into existence. Therefore, the former kind of alteration
has with reason been termed genesis, and the latter, assimilation.

9. Now, since the three faculties of Nature have been exhaustively
dealt with, and the animal would appear not to need any others (being
possessed of the means for growing, for attaining completion, and
for maintaining itself as long a time as possible), this treatise
might seem to be already complete, and to constitute an exposition
of all the faculties of Nature. If, however, one considers that it
has not yet touched upon any of the parts of the animal (I mean the
stomach, intestines, liver, and the like), and that it has not dealt
with the faculties resident in these, it will seem as though merely
a kind of introduction had been given to the practical parts of our
teaching. For the whole matter is as follows: Genesis, growth, and
nutrition are the first, and, so to say, the principal effects of
Nature; similarly also the faculties which produce these effects-
the first faculties- are three in number, and are the most dominating
of all. But as has already been shown, these need the service both
of each other, and of yet different faculties. Now, these which the
faculties of generation and growth require have been stated. I shall
now say what ones the nutritive faculty requires. 

10. For I believe that I shall prove that the organs which have to
do with the disposal of the nutriment, as also their faculties, exist
for the sake of this nutritive faculty. For since the action of this
faculty is assimilation, and it is impossible for anything to be assimilated
by, and to change into anything else unless they already possess a
certain community and affinity in their qualities, therefore, in the
first place, any animal cannot naturally derive nourishment from any
kind of food, and secondly, even in the case of those from which it
can do so, it cannot do this at once. Therefore, by reason of this
law, every animal needs several organs for altering the nutriment.
For in order that the yellow may become red, and the red yellow, one
simple process of alteration is required, but in order that the white
may become black, and the black white, all the intermediate stages
are needed. So also, a thing which is very soft cannot all at once
become very hard, nor vice versa; nor, similarly can anything which
has a very bad smell suddenly become quite fragrant, nor again, can
the converse happen. 

How, then, could blood ever turn into bone, without having first become,
as far as possible, thickened and white? And how could bread turn
into blood without having gradually parted with its whiteness and
gradually acquired redness? Thus it is quite easy for blood to become
flesh; for, if Nature thicken it to such an extent that it acquires
a certain consistency and ceases to be fluid, it thus becomes original
newly-formed flesh; but in order that blood may turn into bone, much
time is needed and much elaboration and transformation of the blood.
Further, it is quite clear that bread, and, more particularly lettuce,
beet, and the like, require a great deal of alteration, in order to
become blood. 

This, then, is one reason why there are so many organs concerned in
the alteration of food. A second reason is the nature of the superfluities.
For, as we are unable to draw any nourishment from grass, although
this is possible for cattle, similarly we can derive nourishment from
radishes, albeit not to the same extent as from meat; for almost the
whole of the latter is mastered by our natures; it is transformed
and altered and constituted useful blood; but, not withstanding, in
the radish, what is appropriate and capable of being altered (and
that only with difficulty, and with much labour) is the very smallest
part; almost the whole of it is surplus matter, and passes through
the digestive organs, only a very little being taken up into the veins
as blood- nor is this itself entirely utilisable blood. Nature, therefore,
had need of a second process of separation for the superfluities in
the veins. Moreover, these superfluities need, on the one hand, certain
fresh routes to conduct them to the outlets, so that they may not
spoil the useful substances, and they also need certain reservoirs,
as it were, in which they are collected till they reach a sufficient
quantity, and are then discharged. 

Thus, then, you have discovered bodily parts of a second kind, consecrated
in this case to the [removal of the] superfluities of the food. There
is, however, also a third kind, for carrying the pabulum in every
direction; these are like a number of roads intersecting the whole

Thus there is one entrance- that through the mouth- for all the various
articles of food. What receives nourishment, however, is not one single
part, but a great many parts, and these widely separated; do not be
surprised, therefore, at the abundance of organs which Nature has
created for the purpose of nutrition. For those of them which have
to do with alteration prepare the nutriment suitable for each part;
others separate out the superfluities; some pass these along, others
store them up, others excrete them; some, again, are paths for the
transit in all directions of the utilisable juices. So, if you wish
to gain a thorough acquaintance with all the faculties of Nature,
you will have consider each one of these organs. 

Now in giving an account of these we must begin with those effects
of Nature, together with their corresponding parts and faculties,
which are closely connected with the purpose to be achieved.

11. Let us once more, then, recall the actual purpose for which Nature
has constructed all these parts. Its name, as previously stated, is
nutrition, and the definition corresponding to the name is: an assimilation
of that which nourishes to that which receives nourishment. And in
order that this may come about, we must assume a preliminary process
of adhesion, and for that, again, one of presentation. For whenever
the juice which is destined to nourish any of the parts of the animal
is emitted from the vessels, it is in the first place dispersed all
through this part, next it is presented, and next it adheres, and
becomes completely assimilated. 

The so-called white [leprosy] shows the difference between assimilation
and adhesion, in the same way that the kind of dropsy which some people
call anasarca clearly distinguishes presentation from adhesion. For,
of course, the genesis of such a dropsy does not come about as do
some of the conditions of atrophy and wasting, from an insufficient
supply of moisture; the flesh is obviously moist enough,- in fact
it is thoroughly saturated,- and each of the solid parts of the body
is in a similar condition. While, however, the nutriment conveyed
to the part does undergo presentation, it is still too watery, and
is not properly transformed into a juice, nor has it acquired that
viscous and agglutinative quality which results from the operation
of innate heat; therefore, adhesion cannot come about, since, owing
to this abundance of thin, crude liquid, the pabulum runs off and
easily slips away from the solid parts of the body. In white [leprosy],
again, there is adhesion of the nutriment but no real assimilation.
From this it is clear that what I have just said is correct, namely,
that in that part which is to be nourished there must first occur
presentation, next adhesion, and finally assimilation proper.

Strictly speaking, then, nutriment is that which is actually nourishing,
while the quasi-nutriment which is not yet nourishing (e.g. matter
which is undergoing adhesion or presentation) is not, strictly speaking,
nutriment, but is so called only by an equivocation. Also, that which
is still contained in the veins, and still more, that which is in
the stomach, from the fact that it is destined to nourish if properly
elaborated, has been called "nutriment." Similarly we call the various
kinds of food "nutriment," not because they are already nourishing
the animal, nor because they exist in the same state as the material
which actually is nourishing it, but because they are able and destined
to nourish it if they be properly elaborated. 

This was also what Hippocrates said, viz., "Nutriment is what is engaged
in nourishing, as also is quasi-nutriment, and what is destined to
be nutriment." For to that which is already being assimilated he gave
the name of nutriment; to the similar material which is being presented
or becoming adherent, the name of quasi-nutriment; and to everything
else- that is, contained in the stomach and veins- the name of destined

12. It is quite clear, therefore, that nutrition must necessarily
be a process of assimilation of that which is nourishing to that which
is being nourished. Some, however, say that this assimilation does
not occur in reality, but is merely apparent; these are the people
who think that Nature is not artistic, that she does not show forethought
for the animal's welfare, and that she has absolutely no native powers
whereby she alters some substances, attracts others, and discharges

Now, speaking generally, there have arisen the following two sects
in medicine and philosophy among those who have made any definite
pronouncement regarding Nature. I speak, of course, of such of them
as know what they are talking about, and who realize the logical sequence
of their hypotheses, and stand by them; as for those who cannot understand
even this, but who simply talk any nonsense that comes to their tongues,
and who do not remain definitely attached either to one sect or the
other- such people are not even worth mentioning. 

What, then, are these sects, and what are the logical consequences
of their hypotheses? The one class supposes that all substance which
is subject to genesis and destruction is at once continuous and susceptible
of alteration. The other school assumes substance to be unchangeable,
unalterable, and subdivided into fine particles, which are separated
from one another by empty spaces. 

All people, therefore, who can appreciate the logical sequence of
an hypothesis hold that, according to the second teaching, there does
not exist any substance or faculty peculiar either to Nature or to
Soul, but that these result from the way in which the primary corpuscles,
which are unaffected by change, come together. According to the first-mentioned
teaching, on the other hand, Nature is not posterior to the corpuscles,
but is a long way prior to them and older than they; and therefore
in their view it is Nature which puts together the bodies both of
plants and animals; and this she does by virtue of certain faculties
which she possesses- these being, on the one hand, attractive and
assimilative of what is appropriate, and, on the other, of what is
foreign. Further, she skilfully moulds everything during the stage
of genesis; and she also provides for the creatures after birth, employing
here other faculties again, namely, one of affection and forethought
for offspring, and one of sociability and friendship for kindred.
According to the other school, none of these things exist in the natures
[of living things], nor is there in the soul any original innate idea,
whether of agreement or difference, of separation or synthesis, of
justice or injustice, of the beautiful or ugly; all such things, they
say, arise in us from sensation and through sensation, and animals
are steered by certain images and memories. 

Some of these people have even expressly declared that the soul possesses
no reasoning faculty, but that we are led like cattle by the impression
of our senses, and are unable to refuse or dissent from anything.
In their view, obviously, courage, wisdom, temperance, and self-control
are all mere nonsense, we do not love either each other or our offspring,
nor do the gods care anything for us. This school also despises dreams,
birds, omens, and the whole of astrology, subjects with which we have
dealt at greater length in another work, in which we discuss the views
of Asclepiades the physician. Those who wish to do so may familiarize
themselves with these arguments, and they may also consider at this
point which of the two roads lying before us is the better one to
take. Hippocrates took the first-mentioned. According to this teaching,
substance is one and is subject to alteration; there is a consensus
in the movements of air and fluid throughout the whole body; Nature
acts throughout in an artistic and equitable manner, having certain
faculties, by virtue of which each part of the body draws to itself
the juice which is proper to it, and, having done so, attaches it
to every portion of itself, and completely assimilates it; while such
part of the juice as has not been mastered, and is not capable of
undergoing complete alteration and being assimilated to the part which
is being nourished, is got rid of by yet another (an expulsive) faculty.

13. Now the extent of exactitude and truth in the doctrines of Hippocrates
may be gauged, not merely from the way in which his opponents are
at variance with obvious facts, but also from the various subjects
of natural research themselves- the functions of animals, and the
rest. For those people who do not believe that there exists in any
part of the animal a faculty for attracting its own special quality
are compelled repeatedly to deny obvious facts. For instance, Asclepiades,
the physician, did this in the case of the kidneys. That these are
organs for secreting [separating out] the urine, was the belief not
only of Hippocrates, Diocles, Erasistratus, Praxagoras, and all other
physicians of eminence, but practically every butcher is aware of
this, from the fact that he daily observes both the position of the
kidneys and the duct (termed the ureter) which runs from each kidney
into the bladder, and from this arrangement he infers their characteristic
use and faculty. But, even leaving the butchers aside, all people
who suffer either from frequent dysuria or from retention of urine
call themselves "nephritics," when they feel pain in the loins and
pass sandy matter in their water. 

I do not suppose that Asclepiades ever saw a stone which had been
passed by one of these sufferers, or observed that this was preceded
by a sharp pain in the region between kidneys and bladder as the stone
traversed the ureter, or that, when the stone was passed, both the
pain and the retention at once ceased. It is worth while, then, learning
how his theory accounts for the presence of urine in the bladder,
and one is forced to marvel at the ingenuity of a man who puts aside
these broad, clearly visible routes, and postulates others which are
narrow, invisible- indeed, entirely imperceptible. His view, in fact,
is that the fluid which we drink passes into the bladder by being
resolved into vapours, and that, when these have been again condensed,
it thus regains its previous form, and turns from vapour into fluid.
He simply looks upon the bladder as a sponge or a piece of wool, and
not as the perfectly compact and impervious body that it is, with
two very strong coats. For if we say that the vapours pass through
these coats, why should they not pass through the peritoneum and the
diaphragm, thus filling the whole abdominal cavity and thorax with
water? "But," says he, "of course the peritoneal coat is more impervious
than the bladder, and this is why it keeps out the vapours, while
the bladder admits them." Yet if he had ever practised anatomy, he
might have known that the outer coat of the bladder springs from the
peritoneum and is essentially the same as it, and that the inner coat,
which is peculiar to the bladder, is more than twice as thick as the

Perhaps, however, it is not the thickness or thinness of the coats,
but the situation of the bladder, which is the reason for the vapours
being carried into it? On the contrary, even if it were probable for
every other reason that the vapours accumulate there, yet the situation
of the bladder would be enough in itself to prevent this. For the
bladder is situated below, whereas vapours have a natural tendency
to rise upwards; thus they would fill all the region of the thorax
and lungs long before they came to the bladder. 

But why do I mention the situation of the bladder, peritoneum, and
thorax? For surely, when the vapours have passed through the coats
of the stomach and intestines, it is in the space between these and
the peritoneum that they will collect and become liquefied (just as
in dropsical subjects it is in this region that most of the water
gathers). Otherwise the vapours must necessarily pass straight forward
through everything which in any way comes in contact with them, and
will never come to a standstill. But, if this be assumed, then they
will traverse not merely the peritoneum but also the epigastrium,
and will become dispersed into the surrounding air; otherwise they
will certainly collect under the skin. 

Even these considerations, however, our present-day Asclepiadeans
attempt to answer, despite the fact that they always get soundly laughed
at by all who happen to be present at their disputations on these
subjects- so difficult an evil to get rid of is this sectarian partizanship,
so excessively resistant to all cleansing processes, harder to heal
than any itch! 

Thus, one of our Sophists who is a thoroughly hardened disputer and
as skilful a master of language as there ever was, once got into a
discussion with me on this subject; so far from being put out of countenance
by any of the above-mentioned considerations, he even expressed his
surprise that I should try to overturn obvious facts by ridiculous
arguments! "For," said he, "one may clearly observe any day in the
case of any bladder, that, if one fills it with water or air and then
ties up its neck and squeezes it all round, it does not let anything
out at any point, but accurately retains all its contents. And surely,"
said he, "if there were any large and perceptible channels coming
into it from the kidneys the liquid would run out through these when
the bladder was squeezed, in the same way that it entered?" Having
abruptly made these and similar remarks in precise and clear tones,
he concluded by jumping up and departing- leaving me as though I were
quite incapable of finding any plausible answer! 

The fact is that those who are enslaved to their sects are not merely
devoid of all sound knowledge, but they will not even stop to learn!
Instead of listening, as they ought, to the reason why liquid can
enter the bladder through the ureters, but is unable to go back again
the same way,- instead of admiring Nature's artistic skill- they refuse
to learn; they even go so far as to scoff, and maintain that the kidneys,
as well as many other things, have been made by Nature for no purpose!
And some of them who had allowed themselves to be shown the ureters
coming from the kidneys and becoming implanted in the bladder, even
had the audacity to say that these also existed for no purpose; and
others said that they were spermatic ducts, and that this was why
they were inserted into the neck of the bladder and not into its cavity.
When, therefore, we had demonstrated to them the real spermatic ducts
entering the neck of the bladder lower down than the ureters, we supposed
that, if we had not done so before, we would now at least draw them
away from their false assumptions, and convert them forthwith to the
opposite view. But even this they presumed to dispute, and said that
it was not to be wondered at that the semen should remain longer in
these latter ducts, these being more constricted, and that it should
flow quickly down the ducts which came from the kidneys, seeing that
these were well dilated. We were, therefore, further compelled to
show them in a still living animal, the urine plainly running out
through the ureters into the bladder; even thus we hardly hoped to
check their nonsensical talk. 

Now the method of demonstration is as follows. One has to divide the
peritoneum in front of the ureters, then secure these with ligatures,
and next, having bandaged up the animal, let him go (for he will not
continue to urinate). After this one loosens the external bandages
and shows the bladder empty and the ureters quite full and distended-
in fact almost on the point of rupturing; on removing the ligature
from them, one then plainly sees the bladder becoming filled with

When this has been made quite clear, then, before the animal urinates,
one has to tie a ligature round his penis and then to squeeze the
bladder all over; still nothing goes back through the ureters to the
kidneys. Here, then, it becomes obvious that not only in a dead animal,
but in one which is still living, the ureters are prevented from receiving
back the urine from the bladder. These observations having been made,
one now loosens the ligature from the animal's penis and allows him
to urinate, then again ligatures one of the ureters and leaves the
other to discharge into the bladder. Allowing, then, some time to
elapse, one now demonstrates that the ureter which was ligatured is
obviously full and distended on the side next to the kidneys, while
the other one- that from which the ligature had been taken- is itself
flaccid, but has filled the bladder with urine. Then, again, one must
divide the full ureter, and demonstrate how the urine spurts out of
it, like blood in the operation of vene-section; and after this one
cuts through the other also, and both being thus divided, one bandages
up the animal externally. Then when enough time seems to have elapsed,
one takes off the bandages; the bladder will now be found empty, and
the whole region between the intestines and the peritoneum full of
urine, as if the animal were suffering from dropsy. Now, if anyone
will but test this for himself on an animal, I think he will strongly
condemn the rashness of Asclepiades, and if he also learns the reason
why nothing regurgitates from the bladder into the ureters, I think
he will be persuaded by this also of the forethought and art shown
by Nature in relation to animals. 

Now Hippocrates, who was the first known to us of all those who have
been both physicians and philosophers in as much as he was the first
to recognize what Nature effects, expresses his admiration of her,
and is constantly singing her praises and calling her "just." Alone,
he says, she suffices for the animal in every respect, performing
of her own accord and without any teaching all that is required. Being
such, she has, as he supposes, certain faculties, one attractive of
what is appropriate, and another eliminative of what is foreign, and
she nourishes the animal, makes it grow, and expels its diseases by
crisis. Therefore he says that there is in our bodies a concordance
in the movements of air and fluid, and that everything is in sympathy.
According to Asclepiades, however, nothing is naturally in sympathy
with anything else, all substance being divided and broken up into
inharmonious elements and absurd "molecules." Necessarily, then, besides
making countless other statements in opposition to plain fact, he
was ignorant of Nature's faculties, both that attracting what is appropriate,
and that expelling what is foreign. Thus he invented some wretched
nonsense to explain blood-production and anadosis, and, being utterly
unable to find anything to say regarding the clearing-out of superfluities,
he did not hesitate to join issue with obvious facts, and, in this
matter of urinary secretion, to deprive both the kidneys and the ureters
of their activity, by assuming that there were certain invisible channels
opening into the bladder. It was, of course, a grand and impressive
thing to do, to mistrust the obvious, and to pin one's faith in things
which could not be seen! 

Also, in the matter of the yellow bile, he makes an even grander and
more spirited venture; for he says this is actually generated in the
bile-ducts, not merely separated out. 

How comes it, then, that in cases of jaundice two things happen at
the same time- that the dejections contain absolutely no bile, and
that the whole body becomes full of it? He is forced here again to
talk nonsense, just as he did in regard to the urine. He also talks
no less nonsense about the black bile and the spleen, not understanding
what was said by Hippocrates; and he attempts in stupid- I might say
insane- language, to contradict what he knows nothing about.

And what profit did he derive from these opinions from the point of
view of treatment? He neither was able to cure a kidney ailment, nor
jaundice, nor a disease of black bile, nor would he agree with the
view held not merely by Hippocrates but by all men regarding drugs-
that some of them purge away yellow bile, and others black, some again
phlegm, and others the thin and watery superfluity; he held that all
the substances evacuated were produced by the drugs themselves, just
as yellow bile is produced by the biliary passages! It matters nothing,
according to this extraordinary man, whether we give a hydragogue
or a cholagogue in a case of dropsy, for these all equally purge and
dissolve the body, and produce a solution having such and such an
appearance, which did not exist as such before! 

Must we not, therefore, suppose he was either mad, or entirely unacquainted
with practical medicine? For who does not know that if a drug for
attracting phlegm be given in a case of jaundice it will not even
evacuate four cyathi of phlegm? Similarly also if one of the hydragogues
be given. A cholagogue, on the other hand, clears away a great quantity
of bile, and the skin of patients so treated at once becomes clear.
I myself have, in many cases, after treating the liver condition,
then removed the disease by means of a single purgation; whereas,
if one had employed a drug for removing phlegm one would have done
no good. 

Nor is Hippocrates the only one who knows this to be so, whilst those
who take experience alone as their starting-point know otherwise;
they, as well as all physicians who are engaged in the practice of
medicine, are of this opinion. Asclepiades, however, is an exception;
he would hold it a betrayal of his assumed "elements" to confess the
truth about such matters. For if a single drug were to be discovered
which attracted such and such a humour only, there would obviously
be danger of the opinion gaining ground that there is in every body
a faculty which attracts its own particular quality. He therefore
says that safflower, the Cnidian berry, and Hippophaes, do not draw
phlegm from the body, but actually make it. Moreover, he holds that
the flower and scales of bronze, and burnt bronze itself, and germander,
and wild mastich dissolve the body into water, and that dropsical
patients derive benefit from these substances, not because they are
purged by them, but because they are rid of substances which actually
help to increase the disease; for, if the medicine does not evacuate
the dropsical fluid contained in the body, but generates it, it aggravates
the condition further. Moreover, scammony, according to the Asclepiadean
argument, not only fails to evacuate the bile from the bodies of jaundiced
subjects, but actually turns the useful blood into bile, and dissolves
the body; in fact it does all manner of evil and increases the disease.

And yet this drug may be clearly seen to do good to numbers of people!
"Yes," says he, "they derive benefit certainly, but merely in proportion
to the evacuation."... But if you give these cases a drug which draws
off phlegm they will not be benefited. This is so obvious that even
those who make experience alone their starting-point are aware of
it; and these people make it a cardinal point of their teaching to
trust to no arguments, but only to what can be clearly seen. In this,
then, they show good sense; whereas Asclepiades goes far astray in
bidding us distrust our senses where obvious facts plainly overturn
his hypotheses. Much better would it have been for him not to assail
obvious facts, but rather to devote himself entirely to these.

Is it, then, these facts only which are plainly irreconcilable with
the views of Asclepiades? Is not also the fact that in summer yellow
bile is evacuated in greater quantity by the same drugs, and in winter
phlegm, and that in a young man more bile is evacuated, and in an
old man more phlegm? Obviously each drug attracts something which
already exists, and does not generate something previously non-existent.
Thus if you give in the summer season a drug which attracts phlegm
to a young man of a lean and warm habit, who has lived neither idly
nor too luxuriously, you will with great difficulty evacuate a very
small quantity of this humour, and you will do the man the utmost
harm. On the other hand, if you give him a cholagogue, you will produce
an abundant evacuation and not injure him at all. 

Do we still, then, disbelieve that each drug attracts that humour
which is proper to it? Possibly the adherents of Asclepiades will
assent to this- or rather, they will- not possibly, but certainly-
declare that they disbelieve it, lest they should betray their darling

14. Let us pass on, then, again to another piece of nonsense; for
the sophists do not allow one to engage in enquiries that are of any
worth, albeit there are many such; they compel one to spend one's
time in dissipating the fallacious arguments which they bring forward.

What, then, is this piece of nonsense? It has to do with the famous
and far-renowned stone which draws iron [the lodestone]. It might
be thought that this would draw their minds to a belief that there
are in all bodies certain faculties by which they attract their own
proper qualities. 

Now Epicurus, despite the fact that he employs in his "Physics" elements
similar to those of Asclepiades, yet allows that iron is attracted
by the lodestone, and chaff by amber. He even tries to give the cause
of the phenomenon. His view is that the atoms which flow from the
stone are related in shape to those flowing from the iron, and so
they become easily interlocked with one another; thus it is that,
after colliding with each of the two compact masses (the stone and
the iron) they then rebound into the middle and so become entangled
with each other, and draw the iron after them. So far, then, as his
hypotheses regarding causation go, he is perfectly unconvincing; nevertheless,
he does grant that there is an attraction. Further, he says that it
is on similar principles that there occur in the bodies of animals
the dispersal of nutriment and the discharge of waste matters, as
also the actions of cathartic drugs. 

Asclepiades, however, who viewed with suspicion the incredible character
of the cause mentioned, and who saw no other credible cause on the
basis of his supposed elements, shamelessly had recourse to the statement
that nothing is in any way attracted by anything else. Now, if he
was dissatisfied with what Epicurus said, and had nothing better to
say himself, he ought to have refrained from making hypotheses, and
should have said that Nature is a constructive artist and that the
substance of things is always tending towards unity and also towards
alteration because its own parts act upon and are acted upon by one
another. For, if he had assumed this, it would not have been difficult
to allow that this constructive Nature has powers which attract appropriate
and expel alien matter. For in no other way could she be constructive,
preservative of the animal, and eliminative of its diseases, unless
it be allowed that she conserves what is appropriate and discharges
what is foreign. 

But in this matter, too, Asclepiades realized the logical sequence
of the principles he had assumed; he showed no scruples, however,
in opposing plain fact; he joins issue in this matter also, not merely
with all physicians, but with everyone else, and maintains that there
is no such thing as a crisis, or critical day, and that Nature does
absolutely nothing for the preservation of the animal. For his constant
aim is to follow out logical consequences and to upset obvious fact,
in this respect being opposed to Epicurus; for the latter always stated
the observed fact, although he gives an ineffective explanation of
it. For, that these small corpuscles belonging to the lodestone rebound,
and become entangled with other similar particles of the iron, and
that then, by means of this entanglement (which cannot be seen anywhere)
such a heavy substance as iron is attracted- I fail to understand
how anybody could believe this. Even if we admit this, the same principle
will not explain the fact that, when the iron has another piece brought
in contact with it, this becomes attached to it. 

For what are we to say? That, forsooth, some of the particles that
flow from the lodestone collide with the iron and then rebound back,
and that it is by these that the iron becomes suspended? that others
penetrate into it, and rapidly pass through it by way of its empty
channels? that these then collide with the second piece of iron and
are not able to penetrate it although they penetrated the first piece?
and that they then course back to the first piece, and produce entanglements
like the former ones? 

The hypothesis here becomes clearly refuted by its absurdity. As a
matter of fact, I have seen five writing-stylets of iron attached
to one another in a line, only the first one being in contact with
the lodestone, and the power being transmitted through it to the others.
Moreover, it cannot be said that if you bring a second stylet into
contact with the lower end of the first, it becomes held, attached,
and suspended, whereas, if you apply it to any other part of the side
it does not become attached. For the power of the lodestone is distributed
in all directions; it merely needs to be in contact with the first
stylet at any point; from this stylet again the power flows, as quick
as a thought, all through the second, and from that again to the third.
Now, if you imagine a small lodestone hanging in a house, and in contact
with it all round a large number of pieces of iron, from them again
others, from these others, and so on,- all these pieces of iron must
surely become filled with the corpuscles which emanate from the stone;
therefore, this first little stone is likely to become dissipated
by disintegrating into these emanations. Further, even if there be
no iron in contact with it, it still disperses into the air, particularly
if this be also warm. 

"Yes," says Epicurus, "but these corpuscles must be looked on as exceedingly
small, so that some of them are a ten-thousandth part of the size
of the very smallest particles carried in the air." Then do you venture
to say that so great a weight of iron can be suspended by such small
bodies? If each of them is a ten-thousandth part as large as the dust
particles which are borne in the atmosphere, how big must we suppose
the hook-like extremities by which they interlock with each other
to be? For of course this is quite the smallest portion of the whole

Then, again, when a small body becomes entangled with another small
body, or when a body in motion becomes entangled with another also
in motion, they do not rebound at once. For, further, there will of
course be others which break in upon them from above, from below,
from front and rear, from right and left, and which shake and agitate
them and never let them rest. Moreover, we must perforce suppose that
each of these small bodies has a large number of these hook-like extremities.
For by one it attaches itself to its neighbours, by another- the topmost
one- to the lodestone, and by the bottom one to the iron. For if it
were attached to the stone above and not interlocked with the iron
below, this would be of no use. Thus, the upper part of the superior
extremity must hang from the lodestone, and the iron must be attached
to the lower end of the inferior extremity; and, since they interlock
with each other by their sides as well, they must, of course, have
hooks there too. Keep in mind also, above everything, what small bodies
these are which possess all these different kinds of outgrowths. Still
more, remember how, in order that the second piece of iron may become
attached to the first, the third to the second, and to that the fourth,
these absurd little particles must both penetrate the passages in
the first piece of iron and at the same time rebound from the piece
coming next in the series, although this second piece is naturally
in every way similar to the first. 

Such an hypothesis, once again, is certainly not lacking in audacity;
in fact, to tell the truth, it is far more shameless than the previous
ones; according to it, when five similar pieces of iron are arranged
in a line, the particles of the lodestone which easily traverse the
first piece of iron rebound from the second, and do not pass readily
through it in the same way. Indeed, it is nonsense, whichever alternative
is adopted. For, if they do rebound, how then do they pass through
into the third piece? And if they do not rebound, how does the second
piece become suspended to the first? For Epicurus himself looked on
the rebound as the active agent in attraction. 

But, as I have said, one is driven to talk nonsense whenever one gets
into discussion with such men. Having, therefore, given a concise
and summary statement of the matter, I wish to be done with it. For
if one diligently familiarizes oneself with the writings of Asclepiades,
one will see clearly their logical dependence on his first principles,
but also their disagreement with observed facts. Thus, Epicurus, in
his desire to adhere to the facts, cuts an awkward figure by aspiring
to show that these agree with his principles, whereas Asclepiades
safeguards the sequence of principles, but pays no attention to the
obvious fact. Whoever, therefore, wishes to expose the absurdity of
their hypotheses, must, if the argument be in answer to Asclepiades,
keep in mind his disagreement with observed fact; or if in answer
to Epicurus, his discordance with his principles. Almost all the other
sects depending on similar principles are now entirely extinct, while
these alone maintain a respectable existence still. Yet the tenets
of Asclepiades have been unanswerably confuted by Menodotus the Empiricist,
who draws his attention to their opposition to phenomena and to each
other; and, again, those of Epicurus have been confuted by Asclepiades,
who adhered always to logical sequence, about which Epicurus evidently
cares little. 

Now people of the present day do not begin by getting a clear comprehension
of these sects, as well as of the better ones, thereafter devoting
a long time to judging and testing the true and false in each of them;
despite their ignorance, they style themselves, some "physicians"
and others "philosophers." No wonder, then, that they honour the false
equally with the true. For everyone becomes like the first teacher
that he comes across, without waiting to learn anything from anybody
else. And there are some of them, who, even if they meet with more
than one teacher, are yet so unintelligent and slow-witted that even
by the time they have reached old age they are still incapable of
understanding the steps of an argument.... In the old days such people
used to be set to menial tasks.... What will be the end of it God

Now, we usually refrain from arguing with people whose principles
are wrong from the outset. Still, having been compelled by the natural
course of events to enter into some kind of a discussion with them,
we must add this further to what was said- that it is not only cathartic
drugs which naturally attract their special qualities, but also those
which remove thorns and the points of arrows such as sometimes become
deeply embedded in the flesh. Those drugs also which draw out animal
poisons or poisons applied to arrows all show the same faculty as
does the lodestone. Thus, I myself have seen a thorn which was embedded
in a young man's foot fail to come out when we exerted forcible traction
with our fingers, and yet come away painlessly and rapidly on the
application of a medicament. Yet even to this some people will object,
asserting that when the inflammation is dispersed from the part the
thorn comes away of itself, without being pulled out by anything.
But these people seem, in the first place, to be unaware that there
are certain drugs for drawing out inflammation and different ones
for drawing out embedded substances; and surely if it was on the cessation
of an inflammation that the abnormal matters were expelled, then all
drugs which disperse inflammations ought ipso facto; to possess the
power of extracting these substances as well. 

And secondly, these people seem to be unaware of a still more surprising
fact, namely, that not merely do certain medicaments draw out thorns
and others poisons, but that of the latter there are some which attract
the poison of the viper, others that of the sting-ray, and others
that of some other animal; we can, in fact, plainly observe these
poisons deposited on the medicaments. Here, then, we must praise Epicurus
for the respect he shows towards obvious facts, but find fault with
his views as to causation. For how can it be otherwise than extremely
foolish to suppose that a thorn which we failed to remove by digital
traction could be drawn out by these minute particles? 

Have we now, therefore, convinced ourselves that everything which
exists possesses a faculty by which it attracts its proper quality,
and that some things do this more, and some less? 

Or shall we also furnish our argument with the illustration afforded
by corn? For those who refuse to admit that anything is attracted
by anything else, will, I imagine, be here proved more ignorant regarding
Nature than the very peasants. When, for my own part, I first learned
of what happens, I was surprised, and felt anxious to see it with
my own eyes. Afterwards, when experience also had confirmed its truth,
I sought long among the various sects for an explanation, and, with
the exception of that which gave the first place to attraction, I
could find none which even approached plausibility, all the others
being ridiculous and obviously quite untenable. 

What happens, then, is the following. When our peasants are bringing
corn from the country into the city in wagons, and wish to filch some
away without being detected, they fill earthen jars with water and
stand them among the corn; the corn then draws the moisture into itself
through the jar and acquires additional bulk and weight, but the fact
is never detected by the onlookers unless someone who knew about the
trick before makes a more careful inspection. Yet, if you care to
set down the same vessel in the very hot sun, you will find the daily
loss to be very little indeed. Thus corn has a greater power than
extreme solar heat of drawing to itself the moisture in its neighbourhood.
Thus the theory that the water is carried towards the rarefied part
of the air surrounding us (particularly when that is distinctly warm)
is utter nonsense; for although it is much more rarefied there than
it is amongst the corn, yet it does not take up a tenth part of the
moisture which the corn does. 

15. Since, then, we have talked sufficient nonsense- not willingly,
but because we were forced, as the proverb says, "to behave madly
among madmen"- let us return again to the subject of urinary secretion.
Here let us forget the absurdities of Asclepiades, and, in company
with those who are persuaded that the urine does pass through the
kidneys, let us consider what is the character of this function. For,
most assuredly, either the urine is conveyed by its own motion to
the kidneys, considering this the better course (as do we when we
go off to market!), or, if this be impossible, then some other reason
for its conveyance must be found. What, then, is this? If we are not
going to grant the kidneys a faculty for attracting this particular
quality, as Hippocrates held, we shall discover no other reason. For,
surely everyone sees that either the kidneys must attract the urine,
or the veins must propel it- if, that is, it does not move of itself.
But if the veins did exert a propulsive action when they contract,
they would squeeze out into the kidneys not merely the urine, but
along with it the whole of the blood which they contain. And if this
is impossible, as we shall show, the remaining explanation is that
the kidneys do exert traction. 

And how is propulsion by the veins impossible? The situation of the
kidneys is against it. They do not occupy a position beneath the hollow
vein [vena cava] as does the sieve-like [ethmoid] passage in the nose
and palate in relation to the surplus matter from the brain; they
are situated on both sides of it. Besides, if the kidneys are like
sieves, and readily let the thinner serous [whey-like] portion through,
and keep out the thicker portion, then the whole of the blood contained
in the vena cava must go to them, just as the whole of the wine is
thrown into the filters. Further, the example of milk being made into
cheese will show clearly what I mean. For this, too, although it is
all thrown into the wicker strainers, does not all percolate through;
such part of it as is too fine in proportion to the width of the meshes
passes downwards, and this is called whey [serum]; the remaining thick
portion which is destined to become cheese cannot get down, since
the pores of the strainers will not admit it. Thus it is that, if
the blood-serum has similarly to percolate through the kidneys, the
whole of the blood must come to them, and not merely one part of it.

What, then, is the appearance as found on dissection? 
One division of the vena cava is carried upwards to the heart, and
the other mounts upon the spine and extends along its whole length
as far as the legs; thus one division does not even come near the
kidneys, while the other approaches them but is certainly not inserted
into them. Now, if the blood were destined to be purified by them
as if they were sieves, the whole of it would have to fall into them,
the thin part being and the thick part retained above. But, as a matter
of fact, this is not so. For the kidneys lie on either side of the
vena cava. They therefore do not act like sieves, filtering fluid
sent to them by the vena cava, and themselves contributing no force.
They obviously exert traction; for this is the only remaining alternative.

How, then, do they exert this traction? If, as Epicurus thinks, all
attraction takes place by virtue of the rebounds and entanglements
of atoms, it would be certainly better to maintain that the kidneys
have no attractive action at all; for his theory, when examined, would
be found as it stands to be much more ridiculous even than the theory
of the lodestone, mentioned a little while ago. Attraction occurs
in the way that Hippocrates laid down; this will be stated more clearly
as the discussion proceeds; for the present our task is not to demonstrate
this, but to point out that no other cause of the secretion of urine
can be given except that of attraction by the kidneys, and that this
attraction does not take place in the way imagined by people who do
not allow Nature a faculty of her own. 

For if it be granted that there is any attractive faculty at all in
those things which are governed by Nature, a person who attempted
to say anything else about the absorption of nutriment would be considered
a fool. 

16. Now, while Erasistratus for some reason replied at great length
to certain other foolish doctrines, he entirely passed over the view
held by Hippocrates, not even thinking it worth while to mention it,
as he did in his work "On Deglutition"; in that work, as may be seen,
he did go so far as at least to make mention of the word attraction,
writing somewhat as follows: 

"Now, the stomach does not appear to exercise any attraction." But
when he is dealing with anadosis he does not mention the Hippocratic
view even to the extent of a single syllable. Yet we should have been
satisfied if he had even merely written this: "Hippocrates lies in
saying 'The flesh attracts both from the stomach and from without,'
for it cannot attract either from the stomach or from without." Or
if he had thought it worth while to state that Hippocrates was wrong
in criticizing the weakness of the neck of the uterus, "seeing that
the orifice of the uterus has no power of attracting semen," or if
he [Erasistratus] had thought proper to write any other similar opinion,
then we in our turn would have defended ourselves in the following

"My good sir, do not run us down in this rhetorical fashion without
some proof; state some definite objection to our view, in order that
either you may convince us by a brilliant refutation of the ancient
doctrine, or that, on the other hand, we may convert you from your
ignorance." Yet why do I say "rhetorical"? For we too are not to suppose
that when certain rhetoricians pour ridicule upon that which they
are quite incapable of refuting, without any attempt at argument,
their words are really thereby constituted rhetoric. For rhetoric
proceeds by persuasive reasoning; words without reasoning are buffoonery
rather than rhetoric. Therefore, the reply of Erasistratus in his
treatise "On Deglutition" was neither rhetoric nor logic. For what
is it that he says? "Now, the stomach does not appear to exercise
any traction." Let us testify against him in return, and set our argument
beside his in the same form. Now, there appears to be no peristalsis
of the gullet. "And how does this appear?" one of his adherents may
perchance ask. "For is it not indicative of peristalsis that always
when the upper parts of the gullet contract the lower parts dilate?"
Again, then, we say, "And in what way does the attraction of the stomach
not appear? For is it not indicative of attraction that always when
the lower parts of the gullet dilate the upper parts contract?" Now,
if he would but be sensible and recognize that this phenomenon is
not more indicative of the one than of the other view, but that it
applies equally to both, we should then show him without further delay
the proper way to the discovery of truth. 

We will, however, speak about the stomach again. And the dispersal
of nutriment [anadosis] need not make us have recourse to the theory
regarding the natural tendency of a vacuum to become refilled, when
once we have granted the attractive faculty of the kidneys. Now, although
Erasistratus knew that this faculty most certainly existed, he neither
mentioned it nor denied it, nor did he make any statement as to his
views on the secretion of urine. 

Why did he give notice at the very beginning of his "General Principles"
that he was going to speak about natural activities- firstly what
they are, how they take place, and in what situations- and then, in
the case of urinary secretion, declared that this took place through
the kidneys, but left out its method of occurrence? It must, then,
have been for no purpose that he told us how digestion occurs, or
spends time upon the secretion of biliary superfluities; for in these
cases also it would have been sufficient to have named the parts through
which the function takes place, and to have omitted the method. On
the contrary, in these cases he was able to tell us not merely through
what organs, but also in what way it occurs- as he also did, I think,
in the case of anadosis; for he was not satisfied with saying that
this took place through the veins, but he also considered fully the
method, which he held to be from the tendency of a vacuum to become
refilled. Concerning the secretion of urine, however, he writes that
this occurs through the kidneys, but does not add in what way it occurs.
I do not think he could say that this was from the tendency of matter
to fill a vacuum, for, if this were so, nobody would have ever died
of retention of urine, since no more can flow into a vacuum than has
run out. For, if no other factor comes into operation save only this
tendency by which a vacuum becomes refilled, no more could ever flow
in than had been evacuated. Nor, could he suggest any other plausible
cause, such, for example, as the of nutriment by the stomach which
occurs in the process of anadosis; this had been entirely disproved
in the case of blood in the vena cava; it is excluded, not merely
owing to the long distance, but also from the fact that the overlying
heart, at each diastole, robs the vena cava by violence of a considerable
quantity of blood. 

In relation to the lower part of the vena cava there would still remain,
solitary and abandoned, the specious theory concerning the filling
of a vacuum. This, however, is deprived of plausibility by the fact
that people die of retention of urine, and also, no less, by the situation
of the kidneys. For, if the whole of the blood were carried to the
kidneys, one might properly maintain that it all undergoes purification
there. But, as a matter of fact, the whole of it does not go to them,
but only so much as can be contained in the veins going to the kidneys;
this portion only, therefore, will be purified. Further, the thin
serous part of this will pass through the kidneys as if through a
sieve, while the thick sanguineous portion remaining in the veins
will obstruct the blood flowing in from behind; this will first, therefore,
have to run back to the vena cava, and so to empty the veins going
to the kidneys; these veins will no longer be able to conduct a second
quantity of unpurified blood to the kidneys- occupied as they are
by the blood which had preceded, there is no passage left. What power
have we, then, which will draw back the purified blood from the kidneys?
And what power,in the next place, will bid this blood retire to the
lower part of the vena cava, and will enjoin on another quantity coming
from above not to proceed downwards before turning off into the kidneys?

Now Erasistratus realized that all these ideas were open to many objections,
and he could only find one idea which held good in all respects- namely,
that of attraction. Since, therefore, he did not wish either to get
into difficulties or to mention the view of Hippocrates, he deemed
it better to say nothing at all as to the manner in which secretion

But even if he kept silence, I am not going to do so. For I know that
if one passes over the Hippocratic view and makes some other pronouncement
about the function of the kidneys, one cannot fall to make oneself
utterly ridiculous. It was for this reason that Erasistratus kept
silence and Asclepiades lied; they are like slaves who have had plenty
to say in the early part of their career, and have managed by excessive
rascality to escape many and frequent accusations, but who, later,
when caught in the act of thieving, cannot find any excuse; the more
modest one then keeps silence, as though thunderstruck, whilst the
more shameless continues to hide the missing article beneath his arm
and denies on oath that he has ever seen it. For it was in this way
also that Asclepiades, when all subtle excuses had failed him and
there was no longer any room for nonsense about "conveyance towards
the rarefied part [of the air]," and when it was impossible without
incurring the greatest derision to say that this superfluity [i.e.
the urine] is generated by the kidneys as is bile by the canals in
the liver- he, then, I say, clearly lied when he swore that the urine
does not reach the kidneys, and maintained that it passes, in the
form of vapour, straight from the region of the vena cava, to collect
in the bladder. 

Like slaves, then, caught in the act of stealing, these two are quite
bewildered, and while the one says nothing, the other indulges in
shameless lying. 

17. Now such of the younger men as have dignified themselves with
the names of these two authorities by taking the appellations "Erasistrateans"
or "Asclepiadeans" are like the Davi and Getae- the slaves introduced
by the excellent Menander into his comedies. As these slaves held
that they had done nothing fine unless they had cheated their master
three times, so also the men I am discussing have taken their time
over the construction of impudent sophisms, the one party striving
to prevent the lies of Asclepiades from ever being refuted, and the
other saying stupidly what Erasistratus had the sense to keep silence

But enough about the Asclepiadeans. The Erasistrateans, in attempting
to say how the kidneys let the urine through, will do anything or
suffer anything or try any shift in order to find some plausible explanation
which does not demand the principle of attraction. 

Now those near the times of Erasistratus maintain that the parts above
the kidneys receive pure blood, whilst the watery residue, being heavy,
tends to run downwards; that this, after percolating through the kidneys
themselves, is thus rendered serviceable, and is sent, as blood, to
all the parts below the kidneys. 

For a certain period at least this view also found favour and flourished,
and was held to be true; after a time, however, it became suspect
to the Erasistrateans themselves, and at last they abandoned it. For
apparently the following two points were assumed, neither of which
is conceded by anyone, nor is even capable of being proved. The first
is the heaviness of the serous fluid, which was said to be produced
in the vena cava, and which did not exist, apparently, at the beginning,
when this fluid was being carried up from the stomach to the liver.
Why, then, did it not at once run downwards when it was in these situations?
And if the watery fluid is so heavy, what plausibility can anyone
find in the statement that it assists in the process of anadosis?

In the second place there is this absurdity, that even if it be agreed
that all the watery fluid does fall downwards, and only when it is
in the vena cava, still it is difficult, or, rather, impossible, to
say through what means it is going to fall into the kidneys, seeing
that these are not situated below, but on either side of the vena
cava, and that the vena cava is not inserted into them, but merely
sends a branch into each of them, as it also does into all the other

What doctrine, then, took the place of this one when it was condemned?
One which to me seems far more foolish than the first, although it
also flourished at one time. For they say, that if oil be mixed with
water and poured upon the ground, each will take a different route,
the one flowing this way and the other that, and that, therefore,
it is not surprising that the watery fluid runs into the kidneys,
while the blood falls downwards along the vena cava. Now this doctrine
also stands already condemned. For why, of the countless veins which
spring from the vena cava, should blood flow into all the others,
and the serous fluid be diverted to those going to the kidneys? They
have not answered the question which was asked; they merely state
what happens and imagine they have thereby assigned the reason.

Once again, then (the third cup to the Saviour!), let us now speak
of the worst doctrine of all, lately invented by Lycus of Macedonia,
but which is popular owing to its novelty. This Lycus, then, maintains,
as though uttering an oracle from the inner sanctuary, that urine
is residual matter from the nutrition of the kidneys! Now, the amount
of urine passed every day shows clearly that it is the whole of the
fluid drunk which becomes urine, except for that which comes away
with the dejections or passes off as sweat or insensible perspiration.
This is most easily recognized in winter in those who are doing no
work but are carousing, especially if the wine be thin and diffusible;
these people rapidly pass almost the same quantity as they drink.
And that even Erasistratus was aware of this is known to those who
have read the first book of his "General Principles." Thus Lycus is
speaking neither good Erasistratism, nor good Asclepiadism, far less
good Hippocratism. He is, therefore, as the saying is, like a white
crow, which cannot mix with the genuine crows owing to its colour,
nor with the pigeons owing to its size. For all this, however, he
is not to be disregarded; he may, perhaps, be stating some wonderful
truth, unknown to any of his predecessors. 

Now it is agreed that all parts which are undergoing nutrition produce
a certain amount of residue, but it is neither agreed nor is it likely,
that the kidneys alone, small bodies as they are, could hold four
whole congii, and sometimes even more, of residual matter. For this
surplus must necessarily be greater in quantity in each of the larger
viscera; thus, for example, that of the lung, if it corresponds in
amount to the size of the viscus, will obviously be many times more
than that in the kidneys, and thus the whole of the thorax will become
filled, and the animal will be at once suffocated. But if it be said
that the residual matter is equal in amount in each of the other parts,
where are the bladders, one may ask, through which it is excreted?
For, if the kidneys produce in drinkers three and sometimes four congii
of superfluous matter, that of each of the other viscera will be much
more, and thus an enormous barrel will be needed to contain the waste
products of them all. Yet one often urinates practically the same
quantity as one has drunk, which would show that the whole of what
one drinks goes to the kidneys. 

Thus the author of this third piece of trickery would appear to have
achieved nothing, but to have been at once detected, and there still
remains the original difficulty which was insoluble by Erasistratus
and by all others except Hippocrates. I dwell purposely on this topic,
knowing well that nobody else has anything to say about the function
of the kidneys, but that either we must prove more foolish than the
very butchers if we do not agree that the urine passes through the
kidneys; or, if one acknowledges this, that then one cannot possibly
give any other reason for the secretion than the principle of attraction.

Now, if the movement of urine does not depend on the tendency of a
vacuum to become refilled, it is clear that neither does that of the
blood nor that of the bile; or if that of these latter does so, then
so also does that of the former. For they must all be accomplished
in one and the same way, even according to Erasistratus himself.

This matter, however, will be discussed more fully in the book following



1. In the previous book we demonstrated that not only Erasistratus,
but also all others who would say anything to the purpose about urinary
secretion, must acknowledge that the kidneys possess some faculty
which attracts to them this particular quality existing in the urine.
Besides this we drew attention to the fact that the urine is not carried
through the kidneys into the bladder by one method, the blood into
parts of the animal by another, and the yellow bile separated out
on yet another principle. For when once there has been demonstrated
in any one organ, the drawing, or so-called epispastic faculty, there
is then no difficulty in transferring it to the rest. Certainly Nature
did not give a power such as this to the kidneys without giving it
also to the vessels which abstract the biliary fluid, nor did she
give it to the latter without also it to each of the other parts.
And, assuredly, if this is true, we must marvel that Erasistratus
should make statements concerning the delivery of nutriment from the
food-canal which are so false as to be detected even by Asclepiades.
Now, Erasistratus considers it absolutely certain that, if anything
flows from the veins, one of two things must happen: either a completely
empty space will result, or the contiguous quantum of fluid will run
in and take the place of that which has been evacuated. Asclepiades,
however, holds that not one of two, but one of three things must be
said to result in the emptied vessels: either there will be an entirely
empty space, or the contiguous portion will flow in, or the vessel
will contract. For whereas, in the case of reeds and tubes it is true
to say that, if these be submerged in water, and are emptied of the
air which they contain in their lumens, then either a completely empty
space will be left, or the contiguous portion will move onwards; in
the case of veins this no longer holds, since their coats can collapse
and so fall in upon the interior cavity. It may be seen, then, how
false this hypothesis- by Zeus, I cannot call it a demonstration!-
of Erasistratus is. 

And, from another point of view, even if it were true, it is superfluous,
if the stomach has the power of compressing the veins, as he himself
supposed, and the veins again of contracting upon their contents and
propelling them forwards. For, apart from other considerations, no
plethora would ever take place in the body, if delivery of nutriment
resulted merely from the tendency of a vacuum to become refilled.
Now, if the compression of the stomach becomes weaker the further
it goes, and cannot reach to an indefinite distance, and if, therefore,
there is need of some other mechanism to explain why the blood is
conveyed in all directions, then the principle of the refilling of
a vacuum may be looked on as a necessary addition; there will not,
however, be a plethora in any of the parts coming after the liver,
or, if there be, it will be in the region of the heart and lungs;
for the heart alone of the parts which come after the liver draws
the nutriment into its right ventricle, thereafter sending it through
the arterioid vein to the lungs (for Erasistratus himself will have
it that, owing to the membranous excrescences, no other parts save
the lungs receive nourishment from the heart). If, however, in order
to explain how plethora comes about, we suppose the force of compression
by the stomach to persist indefinitely, we have no further need of
the principle of the refilling of a vacuum, especially if we assume
contraction of the veins in addition- as is, again, agreeable to Erasistratus

2. Let me draw his attention, then, once again, even if he does not
wish it, to the kidneys, and let me state that these confute in the
very clearest manner such people as object to the principle of attraction.
Nobody has ever said anything plausible, nor, as we previously showed,
has anyone been able to discover, by any means, any other cause for
the secretion of urine; we necessarily appear mad if we maintain that
the urine passes into the kidneys in the form of vapour, and we certainly
cut a poor figure when we talk about the tendency of a vacuum to become
refilled; this idea is foolish in the case of blood, and impossible,
nay, perfectly nonsensical, in the case of the urine. 

This, then, is one blunder made by those who dissociate themselves
from the principle of attraction. Another is that which they make
about the secretion of yellow bile. For in this case, too, it is not
a fact that when the blood runs past the mouths [stomata] of the bile-ducts
there will be a thorough separation out [secretion] of biliary waste-matter.
"Well," say they, "let us suppose that it is not secreted but carried
with the blood all over the body." But, you sapient folk, Erasistratus
himself supposed that Nature took thought for the animals' future,
and was workmanlike in her method; and at the same time he maintained
that the biliary fluid was useless in every way for the animals. Now
these two things are incompatible. For how could Nature be still looked
on as exercising forethought for the animal when she allowed a noxious
humour such as this to be carried off and distributed with the blood?...

This, however, is a small matter. I shall again point out here the
greatest and most obvious error. For if the yellow bile adjusts itself
to the narrower vessels and stomata, and the blood to the wider ones,
for no other reason than that blood is thicker and bile thinner, and
that the stomata of the veins are wider and those of the bile-ducts
narrower, then it is clear that this watery and serous superfluity,
too, will run out into the bile-ducts quicker than does the bile,
exactly in proportion as it is thinner than the bile! How is it, then,
that it does not run out? "Because," it may be said, "urine is thicker
than bile!" This was what one of our Erasistrateans ventured to say,
herein clearly disregarding the evidence of his senses, although he
had trusted these in the case of the bile and blood. For, if it be
that we are to look on bile as thinner than blood because it runs
more, then, since the serous residue passes through fine linen or
lint or a or a sieve more easily even than does bile, by these tokens
bile must also be thicker than the watery fluid. For here, again,
there is no argument which will demonstrate that bile is thinner than
the serous superfluities. 

But when a man shamelessly goes on using circumlocutions, and never
acknowledges when he has had a fall, he is like the amateur wrestlers,
who, when they have been overthrown by the experts and are lying on
their backs on the ground, so far from recognizing their fall, actually
seize their victorious adversaries by the necks and prevent them from
getting away, thus supposing themselves to be the winners!

3. Thus, every hypothesis of channels as an explanation of natural
functioning is perfect nonsense. For, if there were not an inborn
faculty given by Nature to each one of the organs at the very beginning,
then animals could not continue to live even for a few days, far less
for the number of years which they actually do. For let us suppose
they were under no guardianship, lacking in creative ingenuity and
forethought; let us suppose they were steered only by material forces,
and not by any special faculties (the one attracting what is proper
to it, another rejecting what is foreign, and yet another causing
alteration and adhesion of the matter destined to nourish it); if
we suppose this, I am sure it would be ridiculous for us to discuss
natural, or, still more, psychical, activities- or, in fact, life
as a whole. 

For there is not a single animal which could live or endure for the
shortest time if, possessing within itself so many different parts,
it did not employ faculties which were attractive of what is appropriate,
eliminative of what is foreign, and alterative of what is destined
for nutrition. On the other hand, if we have these faculties, we no
longer need channels, little or big, resting on an unproven hypothesis,
for explaining the secretion of urine and bile, and the conception
of some favourable situation (in which point alone Erasistratus shows
some common sense, since he does regard all the parts of the body
as having been well and truly placed and shaped by Nature).

But let us suppose he remained true to his own statement that Nature
is "artistic"- this Nature which, at the beginning, well and truly
shaped and disposed all the parts of the animal, and, after carrying
out this function (for she left nothing undone), brought it forward
to the light of day, endowed with certain faculties necessary for
its very existence, and, thereafter, gradually increased it until
it reached its due size. If he argued consistently on this principle,
I fail to see how he can continue to refer natural functions to the
smallness or largeness of canals, or to any other similarly absurd
hypothesis. For this Nature which shapes and gradually adds to the
parts is most certainly extended throughout their whole substance.
Yes indeed, she shapes and nourishes and increases them through and
through, not on the outside only. For Praxiteles and Phidias and all
the other statuaries used merely to decorate their material on the
outside, in so far as they were able to touch it; but its inner parts
they left unembellished, unwrought, unaffected by art or forethought,
since they were unable to penetrate therein and to reach and handle
all portions of the material. It is not so, however, with Nature.
Every part of a bone she makes bone, every part of the flesh she makes
flesh, and so with fat and all the rest; there is no part which she
has not touched, elaborated, and embellished. Phidias, on the other
hand, could not turn wax into ivory and gold, nor yet gold into wax:
for each of these remains as it was at the commencement, and becomes
a perfect statue simply by being clothed externally in a form and
artificial shape. But Nature does not preserve the original character
of any kind of matter; if she did so, then all parts of the animal
would be blood- that blood, namely, which flows to the semen from
the impregnated female and which is, so to speak, like the statuary's
wax, a single uniform matter, subjected to the artificer. From this
blood there arises no part of the animal which is as red and moist
[as blood is], for bone, artery, vein, nerve, cartilage, fat, gland,
membrane, and marrow are not blood, though they arise from it.

I would then ask Erasistratus himself to inform me what the altering,
coagulating, and shaping agent is. He would doubtless say, "Either
Nature or the semen," meaning the same thing in both cases, but explaining
it by different devices. For that which was previously semen, when
it begins to procreate and to shape the animal, becomes, so to say,
a special nature. For in the same way that Phidias possessed the faculties
of his art even before touching his material, and then activated these
in connection with this material (for every faculty remains inoperative
in the absence of its proper material), so it is with the semen: its
faculties it possessed from the beginning, while its activities it
does not receive from its material, but it manifests them in connection

And, of course, if it were to be overwhelmed with a great quantity
of blood, it would perish, while if it were to be entirely deprived
of blood it would remain inoperative and would not turn into a nature.
Therefore, in order that it may not perish, but may become a nature
in place of semen, there must be an afflux to it of a little blood-
or, rather, one should not say a little, but a quantity commensurate
with that of the semen. What is it then that measures the quantity
of this afflux? What prevents more from coming? What ensures against
a deficiency? What is this third overseer of animal generation that
we are to look for, which will furnish the semen with a due amount
of blood? What would Erasistratus have said if he had been alive,
and had been asked this question? Obviously, the semen itself. This,
in fact, is the artificer analogous with Phidias, whilst the blood
corresponds to the statuary's wax. 

Now, it is not for the wax to discover for itself how much of it is
required; that is the business of Phidias. Accordingly the artificer
will draw to itself as much blood as it needs. Here, however, we must
pay attention and take care not unwittingly to credit the semen with
reason and intelligence; if we were to do this, we would be making
neither semen nor a nature, but an actual living animal. And if we
retain these two principles- that of proportionate attraction and
that of the non-participation of intelligence- we shall ascribe to
the semen a faculty for attracting blood similar to that possessed
by the lodestone for iron. Here, then, again, in the case of the semen,
as in so many previous instances, we have been compelled to acknowledge
some kind of attractive faculty. 

And what is the semen? Clearly the active principle of the animal,
the material principle being the menstrual blood. Next, seeing that
the active principle employs this faculty primarily, therefore, in
order that any one of the things fashioned by it may come into existence,
it [the principle] must necessarily be possessed of its own faculty.
How, then, was Erasistratus unaware of it, if the primary function
of the semen be to draw to itself a due proportion of blood? Now,
this fluid would be in due proportion if it were so thin and vaporous,
that, as soon as it was drawn like dew into every part of the semen,
it would everywhere cease to display its own particular character;
for so the semen will easily dominate and quickly assimilate it- in
fact, will use it as food. It will then, I imagine, draw to itself
a second and a third quantum, and thus by feeding it acquires for
itself considerable bulk and quantity. In fact, the alterative faculty
has now been discovered as well, although about this also has not
written a word. And, thirdly the shaping faculty will become evident,
by virtue of which the semen firstly surrounds itself with a thin
membrane like a kind of superficial condensation; this is what was
described by Hippocrates in the sixth-day birth, which, according
to his statement, fell from the singing-girl and resembled the pellicle
of an egg. And following this all the other stages will occur, such
as are described by him in his work "On the Child's Nature."

But if each of the parts formed were to remain as small as when it
first came into existence, of what use would that be? They have, then,
to grow. Now, how will they grow? By becoming extended in all directions
and at the same time receiving nourishment. And if you will recall
what I previously said about the bladder which the children blew up
and rubbed, you will also understand my meaning better as expressed
in what I am now about to say. 

Imagine the heart to be, at the beginning, so small as to differ in
no respect from a millet-seed, or, if you will, a bean; and consider
how otherwise it is to become large than by being extended in all
directions and acquiring nourishment throughout its whole substance,
in the way that, as I showed a short while ago, the semen is nourished.
But even this was unknown to Erasistratus- the man who sings the artistic
skill of Nature! He imagines that animals grow like webs, ropes, sacks,
or baskets, each of which has, woven on to its end or margin, other
material similar to that of which it was originally composed.

But this, most sapient sir, is not growth, but genesis! For a bag,
sack, garment, house, ship, or the like is said to be still coming
into existence [undergoing genesis] so long as the appropriate form
for the sake of which it is being constructed by the artificer is
still incomplete. Then, when does it grow? Only when the basket, being
complete, with a bottom, a mouth, and a belly, as it were, as well
as the intermediate parts, now becomes larger in all these respects.
"And how can this happen?" someone will ask. Only by our basket suddenly
becoming an animal or a plant; for growth belongs to living things
alone. Possibly you imagine that a house grows when it is being built,
or a basket when being plated, or a garment when being woven? It is
not so, however. Growth belongs to that which has already been completed
in respect to its form, whereas the process by which that which is
still becoming attains its form is termed not growth but genesis.
That which is, grows, while that which is not, becomes. 

4. This also was unknown to Erasistratus, whom nothing escaped, if his followers
speak in any way truly in maintaining that he was familiar with the Peripatetic
philosophers. Now, in so far as he acclaims Nature as being an artist in
construction, even I recognize the Peripatetic teachings, but in other respects
he does not come near them. For if anyone will make himself acquainted with the
writings of Aristotle and Theophrastus, these will appear to him to consist of
commentaries on the Nature-lore [physiology] of Hippocrates- according to which
the principles of heat, cold, dryness and moisture act upon and are acted upon
by one another, the hot principle being the most active, and the cold coming
next to it in power; all this was stated in the first place by Hippocrates and
secondly by Aristotle. Further, it is at once the Hippocratic and the
Aristotelian teaching that the parts which receive that nourishment throughout
their whole substance, and that, similarly, processes of mingling and
alteration involve the entire substance. Moreover, that digestion is a species
of alteration- a transmutation of the nutriment into the proper quality of the
thing receiving it; that blood-production also is an alteration, and nutrition
as well; that growth results from extension in all directions, combined with
nutrition; that alteration is effected mainly by the warm principle, and that
therefore digestion, nutrition, and the generation of the various humours, as
well as the qualities of the surplus substances, result from the innate heat;
all these and many other points besides in regard to the aforesaid faculties,
the origin of diseases, and the discovery of remedies, were correctly stated
first by Hippocrates of all writers whom we know, and were in the second place
correctly expounded by Aristotle. Now, if all these views meet with the
approval of the Peripatetics, as they undoubtedly do, and if none of them
satisfy Erasistratus, what can the Erasistrateans possibly mean by claiming
that their leader was associated with these philosophers? The fact is, they
revere him as a god, and think that everything he says is true. If this be so,
then we must suppose the Peripatetics to have strayed very far from truth,
since they approve of none of the ideas of Erasistratus. And, indeed, the
disciples of the latter produce his connection with the Peripatetics in order
to furnish his Nature-lore with a respectable pedigree.

Now, let us reverse our argument and put it in a different way from that which
we have just employed. For if the Peripatetics were correct in their teaching
about Nature, there could be nothing more absurd than the contentions of
Erasistratus. And, I will leave it to the Erasistrateans themselves to decide;
they must either advance the one proposition or the other. According to the
former one the Peripatetics had no accurate acquaintance with Nature, and
according to the second, Erasistratus. It is my task, then, to point out the
opposition between the two doctrines, and theirs to make the choice....

But they certainly will not abandon their reverence for Erasistratus. Very
well, then; let them stop talking about the Peripatetic philosophers. For among
the numerous physiological teachings regarding the genesis and destruction of
animals, their health, their diseases, and the methods of treating these, there
will be found one only which is common to Erasistratus and the Peripatetics-
namely, the view that Nature does everything for some purpose, and nothing in

But even as regards this doctrine their agreement is only verbal; in practice
Erasistratus makes havoc of it a thousand times over. For, according to him,
the spleen was made for no purpose, as also the omentum; similarly, too, the
arteries which are inserted into kidneys- although these are practically the
largest of all those that spring from the great artery [aorta]! And to judge by
the Erasistratean argument, there must be countless other useless structures;
for, if he knows nothing at all about these structures, he has little more
anatomical knowledge than a butcher, while, if he is acquainted with them and
yet does not state their use, he clearly imagines that they were made for no
purpose, like the spleen. Why, however, should I discuss these structures
fully, belonging as they do to the treatise "On the Use of Parts," which I am
personally about to complete?

Let us, then, sum up again this same argument, and, having said a few words
more in answer to the Erasistrateans, proceed to our next topic. The fact is,
these people seem to me to have read none of Aristotle's writings, but to have
heard from others how great an authority he was on "Nature," and that those of
the Porch follow in the steps of his Nature-lore; apparently they then
discovered a single one of the current ideas which is common to Aristotle and
Erasistratus, and made up some story of a connection between Erasistratus and
these people. That Erasistratus, however, has no share in the Nature-lore of
Aristotle is shown by an enumeration of the aforesaid doctrines, which emanated
first from Hippocrates, secondly from Aristotle, thirdly from the Stoics (with
a single modification, namely, that for them the qualities are bodies).
Perhaps, however, they will maintain that it was in the matter of logic that
Erasistratus associated himself with the Peripatetic philosophers? Here they
show ignorance of the fact that these philosophers never brought forward false
or inconclusive arguments, while the Erasistratean books are full of them.

So perhaps somebody may already be asking, in some surprise, what possessed
Erasistratus that he turned so completely from the doctrines of Hippocrates,
and why it is that he takes away the attractive faculty from the biliary
passages in the liver- for we have sufficiently discussed the kidneys- alleging
[as the cause of bile-secretion] a favourable situation, the narrowness of
vessels, and a common space into which the veins from the gateway [of the
liver] conduct the unpurified blood, and from which, in the first place, the
[biliary] passages take over the bile, and secondly, the [branches] of the vena
cava take over the purified blood. For it would not only have done him no harm
to have mentioned the idea of attraction, but he would thereby have been able
to get rid of countless other disputed questions.

5. At the actual moment, however, the Erasistrateans are engaged in a considerable
battle, not only with others but also amongst themselves, and so they cannot
explain the passage from the first book of the "General Principles," in which
Erasistratus says, "Since there are two kinds of vessels opening at the same
place, the one kind extending to the gall-bladder and the other to the vena
cava, the result is that, of the nutriment carried up from the alimentary
canal, that part which fits both kinds of stomata is received into both kinds
of vessels, some being carried into the gall-bladder, and the rest passing over
into the vena cava." For it is difficult to say what we are to understand by
the words "opening at the same place" which are written at the beginning of
this passage. Either they mean there is a junction between the termination of
the vein which is on the concave surface of the liver and two other vascular
terminations (that of the vessel on the convex surface of the liver and that of
the bile-duct), or, if not, then we must suppose that there is, as it were, a
common space for all three vessels, which becomes filled from the lower vein,
and empties itself both into the bile-duct and into the branches of the vena
cava. Now, there are many difficulties in both of these explanations, but if I
were to state them all, I should find myself inadvertently writing an
exposition of the teaching of Erasistratus, instead of carrying out my original
undertaking. There is, however, one difficulty common to both these
explanations, namely, that the whole of the blood does not become purified. For
it ought to fall into the bile-duct as into a kind of sieve, instead of going
(running, in fact, rapidly) past it, into the larger stoma, by virtue of the
impulse of anadosis.

Are these, then, the only inevitable difficulties in which the argument of
Erasistratus becomes involved through his disinclination to make any use of the
attractive faculty, or is it that the difficulty is greatest here, and also so
obvious that even a child could not avoid seeing it?

6. And if one looks carefully into the matter one will find that even
Erasistratus' reasoning on the subject of nutrition, which he takes up in the
second book of his "General Principles," fails to escape this same difficulty.
For, having conceded one premise to the principle that matter tends to fill a
vacuum, as we previously showed, he was only able to draw a conclusion in the
case of the veins and their contained blood. That is to say, when blood is
running away through the stomata of the veins, and is being dispersed, then,
since an absolutely empty space cannot result, and the veins cannot collapse
(for this was what he overlooked), it was therefore shown to be necessary that
the that the adjoining quantum of fluid should flow in and fill the place of
the fluid evacuated. It is in this way that we may suppose the veins to be
nourished; they get the benefit of the blood which they contain. But how about
the nerves? For they do not also contain blood. One might obviously say that
they draw their supply from the veins. But Erasistratus will not have it so.
What further contrivance, then, does he suppose? He says that a nerve has
within itself veins and arteries, like a rope woven by Nature out of three
different strands. By means of this hypothesis he imagined that his theory
would escape from the idea of attraction. For if the nerve contain within
itself a blood-vessel it will no longer need the adventitious flow of other
blood from the real vein lying adjacent; this fictitious vessel, perceptible
only in theory, will suffice it for nourishment.

But this, again, is succeeded by another similar difficulty. For this small
vessel will nourish itself, but it will not be able to nourish this adjacent
simple nerve or artery, unless these possess some innate proclivity for
attracting nutriment. For how could the nerve, being simple, attract its
nourishment, as do the composite veins, by virtue of the tendency of a vacuum
to become refilled? For, although according to Erasistratus, it contains within
itself a cavity of sorts, this is not occupied with blood, but with psychic
pneuma, and we are required to imagine the nutriment introduced, not into this
cavity, but into the vessel containing it, whether it needs merely to be
nourished, or to grow as well. How, then, are we to imagine it introduced? For
this simple vessel [i.e. nerve] is so small- as are also the other two- that if
you prick it at any part with the finest needle you will tear the whole three
of them at once. Thus there could never be in it a perceptible space entirely
empty. And an emptied space which merely existed in theory could not compel the
adjacent fluid to come and fill it.

At this point, again, I should like Erasistratus himself to answer regarding
this small elementary nerve, whether it is actually one and definitely
continuous, or whether it consists of many small bodies, such as those assumed
by Epicurus, Leucippus, and Democritus. For I see that the Erasistrateans are
at variance on this subject. Some of them consider it one and continuous, for
otherwise, as they say, he would not have called it simple; and some venture to
resolve it into yet other elementary bodies. But if it be one and continuous,
then what is evacuated from it in the so-called insensible transpiration of the
physicians will leave no empty space in it; otherwise it would not be one body
but many, separated by empty spaces. But if it consists of many bodies, then we
have "escaped by the back door," as the saying is, to Asclepiades, seeing that
we have postulated certain inharmonious elements. Once again, then, we must
call Nature "inartistic"; for this necessarily follows the assumption of such

For this reason some of the Erasistrateans seem to me to have done very
foolishly in reducing the simple vessels to elements such as these. Yet it
makes no difference to me, since the theory of both parties regarding nutrition
will be shown to be absurd. For in these minute simple vessels constituting the
large perceptible nerves, it is impossible, according to the theory of those
who would keep the former continuous, that any "refilling of a vacuum" should
take place, since no vacuum can occur in a continuum even if anything does run
away; for the parts left come together (as is seen in the case of water) and
again become one, taking up the whole space of that which previously separated
them. Nor will any "refilling" occur if we accept the argument of the other
Erasistrateans, since none of their elements need it. For this principle only
holds of things which are perceptible, and not of those which exist merely in
theory; this Erasistratus expressly acknowledges, for he states that it is not
a vacuum such as this, interspersed in small portions among the corpuscles,
that his various treatises deal with, but a vacuum which is clear, perceptible,
complete in itself, large in size, evident, or however else one cares to term
it (for, what Erasistratus himself says is, that "there cannot be a perceptible
space which is entirely empty"; while I, for my part, being abundantly equipped
with terms which are equally elucidatory, at least in relation to the present
topic of discussion, have added them as well).

Thus it seems to me better that we also should help the Erasistrateans with
some contribution, since we are on the subject, and should advise those who
reduce the vessel called primary and simple by Erasistratus into other
elementary bodies to give up their opinion; for not only do they gain nothing
by it, but they are also at variance with Erasistratus in this matter. That
they gain nothing by it has been clearly demonstrated; for this hypothesis
could not escape the difficulty regarding nutrition. And it also seems
perfectly evident to me that this hypothesis is not in consonance with the view
of Erasistratus, when it declares that what he calls simple and primary is
composite, and when it destroys the principle of Nature's artistic skill. For,
if we do not grant a certain unity of substance to these simple structures as
well, and if we arrive eventually at inharmonious and indivisible elements, we
shall most assuredly deprive Nature of her artistic skill, as do all the
physicians and philosophers who start from this hypothesis. For, according to
such a hypothesis, Nature does not precede, but is secondary to the parts of
the animal. Now, it is not the province of what comes secondarily, but of what
pre-exists, to shape and to construct. Thus we must necessarily suppose that
the faculties of Nature, by which she shapes the animal, and makes it grow and
receive nourishment, are present from the seed onwards; whereas none of these
inharmonious and non-partite corpuscles contains within itself any formative,
incremental, nutritive, or, in a word, any artistic power; it is, by
hypothesis, unimpressionable and untransformable, whereas, as we have
previously shown, none of the processes mentioned takes place without
transformation, alteration, and complete intermixture. And, owing to this
necessity, those who belong to these sects are unable to follow out the
consequences of their supposed elements, and they are all therefore forced to
declare Nature devoid of art. It is not from us, however, that the
Erasistrateans should have learnt this, but from those very philosophers who
lay most stress on a preliminary investigation into the elements of all
existing things.

Now, one can hardly be right in supposing that Erasistratus could reach such a
pitch of foolishness as to be recognizing the logical consequences of this
theory, and that, while assuming Nature to be artistically creative, he would
at the same time break up substance into insensible, inharmonious, and
untransformable elements. If, however, he will grant that there occurs in the
elements a process of alteration and transformation, and that there exists in
them unity and continuity, then that simple vessel of his (as he himself names
it) will turn out to be single and uncompounded. And the simple vein will
receive nourishment from itself, and the nerve and artery from the vein. How,
and in what way? For, when we were at this point before, we drew attention to
the disagreement among the Erasistrateans, and we showed that the nutrition of
these simple vessels was impraticable according to the teachings of both
parties, although we did not hesitate to adjudicate in their quarrel and to do
Erasistratus the honour of placing him in the better sect.

Let our argument, then, be transferred again to the doctrine which assumes this
elementary nerve to be a single, simple, and entirely unified structure, and
let us consider how it is to be nourished; for what is discovered here will at
once be found to be common also to the school of Hippocrates.

It seems to me that our enquiry can be most rigorously pursued in subjects who
are suffering from illness and have become very emaciated, since in these
people all parts of the body are obviously atrophied and thin, and in need of
additional substance and feeding-up; for the same reason the ordinary
perceptible nerve, regarding which we originally began this discussion, has
become thin, and requires nourishment. Now, this contains within itself various
parts, namely, a great many of these primary, invisible, minute nerves, a few
simple arteries, and similarly also veins. Thus, all its elementary nerves have
themselves also obviously become emaciated; for, if they had not, neither would
the nerve as a whole; and of course, in such a case, the whole nerve cannot
require nourishment without each of these requiring it too. Now, if on the one
hand they stand in need of feeding-up, and if on the other the principle of the
refilling of a vacuum can give them no help- both by reason of the difficulties
previously mentioned and the actual thinness, as I shall show- we must then
seek another cause for nutrition.

How is it, then, that the tendency of a vacuum to become refilled is unable to
afford nourishment to one in such a condition? Because its rule is that only so
much of the contiguous matter should succeed as has flowed away. Now this is
sufficient for nourishment in the case of those who are in good condition, for,
in them, what is presented must be equal to what has flowed away. But in the
case of those who are very emaciated and who need a great restoration of
nutrition, unless what was presented were many times greater than what has been
emptied out, they would never be able to regain their original habit. It is
clear, therefore, that these parts will have to exert a greater amount of
attraction, in so far as their requirements are greater. And I fail to
understand how Erasistratus does not perceive that here again he is putting the
cart before the horse. Because, in the case of the sick, there must be a large
amount of presentation in order to feed them up, he argues that the factor of
"refilling" must play an equally large part. And how could much presentation
take place if it were not preceded by an abundant delivery of nutriment? And if
he calls the conveyance of food through the veins delivery, and its assumption
by each of these simple and visible nerves and arteries not delivery but
distribution, as some people have thought fit to name it, and then ascribes
conveyance through the veins to the principle of vacuum refilling alone, let
him explain to us the assumption of food by the hypothetical elements. For it
has been shown that at least in relation to these there is no question of the
refilling of a vacuum being in operation, and especially where the parts are
very attenuated. It is worth while listening to what Erasistratus says about
these cases in the second book of his "General Principles": "In the ultimate
simple [vessels], which are thin and narrow, presentation takes place from the
adjacent vessels, the nutriment being attracted through the sides of the
vessels and deposited in the empty spaces left by the matter which has been
carried away." Now, in this statement firstly I admit and accept the words
"through the sides." For, if the simple nerve were actually to take in the food
through its mouth, it could not distribute it through its whole substance; for
the mouth is dedicated to the psychic pneuma. It can, however, take it in
through its sides from the adjacent simple vein. Secondly, I also accept in
Erasistratus' statement the expression which precedes "through the sides." What
does this say? "The nutriment being attracted through the sides of the
vessels." Now I, too, agree that it is attracted, but it has been previously
shown that this is not through the tendency of evacuated matter to be replaced.

7. Let us, then, consider together how it is attracted. How else than in the way
that iron is attracted by the lodestone, the latter having a faculty attractive
of this particular quality [existing in iron]? But if the beginning of anadosis
depends on the squeezing action of the stomach, and the whole movement
thereafter on the peristalsis and propulsive action of the veins, as well as on
the traction exerted by each of the parts which are undergoing nourishment,
then we can abandon the principle of replacement of evacuated matter, as not
being suitable for a man who assumes Nature to be a skilled artist; thus we
shall also have avoided the contradiction of Asclepiades though we cannot
refute it: for the disjunctive argument used for the purposes of demonstration
is, in reality, disjunctive not of two but of three alternatives; now, if we
treat the disjunction as a disjunction of two alternatives, one of the two
propositions assumed in constructing our proof must be false; and if as a
disjunctive of three alternatives, no conclusion will be arrived at.

8. Now Erasistratus ought not to have been ignorant of this if he had ever had
anything to do with the Peripatetics- even in a dream. Nor, similarly, should
he have been unacquainted with the genesis of the humours, about which, not
having even anything moderately plausible to say, he thinks to deceive us by
the excuse that the consideration of such matters is not the least useful.
Then, in Heaven's name, is it useful to know how food is digested in the
stomach, but unnecessary to know how bile comes into existence in the veins?
Are we to pay attention merely to the evacuation of this humour, and not to its
genesis? As though it were not far better to prevent its excessive development
from the beginning than to give ourselves all the trouble of expelling it! And
it is a strange thing to be entirely unaware as to whether its genesis is to be
looked on as taking place in the body, or whether it comes from without and is
contained in the food. For, if it was right to raise this problem, why should
we not make investigations concerning the blood as well- whether it takes its
origin in the body, or is distributed through the food as is maintained by
those who postulate homoeomeries? Assuredly it would be much more useful to
investigate what kinds of food are suited, and what kinds unsuited, to the
process of blood-production rather than to enquire into what articles of diet
are easily mastered by the activity of the stomach, and what resist and contend
with it. For the choice of the latter bears reference merely to digestion,
while that of the former is of importance in regard to the generation of useful
blood. For it is not equally important whether the aliment be imperfectly
chylified in the stomach or whether it fail to be turned into useful blood. Why
is Erasistratus not ashamed to distinguish all the various kinds of digestive
failure and all the occasions which give rise to them, whilst in reference to
the errors of blood-production he does not utter a single word- nay, not a
syllable? Now, there is certainly to be found in the veins both thick and thin
blood; in some people it is redder, in others yellower, in some blacker, in
others more of the nature of phlegm. And one who realizes that it may smell
offensively not in one way only, but in a great many different respects (which
cannot be put into words, although perfectly appreciable to the senses), would,
I imagine, condemn in no measured terms the carelessness of Erasistratus in
omitting a consideration so essential to the practice of our art.

Thus it is clear what errors in regard to the subject of dropsies logically
follow this carelessness. For, does it not show the most extreme carelessness
to suppose that the blood is prevented from going forward into the liver owing
to the narrowness of the passages, and that dropsy can never occur in any other
way? For, to imagine that dropsy is never caused by the spleen or any other
part, but always by induration of the liver, is the standpoint of a man whose
intelligence is perfectly torpid and who is quite out of touch with things that
happen every day. For, not merely once or twice, but frequently, we have
observed dropsy produced by chronic haemorrhoids which have been suppressed, or
which, through immoderate bleeding, have given the patient a severe chill;
similarly, in women, the complete disappearance of the monthly discharge, or an
undue evacuation such as is caused by violent bleeding from the womb, often
provoke dropsy; and in some of them the so-called female flux ends in this
disorder. I leave out of account the dropsy which begins in the flanks or in
any other susceptible part; this clearly confutes Erasistratus' assumption,
although not so obviously as does that kind of dropsy which is brought about by
an excessive chilling of the whole constitution; this, which is the primary
reason for the occurrence of dropsy, results from a failure of
blood-production, very much like the diarrhoea which follows imperfect
digestion of food; certainly in this kind of dropsy neither the liver nor any
other viscus becomes indurated.

The learned Erasistratus, however, overlooks- nay, despises- what neither
Hippocrates, Diocles, Praxagoras, nor indeed any of the best philosophers,
whether Plato, Aristotle, or Theophrastus; he passes by whole functions as
though it were but a trifling and casual department of medicine which he was
neglecting, without deigning to argue whether or not these authorities are
right in saying that the bodily parts of all animals are governed by the Warm,
the Cold, the Dry and the Moist, the one pair being active the other passive,
and that among these the Warm has most power in connection with all functions,
but especially with the genesis of the humours. Now, one cannot be blamed for
not agreeing with all these great men, nor for imagining that one knows more
than they; but not to consider such distinguished teaching worthy either of
contradiction or even mention shows an extraordinary arrogance.

Now, Erasistratus is thoroughly small-minded and petty to the last degree in
all his disputations- when, for instance, in his treatise "On Digestion," he
argues jealously with those who consider that this is a process of putrefaction
of the food; and, in his work "On Anadosis," with those who think that the
anadosis of blood through the veins results from the contiguity of the
arteries; also, in his work "On Respiration," with those who maintain that the
air is forced along by contraction. Nay, he did not even hesitate to contradict
those who maintain that the urine passes into the bladder in a vaporous state,
as also those who say that imbibed fluids are carried into the lung. Thus he
delights to choose always the most valueless doctrines, and to spend his time
more and more in contradicting these; whereas on the subject of the origin of
blood (which is in no way less important than the chylification of food in the
stomach) he did not deign to dispute with any of the ancients, nor did he
himself venture to bring forward any other opinion, despite the fact that at
the beginning of his treatise on "General Principles" he undertook to say how
all the various natural functions take place, and through what parts of the
animal! Now, is it possible that, when the faculty which naturally digests food
is weak, the animal's digestion fails, whereas the faculty which turns the
digested food into blood cannot suffer any kind of impairment? Are we to
suppose this latter faculty alone to be as tough as steel and unaffected by
circumstances? Or is it that weakness of this faculty will result in something
else than dropsy? The fact, therefore, that Erasistratus, in regard to other
matters, did not hesitate to attack even the most trivial views, whilst in this
he neither dared to contradict his predecessors nor to advance any new view of
his own, proves plainly that he recognized the fallacy of his own way of

For what could a man possibly say about blood who had no use for innate heat?
What could he say about yellow or black bile, or phlegm? Well, of course, he
might say that the bile could come directly from without, mingled with the
food! Thus Erasistratus practically says so in the following words: "It is of
no value in practical medicine to find out whether fluid of this kind arises
from the elaboration of food in the stomach-region, or whether it reaches the
body because it is mixed with the food taken in from outside." But my very good
Sir, you most certainly maintain also that this humour has to be evacuated from
the animal, and that it causes great pain if it be not evacuated. How, then, if
you suppose that no good comes from the bile, do you venture to say that an
investigation into its origin is of no value in medicine?

Well, let us suppose that it is contained in the food, and not specifically
secreted in the liver (for you hold these two things possible). In this case,
it will certainly make a considerable difference whether the ingested food
contains a minimum or a maximum of bile; for the one kind is harmless, whereas
that containing a large quantity of bile, owing to the fact that it cannot be
properly purified in the liver, will result in the various affections-
particularly jaundice- which Erasistratus himself states to occur where there
is much bile. Surely, then, it is most essential for the physician to know in
the first place, that the bile is contained in the food itself from outside,
and, secondly, that for example, beet contains a great deal of bile, and bread
very little, while olive oil contains most, and wine least of all, and all the
other articles of diet different quantities. Would it not be absurd for any one
to choose voluntarily those articles which contain more bile, rather than those
containing less?

What, however, if the bile is not contained in the food, but comes into
existence in the animal's body? Will it not also be useful to know what state
of the body is followed by a greater, and what by a smaller occurrence of bile?
For obviously it is in our power to alter and transmute morbid states of the
body- in fact, to give them a turn for the better. But if we did not know in
what respect they were morbid or in what way they diverged from the normal, how
should we be able to ameliorate them?

Therefore it is not useless in treatment, as Erasistratus says, to know the
actual truth about the genesis of bile. Certainly it is not impossible, or even
difficult to discover that the reason why honey produces yellow bile is not
that it contains a large quantity of this within itself, but because it [the
honey] undergoes change, becoming altered and transmuted into bile. For it
would be bitter to the taste if it contained bile from the outset, and it would
produce an equal quantity of bile in every person who took it. The facts,
however, are not so. For in those who are in the prime of life, especially if
they are warm by nature and are leading a life of toil, the honey changes
entirely into yellow bile. Old people, however, it suits well enough, inasmuch
as the alteration which it undergoes is not into bile, but into blood.
Erasistratus, however, in addition to knowing nothing about this, shows no
intelligence even in the division of his argument; he says that it is of no
practical importance to investigate whether the bile is contained in the food
from the beginning or comes into existence as a result of gastric digestion. He
ought surely to have added something about its genesis in liver and veins,
seeing that the old physicians and philosophers declare that it along with the
blood is generated in these organs. But it is inevitable that people who, from
the very outset, go astray, and wander from the right road, should talk such
nonsense, and should, over and above this, neglect to search for the factors of
most practical importance in medicine.

Having come to this poi in the argument, I should like to ask those who declare
that Erasistratus was very familiar with the Peripatetics, whether they know
what Aristotle stated and demonstrated with regard to our bodies being
compounded out of the Warm, the Cold, the Dry and the Moist, and how he says
that among these the Warm is the most active, and that those animals which are
by nature warmest have abundance of blood, whilst those that are colder are
entirely lacking in blood, and consequently in winter lie idle and motionless,
lurking in holes like corpses. Further, the question of the colour of the blood
has been dealt with not only by Aristotle but also by Plato. Now I, for my
part, as I have already said, did not set before myself the task of stating
what has been so well demonstrated by the Ancients, since I cannot surpass
these men either in my views or in my method of giving them expression.
Doctrines, however, which they either stated without demonstration, as being
self-evident (since they never suspected that there could be sophists so
degraded as to contemn the truth in these matters), or else which they actually
omitted to mention at all- these I propose to discover and prove.

Now in reference to the genesis of the humours, I do not know that any one
could add anything wiser than what has been said by Hippocrates, Aristotle,
Praxagoras, Philotimus and many other among the Ancients. These men
demonstrated that when the nutriment becomes altered in the veins by the innate
heat, blood is produced when it is in moderation, and the other humours when it
is not in proper proportion. And all the observed facts agree with this
argument. Thus, those articles of food, which are by nature warmer are more
productive of bile, while those which are colder produce more phlegm. Similarly
of the periods of life, those which are naturally warmer tend more to bile, and
the colder more to phlegm. Of occupations also, localities and seasons, and,
above all, of natures themselves, the colder are more phlegmatic, and the
warmer more bilious. Also cold diseases result from and warmer ones from yellow
bile. There is not a single thing to be found which does not bear witness to
the truth of this account. How could it be otherwise? For, seeing that every
part functions in its own special way because of the manner in which the four
qualities are compounded, it is absolutely necessary that the function
[activity] should be either completely destroyed, or, at least hampered, by any
damage to the qualities, and that thus the animal should fall ill, either as a
whole, or in certain of its parts.

Also the diseases which are primary and most generic are four in number, and
differ from each other in warmth, cold, dryness and moisture. Now, Erasistratus
himself confesses this, albeit unintentionally; for when he says that the
digestion of food becomes worse in fever, not because the innate heat has
ceased to be in due proportion, as people previously supposed, but because the
stomach, with its activity impaired, cannot contract and triturate as before-
then, I say, one may justly ask him what it is that has impaired the activity
of the stomach.

Thus, for example, when a bubo develops following an accidental wound gastric
digestion does not become impaired until the patient has become fevered;
neither the bubo nor the sore of itself impedes in any way or damages the
activity of the stomach. But if fever occurs, the digestion at once
deteriorates, and we are also right in saying that the activity of the stomach
at once becomes impaired. We must add, however, by what it has been impaired.
For the wound was not capable of impairing it, nor yet the bubo, for, if they
had been, then they would have caused this damage before the fever as well. If
it was not these that caused it, then it was the excess of heat (for these two
symptoms occurred besides the bubo- an alteration in the arterial and cardiac
movements and an excessive development of natural heat). Now the alteration of
these movements will not merely not impair the function of the stomach in any
way: it will actually prove an additional help among those animals in which,
according to Erasistratus, the pneuma, which is propelled through the arteries
and into the alimentary canal, is of great service in digestion; there is only
left, then, the disproportionate heat to account for the damage to the gastric
activity. For the pneuma is driven in more vigorously and continuously, and in
greater quantity now than before; thus in this case, the animal whose digestion
is promoted by pneuma will digest more, whereas the remaining factor- abnormal
heat- will give them indigestion. For to say, on the one hand, that the pneuma
has a certain property by virtue of which it promotes digestion, and then to
say that this property disappears in cases of fever, is simply to admit the
absurdity. For when they are again asked what it is that has altered the
pneuma, they will only be able to reply, "the abnormal heat," and particularly
if it be the pneuma in the food canal which is in question (since this does not
come in any way near the bubo).

Yet why do I mention those animals in which the property of the pneuma plays an
important part, when it is possible to base one's argument upon human beings,
in whom it is either of no importance at all, or acts quite faintly and feebly?
But Erasistratus himself agrees that human beings digest badly in fevers,
adding as the cause that the activity of the stomach has been impaired. He
cannot, however, advance any other cause of this impairment than abnormal heat.
But if it is not by accident that the abnormal heat impairs this activity, but
by virtue of its own essence and power, then this abnormal heat must belong to
the primary diseases. But, indeed, if disproportion of heat belongs to the
primary diseases, it cannot but be that a proportionate blending [eucrasia] of
the qualities produces the normal activity. For a disproportionate blend
[dyscrasia] can only become a cause of the primary diseases through derangement
of the eucrasia. That is to say, it is because the [normal] activities arise
from the eucrasia that the primary impairments of these activities necessarily
arise the from derangement.

I think, then, it has been proved to the satisfaction of those who are capable
of seeing logical consequences, that, even according to Erasistratus' own
argument, the cause of the normal functions is eucrasia of the Warm. Now, this
being so, there is nothing further to prevent us from saying that, in the case
of each function, eucrasia is followed by the more, and dyscrasia by the less
favourable alternative. And, therefore, if this be the case, we must suppose
blood to be the outcome of proportionate, and yellow bile of disproportionate
heat. So we naturally find yellow bile appearing in greatest quantity in
ourselves at the warm periods of life, in warm countries, at warm seasons of
the year, and when we are in a warm condition; similarly in people of warm
temperaments, and in connection with warm occupations, modes of life, or

And to be in doubt as to whether this humour has the genesis in the human body
or is contained in the food is what you would expect from one who has- I will
not say failed to see that, when those who are perfectly healthy have, under
the compulsion of circumstances, to fast contrary to custom, their mouths
become bitter and their urine bile-coloured, while they suffer from gnawing
pains in the stomach- but has, as it were, just made a sudden entrance into the
world, and is not yet familiar with the phenomena which occur there. Who, in
fact, does not know that anything which is overcooked grows at first salt and
afterwards bitter? And if you will boil honey itself, far the sweetest of all
things, you can demonstrate that even this becomes quite bitter. For what may
occur as a result of boiling in the case of other articles which are not warm
by nature, exists naturally in honey; for this reason it does not become
sweeter on being boiled, since exactly the same quantity of heat as is needed
for the production of sweetness exists from beforehand in the honey. Therefore
the external heat, which would be useful for insufficiently warm substances,
becomes in the honey a source of damage, in fact an excess; and it is for this
reason that honey, when boiled, can be demonstrated to become bitter sooner
than the others. For the same reason it is easily transmuted into bile in those
people who are naturally warm, or in their prime, since warm when associated
with warm becomes readily changed into a disproportionate combination and turns
into bile sooner than into blood. Thus we need a cold temperament and a cold
period of life if we would have honey brought to the nature of blood. Therefore
Hippocrates not improperly advised those who were naturally bilious not to take
honey, since they were obviously of too warm a temperament. So also, not only
Hippocrates, but all physicians say that honey is bad in bilious diseases but
good in old age; some of them having discovered this through the indications
afforded by its nature, and others simply through experiment, for the
Empiricist physicians too have made precisely the same observation, namely,
that honey is good for an old man and not for a young one, that it is harmful
for those who are naturally bilious, and serviceable for those who are
phlegmatic. In a word, in bodies which are warm either through nature, disease,
time of life, season of the year, locality, or occupation, honey is productive
of bile, whereas in opposite circumstances it produces blood.

But surely it is impossible that the same article of diet can produce in
certain persons bile and in others blood, if it be not that the genesis of
these humours is accomplished in the body. For if all articles of food
contained bile from the beginning and of themselves, and did not produce it by
undergoing change in the animal body, then they would produce it similarly in
all bodies; the food which was bitter to the taste would, I take it, be
productive of bile, while that which tasted good and sweet would not generate
even the smallest quantity of bile. Moreover, not only honey but all other
sweet substances are readily converted into bile in the aforesaid bodies which
are warm for any of the reasons mentioned.

Well, I have somehow or other been led into this discussion,- not in accordance
with my plan, but compelled by the course of the argument. This subject has
been treated at great length by Aristotle and Praxagoras, who have correctly
expounded the view of Hippocrates and Plato.

9. For this reason the things that we have said are not to be looked upon as
proofs but rather as indications of the dulness of those who think differently,
and who do not even recognise what is agreed on by everyone and is a matter of
daily observation. As for the scientific proofs of all this, they are to be
drawn from these principles of which I have already spoken- namely, that bodies
act upon and are acted upon by each other in virtue of the Warm, Cold, Moist
and Dry. And if one is speaking of any activity, whether it be exercised by
vein, liver, arteries, heart, alimentary canal, or any part, one will be
inevitably compelled to acknowledge that this activity depends upon the way in
which the four qualities are blended. Thus I should like to ask the
Erasistrateans why it is that the stomach contracts upon the food, and why the
veins generate blood. There is no use in recognizing the mere fact of
contraction, without also knowing the cause; if we know this, we shall also be
able to rectify the failures of function. "This is no concern of ours," they
say; "we do not occupy ourselves with such causes as these; they are outside
the sphere of the practitioner, and belong to that of the scientific
investigator." Are you, then, going to oppose those who maintain that the cause
of the function of every organ is a natural eucrasia, that the dyscrasia is
itself known as a disease, and that it is certainly by this that the activity
becomes impaired? Or, on the other hand, will you be convinced by the proofs
which the ancient writers furnished? Or will you take a midway course between
these two, neither perforce accepting these arguments as true nor contradicting
them as false, but suddenly becoming sceptics- Pyrrhonists, in fact? But if you
do this you will have to shelter yourselves behind the Empiricist teaching. For
how are you going to be successful in treatment, if you do not understand the
real essence of each disease? Why, then, did you not call yourselves
Empiricists from the beginning? Why do you confuse us by announcing that you
are investigating natural activities with a view to treatment? If the stomach
is, in a particular case, unable to exercise its peristaltic and grinding
functions, how are we going to bring it back to the normal if we do not know
the cause of its disability? What I say is that we must cool the over-heated
stomach and warm the warm the chilled one; so also we must moisten the one
which has become dried up, and conversely; so, too, in combinations of these
conditions; if the stomach becomes at the same time warmer and drier than
normally, the first principle of treatment is at once to chill and moisten it;
and if it become colder and moister, it must be warmed and dried; so also in
other cases. But how on earth are the followers of Erasistratus going to act,
confessing as they do that they make no sort of investigation into the cause of
disease? For the fruit of the enquiry into activities is that by knowing the
causes of the dyscrasiae one may bring them back to the normal, since it is of
no use for the purposes of treatment merely to know what the activity of each
organ is.

Now, it seems to me that Erasistratus is unaware of this fact also, that the
actual disease is that condition of the body which, not accidentally, but
primarily and of itself, impairs the normal function. How, then, is he going to
diagnose or cure diseases if he is entirely ignorant of what they are, and of
what kind and number? As regards the stomach, certainly, Erasistratus held that
one should at least investigate how it digests the food. But why was not
investigation also made as to the primary originative cause of this? And, as
regards the veins and the blood, he omitted even to ask the question "how?"

Yet neither Hippocrates nor any of the other physicians or philosophers whom I
mentioned a short while ago thought it right to omit this; they say that when
the heat which exists naturally in every animal is well blended and moderately
moist it generates blood; for this reason they also say that the blood is a
virtually warm and moist humour, and similarly also that yellow bile is warm
and dry, even though for the most part it appears moist. (For in them the
apparently dry would seem to differ from the virtually dry.) Who does not know
that brine and sea-water preserve meat and keep it uncorrupted, whilst all
other water- the drinkable kind- readily spoils and rots it? And who does not
know that when yellow bile is contained in large quantity in the stomach, we
are troubled with an unquenchable thirst, and that when we vomit this up, we at
once become much freer from thirst than if we had drunk very large quantities
of fluid? Therefore this humour has been very properly termed warm, and also
virtually dry. And, similarly, phlegm has been called cold and moist; for about
this also clear proofs have been given by Hippocrates and the other Ancients.

Prodicus also, when in his book "On the Nature of Man" he gives the name
"phlegm" to that element in the humours which has been burned or, as it were,
over-roasted, while using a different terminology, still keeps to the fact just
as the others do; this man's innovations in nomenclature have also been amply
done justice to by Plato. Thus, the white-coloured substance which everyone
else calls phlegm, and which Prodicus calls blenna [mucus], is the well-known
cold, moist humour which collects mostly in old people and in those who have
been chilled in some way, and not even a lunatic could say that this was
anything else than cold and moist.

If, then, there is a warm and moist humour, and another which is warm and dry,
and yet another which is moist and cold, is there none which is virtually cold
and dry? Is the fourth combination of temperaments, which exists in all other
things, non-existent in the humours alone? No; the black bile is such a humour.
This, according to intelligent physicians and philosophers, tends to be in
excess, as regards seasons, mainly in the fall of the year, and, as regards
ages, mainly after the prime of life. And, similarly, also they say that there
are cold and dry modes of life, regions, constitutions, and diseases. Nature,
they suppose, is not defective in this single combination; like the three other
combinations, it extends everywhere.

At this point, also, I would gladly have been able to ask Erasistratus whether
his "artistic" Nature has not constructed any organ for clearing away a humour
such as this. For whilst there are two organs for the excretion of urine, and
another of considerable size for that of yellow bile, does the humour which is
more pernicious than these wander about persistently in the veins mingled with
the blood? Yet Hippocrates says, "Dysentery is a fatal condition if it proceeds
from black bile"; while that proceeding from yellow bile is by no means deadly,
and most people recover from it; this proves how much more pernicious and acrid
in its potentialities is black than yellow bile. Has Erasistratus, then, not
read the book, "On the Nature of Man," any more than any of the rest of
Hippocrates' writings, that he so carelessly passes over the consideration of
the humours? Or, does the know it, and yet voluntarily neglect one of the
finest studies in medicine? Thus he ought not to have said anything about the
spleen, nor have stultified himself by holding that an artistic Nature would
have prepared so large an organ for no purpose. As a matter of fact, not a
matter of fact, not only Hippocrates and Plato- who are no less authorities on
Nature than is Erasistratus- say that this viscus also is one of those which
cleanse the blood, but there are thousands of the ancient physicians and
philosophers as well who are in agreement with them. Now, all of these the high
and mighty Erasistratus affected to despise, and he neither contradicted them
nor even so much as mentioned their opinion. Hippocrates, indeed, says that the
spleen wastes in those people in whom the body is in good condition, and all
those physicians also who base themselves on experience agree with this. Again,
in those cases in which the spleen is large and is increasing from internal
suppuration, it destroys the body and fills it with evil humours; this again is
agreed on, not only by Hippocrates, but also by Plato and many others,
including the Empiric physicians. And the jaundice which occurs when the spleen
is out of order is darker in colour, and the cicatrices of ulcers are dark.
For, generally speaking, when the spleen is drawing the atrabiliary humour into
itself to a less degree than is proper, the blood is unpurified, and the whole
body takes on a bad colour. And when does it draw this in to a less degree than
proper? Obviously, when it [the spleen] is in a bad condition. Thus, just as
the kidneys, whose function it is to attract the urine, do this badly when they
are out or order, so also the spleen, which has in itself a native power of
attracting an atrabiliary quality,if it ever happens to be weak, must
necessarily exercise this attraction badly, with the result that the blood
becomes thicker and darker.

Now all these points, affording as they do the greatest help in the diagnosis
and in the cure of disease were entirely passed over by Erasistratus, and he
pretended to despise these great men- he who does not despise ordinary people,
but always jealously attacks the most absurd doctrines. Hence, it was clearly
because he had nothing to say against the statements made by the Ancients
regarding the function and utility of the spleen, and also because he could
discover nothing new himself, that he ended by saying nothing at all. I,
however, for my part, have demonstrated, firstly from the causes by which
everything throughout nature is governed (by the causes I mean the Warm, Cold,
Dry and Moist) and secondly, from obvious bodily phenomena, that there must
needs be a cold and dry humour. And having in the next place drawn attention to
the fact that this humour is black bile [atrabiliary] and that the viscus which
clears it away is the spleen- having pointed this out by help of as few as
possible of the proofs given by ancient writers, I shall now proceed to what
remains of the subject in hand.

What else, then, remains but to explain clearly what it is that happens in the
generation of the humours, according to the belief and demonstration of the
Ancients? This will be more clearly understood from a comparison. Imagine,
then, some new wine which has been not long ago pressed from the grape, and
which is fermenting and undergoing alteration through the agency of its
contained heat. Imagine next two residual substances produced during this
process of alteration, the one tending to be light and air-like and the other
to be heavy and more of the nature of earth; of these the one, as I understand,
they call the flower and the other the lees. Now you may correctly compare
yellow bile to the first of these, and black bile to the latter, although these
humours have not the same appearance when the animal is in normal health as
that which they often show when it is not so; for then the yellow bile becomes
vitelline, being so termed because it becomes like the yolk of an egg, both in
colour and density; and again, even the black bile itself becomes much more
malignant than when in its normal condition, but no particular name has been
given to [such a condition of] the humour, except that some people have called
it corrosive or acetose, because it also becomes sharp like vinegar and
corrodes the animal's body- as also the earth, if it be poured out upon it- and
it produces a kind of fermentation and seething, accompanied by bubbles- an
abnormal putrefaction having become added to the natural condition of the black
humour. It seems to me also that most of the ancient physicians give the name
black humour and not black bile to the normal portion of this humour, which is
discharged from the bowel and which also frequently rises to the top [of the
stomach-contents]; and they call black bile that part which, through a kind of
combustion and putrefaction, has had its quality changed to acid. There is no
need, however, to dispute about names, but we must realise the facts, which are
as follow:-

In the genesis of blood, everything in the nutriment which belongs naturally to
the thick and earth-like part of the food, and which does not take on well the
alteration produced by the innate heat- all this the spleen draws into itself.
On the other hand, that part of the nutriment which is roasted, so to speak, or
burnt (this will be the warmest and sweetest part of it, like honey and fat),
becomes yellow bile, and is cleared away through the so-called biliary vessels;
now, this is thin, moist, and fluid, not like what it is when, having been
roasted to an excessive degree, it becomes yellow, fiery, and thick, like the
yolk of eggs; for this latter is already abnormal, while the previously
mentioned state is natural. Similarly with the black humour: that which does
not yet produce, as I say, this seething and fermentation on the ground, is
natural, while that which has taken over this character and faculty is
unnatural; it has assumed an acridity owing to the combustion caused by
abnormal heat, and has practically become transformed into ashes. In somewhat
the same way burned lees differ from unburned. The former is a warm substance,
able to burn, dissolve, and destroy the flesh. The other kind, which has not
yet undergone combustion, one may find the physicians employing for the same
purposes that one uses the so-called potter's earth and other substances which
have naturally a combined drying and chilling action.

Now the vitelline bile also may take on the appearance of this combusted black
bile, if ever it chance to be roasted, so to say, by fiery heat. And all the
other forms of bile are produced, some the from blending of those mentioned,
others being, as it were, transition-stages in the genesis of these or in their
conversion into one another. And they differ in that those first mentioned are
unmixed and unique, while the latter forms are diluted with various kinds of
serum. And all the serums in the humours are waste substances, and the animal
body needs to be purified from them. There is, however, a natural use for the
humours first mentioned, both thick and thin; the blood is purified both by the
spleen and by the bladder beside the liver, and a part of each of the two
humours is put away, of such quantity and quality that, if it were carried all
over the body, it would do a certain amount of harm. For that which is
decidedly thick and earthy in nature, and has entirely escaped alteration in
the liver, is drawn by the spleen into itself; the other part which is only
moderately thick, after being elaborated [in the liver], is carried all over
the body. For the blood in many parts of the body has need of a certain amount
of thickening, as also, I take it, of the fibres which it contains. And the use
of these has been discussed by Plato, and it will also be discussed by me in
such of my treatises as may deal with the use of parts. And the blood also
needs, not least, the yellow humour, which has as yet not reached the extreme
stage of combustion; in the treatises mentioned it will be pointed out what
purpose is subserved by this.

Now Nature has made no organ for clearing away phlegm, this being cold and
moist, and, as it were, half-digested nutriment; such a substance, therefore,
does not need to be evacuated, but remains in the body and undergoes alteration
there. And perhaps one cannot properly give the name of phlegm to the
surplus-substance which runs down from the brain, but one should call it mucus
[blenna] or coryza- as, in fact, it is actually termed; in any case it will be
pointed out, in the treatise "On the Use of Parts," how Nature has provided for
the evacuation of this substance. Further, the device provided by Nature which
ensures that the phlegm which forms in the stomach and intestines may be
evacuated in the most rapid and effective way possible- this also will be
described in that commentary. As to that portion of the phlegm which is carried
in the veins, seeing that this is of service to the animal, it requires no
evacuation. Here too, then, we must pay attention and recognise that, just as
in the case of each of the two kinds of bile, there is one part which is useful
to the animal and in accordance with its nature, while the other part is
useless and contrary to nature, so also is it with the phlegm; such of it as is
sweet is useful to the animal and according to nature, while, as to such of it
as has become bitter or salt, that part which is bitter is completely
undigested, while that part which is salt has undergone putrefaction. And the
term "complete indigestion" refers of course to the second digestion- that
which takes place in the veins; it is not a failure of the first digestion-
that in the alimentary canal- for it would not have become a humour at the
outset if it had escaped this digestion also.

It seems to me that I have made enough reference to what has been said
regarding the genesis and destruction of humours by Hippocrates, Plato,
Aristotle, Praxagoras, and Diocles, and many others among the Ancients; I did
not deem it right to transport the whole of their final pronouncements into
this treatise. I have said only so much regarding each of the humours as will
stir up the reader, unless he be absolutely inept, to make himself familiar
with the writings of the Ancients, and will help him to gain more easy access
to them. In another treatise I have written on the humours according to
Praxagoras, to Praxagoras, son of authority Nicarchus; although this authority
makes as many as ten humours, not including the blood (the blood itself being
an eleventh), this is not a departure from the teaching of Hippocrates; for
Praxagoras divides into species and varieties the humours which Hippocrates
first mentioned, with the demonstration proper to each.

Those, then, are to be praised who explain the points which have been duly
mentioned, as also those who add what has been left out; for it is not possible
for the same man to make both a beginning and an end. Those, on the other hand,
deserve censure who are so impatient that they will not wait to learn any of
the things which have been duly mentioned, as do also those who are so
ambitious that, in their lust after novel doctrines, they are always attempting
some fraudulent sophistry, either purposely neglecting certain subjects, as
Erasistratus does in the case of the humours, or unscrupulously attacking other
people, as does this same writer, as well as many of the more recent

But let this discussion come to an end here, and I shall add in the third book
all that remains.



1. It has been made clear in the preceding discussion that nutrition occurs by an
alteration or assimilation of that which nourishes to that which receives
nourishment, and that there exists in every part of the animal a faculty which
in view of its activity we call, in general terms, alterative, or, more
specifically, assimilative and nutritive. It was also shown that a sufficient
supply of the matter which the part being nourished makes into nutriment for
itself is ensured by virtue of another faculty which naturally attracts its
proper juice [humour] that juice is proper to each part which is adapted for
assimilation, and that the faculty which attracts the juice is called, by
reason of its activity, attractive or epispastic. It has also been shown that
assimilation is preceded by adhesion, and this, again, by presentation, the
latter stage being, as one might say, the end or goal of the activity
corresponding to the attractive faculty. For the actual bringing up of
nutriment from the veins into each of the parts takes place through the
activation of the attractive faculty, whilst to have been finally brought up
and presented to the part is the actual end for which we desired such an
activity; it is attracted in order that it may be presented. After this,
considerable time is needed for the nutrition of the animal; whilst a thing may
be even rapidly attracted, on the other hand to become adherent, altered, and
entirely assimilated to the part which is being nourished and to become a part
of it, cannot take place suddenly, but requires a considerable amount of time.
But if the nutritive juice, so presented, does not remain in the part, but
withdraws to another one, and keeps flowing away, and constantly changing and
shifting its position, neither adhesion nor complete assimilation will take
place in any of them. Here too, then, the [animal's] nature has need of some
other faculty for ensuring a prolonged stay of the presented juice at the part,
and this not a faculty which comes in from somewhere outside but one which is
resident in the part which is to be nourished. This faculty, again, in view of
its activity our predecessors were obliged to call retentive.

Thus our argument has clearly shown the necessity for the genesis of such a
faculty, and whoever has an appreciation of logical sequence must be firmly
persuaded from what we have said that, if it be laid down and proved by
previous demonstration that Nature is artistic and solicitous for the animal's
welfare, it necessarily follows that she must also possess a faculty of this

2. Since, however, it is not our habit to employ this kind of demonstration alone,
but to add thereto cogent and compelling proofs drawn from obvious facts, we
will also proceed to the latter kind in the present instance: we will
demonstrate that in certain parts of the body the retentive faculty is so
obvious that its operation can be actually recognised by the senses, whilst in
other parts it is less obvious to the senses, but is capable even here of being
detected by the argument.

Let us begin our exposition, then, by first dealing systematically for a while
with certain definite parts of the body, in reference to which we may
accurately test and enquire what sort of thing the retentive faculty is.

Now, could one begin the enquiry in any better way than with the largest and
hollowest organs? Personally I do not think one could. It is to be expected
that in these, owing to their size, the activities will show quite clearly,
whereas with respect to the small organs, even if they possess a strong faculty
of this kind, its activation will not at once be recognisable to sense.

Now those parts of the animal which are especially hollow and large are the
stomach and the organ which is called the womb or uterus. What prevents us,
then, from taking up these first and considering their activities, conducting
the enquiry on our own persons in regard to those activities which are obvious
without dissection, and, in the case of those which are more obscure,
dissecting animals which are near to man; not that even animals unlike him will
not show, in a general way, the faculty in question, but because in this manner
we may find out at once what is common to all and what is peculiar to
ourselves, and so may become more resourceful in the diagnosis and treatment of

Now it is impossible to speak of both organs at once, so we shall deal with
each in turn, beginning with the one which is capable of demonstrating the
retentive faculty most plainly. For the stomach retains the food until it has
quite digested it, and the uterus retains the embryo until it brings it to
completion, but the time taken for the completion of the embryo is many times
more than that for the digestion of food.

3. We may expect, then, to detect the retentive faculty in the uterus more clearly
in proportion to the longer duration of its activity as compared with that of
the stomach. For, as we know, it takes nine months in most women for the foetus
to attain maturity in the womb, this organ having its neck quite closed, and
entirely surrounding the embryo together with the chorion. Further, it is the
utility of the function which determines the closure of the os and the stay of
the foetus in the uterus. For it is not casually nor without reason that Nature
has made the uterus capable of contracting upon, and of retaining the embryo,
but in order that the latter may arrive at a proper size. When, therefore, the
object for which the uterus brought its retentive faculty into play has been
fulfilled, it then stops this faculty and brings it back to a state of rest,
and employs instead of it another faculty hitherto quiescent- the propulsive
faculty. In this case again the quiescent and active states are both determined
by utility; when this calls, there is activity; when it does not, there is

Here, then, once more, we must observe well the Art [artistic tendency] of
Nature- how she has not merely placed in each organ the capabilities of useful
activities, but has also fore-ordained the times both of rest and movement. For
everything connected with the pregnancy proceeds properly, the eliminative
faculty remains quiescent as though it did not exist, but if anything goes
wrong in connection either with the chorion or any of the other membranes or
with the foetus itself, and its completion is entirely despaired of, then the
uterus no longer awaits the nine-months period, but the retentive faculty
forthwith ceases and allows the heretofore inoperative faculty to come into
action. Now it is that something is done- in fact, useful work effected- by the
eliminative or propulsive faculty (for so it, too, has been called, receiving,
like the rest,its names from the corresponding activities).

Further, our theory can, I think, demonstrate both together; for seeing that
they succeed each other, and that the one keeps giving place to the other
according as utility demands, it seems not unreasonable to accept a common
demonstration also for both. Thus it is the work of the retentive faculty to
make the uterus contract upon the foetus at every point, so that, naturally
enough, when the midwives palpate it, the os is found to be closed, whilst the
pregnant women themselves, during the first days- and particularly on that on
which conception takes place- experience a sensation as if the uterus were
moving and contracting upon itself. Now, if both of these things occur- if the
os closes apart from inflammation or any other disease, and if this is
accompanied by a feeling of movement in the uterus- then the women believe that
they have received the semen which comes from the male, and that they are
retaining it.

Now we are not inventing this for ourselves: one may say the statement is based
on prolonged experience of those who occupy themselves with such matters. Thus
Herophilus does not hesitate to state in his writings that up to the time of
labour the os uteri will not admit so much as the tip of a probe, that it no
longer opens to the slightest degree if pregnancy has begun- that, in fact, it
dilates more widely at the times of the menstrual flow. With him are in
agreement all the others who have applied themselves to this subject; and
particularly Hippocrates, who was the first of all physicians and philosophers
to declare that the os uteri closes during pregnancy and inflammation, albeit
in pregnancy it does not depart from its own nature, whilst in inflammation it
becomes hard.

In the case of the opposite (the eliminative) faculty, the os opens, whilst the
whole fundus approaches as near as possible to the os, expelling the embryo as
it does so; and along with the fundus the contiguous parts- which form as it
were a girdle round the whole organ- cooperate in the work; they squeeze upon
the embryo and propel it bodily outwards. And, in many women who exercise such
a faculty immoderately, violent pains cause forcible prolapse of the whole
womb; here almost the same thing happens as frequently occurs in wresting-bouts
and struggles, when in our eagerness to overturn and throw others we are
ourselves upset along with them; for similarly when the uterus is forcing the
embryo forward it sometimes becomes entirely prolapsed, and particularly when
the ligaments connecting it with the spine happen to be naturally lax.

A wonderful device of Nature's also is this- that, when the foetus is alive,
the os uteri is closed with perfect accuracy, but if it dies, the os at once
opens up to the extent which is necessary for the foetus to make its exit. The
midwife, however, does not make the parturient woman get up at once and sit
down on the [obstetric] chair, but she begins by palpating the os as it
gradually dilates, and the first thing she says is that it has dilated "enough
to admit the little finger," then that "it is bigger now," and as we make
enquiries from time to time, she answers that the size of the dilatation is
increasing. And when it is sufficient to allow of the transit of the foetus,
she then makes the patient get up from her bed and sit on the chair, and bids
her make every effort to expel the child. Now, this additional work which the
patient does of herself is no longer the work of the uterus but of the
epigastric muscles, which also help us in defaecation and micturition.

4. Thus the two faculties are clearly to be seen in the case of the uterus; in the
case of the stomach they appear as follows:- Firstly in the condition of
gurgling, which physicians are persuaded, and with reason, to be a symptom of
weakness of the stomach; for sometimes when the very smallest quantity of food
has been ingested this does not occur, owing to the fact that the stomach is
contracting accurately upon the food and constricting it at every point;
sometimes when the stomach is full the gurglings yet make themselves heard as
though it were empty. For if it be in a natural condition, employing its
contractile faculty in the ordinary way, then, even if its contents be very
small, it grasps the whole of them and does not leave any empty space. When it
is weak, however, being unable to lay hold of its contents accurately, it
produces a certain amount of vacant space, and amount of vacant space, and
allows the liquid contents to flow about in different directions in accordance
with its changes of shape, and so to produce gurglings.

Thus those who are troubled with this symptom expect, with good reason, that
they will also be unable to digest adequately; proper digestion cannot take
place in a weak stomach. In such people also, the mass of food may be plainly
seen to remain an abnormally long time in the stomach, as would be natural if
their digestion were slow. Indeed, the chief way in which these people will
surprise one is in the length of time that not food alone but even fluids will
remain in their stomachs. Now, the actual cause of this is not, as one would
imagine, that the lower outlet of the stomach, being fairly narrow, will allow
nothing to pass before being reduced to a fine state of division. There are a
great many people who frequently swallow large quantities of big fruit-stones;
one person who was holding a gold ring in his mouth, inadvertently swallowed
it; another swallowed a coin, and various people have swallowed various hard
and indigestible objects; yet all these people easily passed by the bowel what
they had swallowed, without there being any subsequent symptoms. Now surely if
narrowness of the gastric outlet were the cause of untriturated food remaining
for an abnormally long time, none of these articles I have mentioned would ever
have escaped. Furthermore, the fact that it is liquids which remain longest in
these people's stomachs is sufficient to put the idea of narrowness of the
outlet out of court. For, supposing a rapid descent were dependent upon
emulsification, then soups, milk, and barley-emulsion would at once pass along
in every case. But as a matter of fact this is not so. For in people who are
extremely asthenic it is just these fluids which remain undigested, which
accumulate and produce gurglings, and which oppress and overload the stomach,
whereas in strong persons not merely do none of these things happen, but even a
large quantity of bread or meat passes rapidly down.

And it is not only because the stomach is distended and loaded and because the
fluid runs from one part of it to another accompanied by gurglings- it is not
only for these reasons that one would judge that there was an unduly long
continuance of the food in it, in those people who are so disposed, but also
from the vomiting. Thus, there are some who vomit up every particle of what
they have eaten, not after three or four hours, but actually in the middle of
the night, a lengthy period having elapsed since their meal.

Suppose you fill any animal whatsoever with liquid food- an experiment I have
often carried out in pigs, to whom I give a sort of mess of wheaten flour and
water, there after cutting them open after three or four hours; if you will do
this yourself, you will find the food still in the stomach. For it is not
chylification which determines the length of its stay here- since this can also
be effected outside the stomach; the determining factor is digestion which is a
different thing from chylification, as are blood-production and nutrition. For,
just as it has been shown that these two processes depend upon a change of
qualities, similarly also the digestion of food in the stomach involves a
transmutation of it into the quality proper to that which is receiving
nourishment. Then, when it is completely digested, the lower outlet opens and
the food is quickly ejected through it, even if there should be amongst it
abundance of stones, bones, grape-pips, or other things which cannot be reduced
to chyle. And you may observe this yourself in an animal, if you will try to
hit upon the time at which the descent of food from the stomach takes place.
But even if you should fail to discover the time, and nothing was yet passing
down, and the food was still undergoing digestion in the stomach, still even
then you would find dissection not without its uses. You will observe, as we
have just said, that the pylorus is accurately closed, and that the whole
stomach is in a state of contraction upon the food very much as the womb
contracts upon the foetus. For it is never possible to find a vacant space in
the uterus, the stomach, or in either of the two bladders- that is, either in
that called bile-receiving or in the other; whether their contents be abundant
or scanty, their cavities are seen to be replete and full, owing to the fact
that their coats contract constantly upon the contents- so long, as least, as
the animal is in a natural condition.

Now Erasistratus for some reason declares that it is the contractions of the
stomach which are the cause of everything- that is to say, of the softening of
the food, the removal of waste matter, and the absorption of the food when
chylified [emulsified].

Now I have personally, on countless occasions, divided the peritoneum of a
still living animal and have always found all the intestines contracting
peristaltically upon their contents. The condition of the stomach, however, is
found less simple; as regards the substances freshly swallowed, it had grasped
these accurately both above and below, in fact at every point, and was as
devoid of movement as though it had grown round and become united with the
food. At the same time I found the pylorus persistently closed and accurately
shut, like the os uteri on the foetus.

In the cases, however, where digestion had been completed the pylorus had
opened, and the stomach was undergoing peristaltic movements, similar to those
of the intestines.

5. Thus all these facts agree that the stomach, uterus, and bladders possess
certain inborn faculties which are retentive of their own proper qualities and
eliminative of those that are foreign. For it has been already shown that the
bladder by the liver draws bile into itself, while it is also quite obvious
that it eliminates this daily into the stomach. Now, of course, if the
eliminative were to succeed the attractive faculty and there were not a
retentive faculty between the two, there would be found, on every occasion that
animals were dissected, an equal quantity of bile in the gall-bladder. This
however, we do not find. For the bladder is sometimes observed to be very full,
sometimes quite empty, while at other times you find in it various intermediate
degrees of fulness, just as is the case with the other bladder- that which
receives the urine; for even without resorting to anatomy we may observe that
the urinary bladder continues to collect urine up to the time that it becomes
uncomfortable through the increasing quantity of urine or the irritation caused
by its acidity- the presumption thus being that here, too, there is a retentive

Similarly, too, the stomach, when, as often happens, it is irritated by
acidity, gets rid of the food, although still undigested, earlier than proper;
or again, when oppressed by the quantity of its contents, or disordered from
the co-existence of both conditions, it is seized with diarrhoea. Vomiting also
is an affection of the upper [part of the] stomach analogous to diarrhoea, and
it occurs when the stomach is overloaded or is unable to stand the quality of
the food or surplus substances which it contains. Thus, when such a condition
develops in the lower parts of the stomach, while the parts about the inlet are
normal, it ends in diarrhoea, whereas if this condition is in the upper
stomach, the lower parts being normal, it ends in vomiting.

6. This may often be clearly in those who are disinclined for food; when obliged
to eat, they have not the strength to swallow, and, even if they force
themselves to do so, they cannot retain the food, but at vomit it up. And those
especially who have a dislike to some particular kind of food, sometimes take
it under compulsion, and then promptly bring it up; or, if they force
themselves to keep it down, they are nauseated and feel their stomach turned
up, and endeavouring to relieve itself of its discomfort.

Thus, as was said at the beginning, all the observed facts testify that there
must exist in almost all parts of the animal a certain inclination towards, or,
so to speak, an appetite for their own special quality, and an aversion to, or,
as it were, a hatred of the foreign quality. And it is natural that when they
feel an inclination they should attract, and that when they feel aversion they
should expel.

From these facts, then, again, both the attractive and the propulsive faculties
have been demonstrated to exist in everything.

But if there be an inclination or attraction, there will also be some benefit
derived; for no existing thing attracts anything else for the mere sake of
attracting, but in order to benefit by what is acquired by the attraction. And
of course it cannot benefit by it if it cannot retain it. Herein, then, again,
the retentive faculty is shown to have its necessary origin: for the stomach
obviously inclines towards its own proper qualities and turns away from those
that are foreign to it.

But if it aims at and attracts its food and benefits by it while retaining and
contracting upon it, we may also expect that there will be some termination to
the benefit received, and that thereafter will come the time for the exercise
of the eliminative faculty.

7. But if the stomach both retains and benefits by its food, then it employs it
for the end for which it [the stomach] naturally exists. And it exists to
partake of that which is of a quality befitting and proper to it. Thus it
attracts all the most useful parts of the food in a vaporous and finely divided
condition, storing this up in its own coats, and applying it to them. And when
it is sufficiently full it puts away from it, as one might something
troublesome, the rest of the food, this having itself meanwhile obtained some
profit from its association with the stomach. For it is impossible for two
bodies which are adapted for acting and being acted upon to come together
without either both acting or being acted upon, or else one acting and the
other being acted upon. For if their forces are equal they will act and be
acted upon equally, and if the one be much superior in strength, it will exert
its activity upon its passive neighbour; thus, while producing a great and
appreciable effect, it will itself be acted upon either little or not at all.
But it is herein also that the main difference lies between nourishing food and
a deleterious drug; the latter masters the forces of the body, whereas the
former is mastered by them.

There cannot, then, be food which is suited for the animal which is not also
correspondingly subdued by the qualities existing in the animal. And to be
subdued means to undergo alteration. Now, some parts are stronger in power and
others weaker; therefore, while all will subdue the nutriment which is proper
to the animal, they will not all do so equally. Thus the stomach will subdue
and alter its food, but not to the same extent as will the liver, veins,
arteries, and heart.

We must therefore observe to what extent it does alter it. The alteration is
more than that which occurs in the mouth, but less than that in the liver and
veins. For the latter alteration changes the nutriment into the substance of
blood, whereas that in the mouth obviously changes it into a new form, but
certainly does not completely transmute it. This you may discover in the food
which is left in the intervals between the teeth, and which remains there all
night; the bread is not exactly bread, nor the meat meat, for they have a smell
similar to that of the animal's mouth, and have been disintegrated and
dissolved, and have had the qualities of the animal's flesh impressed upon
them. And you may observe the extent of the alteration which occurs to food in
the mouth if you will chew some corn and then apply it to an unripe
[undigested] boil: you will see it rapidly transmuting- in fact entirely
digesting- the boil, though it cannot do anything of the kind if you mix it
with water. And do not let this surprise you; this phlegm [saliva] in the mouth
is also a cure for lichens; it even rapidly destroys scorpions; while, as
regards the animals which emit venom, some it kills at once, and others after
an interval; to all of them in any case it does great damage. Now, the
masticated food is all, firstly, soaked in and mixed up with this phlegm; and
secondly, it is brought into contact with the actual skin of the mouth; thus it
undergoes more change than the food which is wedged into the vacant spaces
between the teeth.

But just as masticated food is more altered than the latter kind, so is food
which has been swallowed more altered than that which has been merely
masticated. Indeed, there is no comparison between these two processes; we have
only to consider what the stomach contains- phlegm, bile, pneuma, [innate]
heat, and, indeed the whole substance of the stomach. And if one considers
along with this the adjacent viscera like a lot of burning hearths around a
great cauldron- to the right the liver, to the left the spleen, the heart
above, and along with it the diaphragm (suspended and in a state of constant
movement), and the omentum sheltering them all- you may believe what an
extraordinary alteration it is which occurs in the food taken into the stomach.

How could it easily become blood if it were not previously prepared by means of
a change of this kind? It has already been shown that nothing is altered all at
once from one quality to its opposite. How then could bread, beef, beans, or
any other food turn into blood if they had not previously undergone some other
alteration? And how could the faeces be generated right away in the small
intestine? For what is there in this organ more potent in producing alteration
than the factors in the stomach? Is it the number of the coats, or the way it
is surrounded by neighbouring viscera, or the time that the food remains in it,
or some kind of innate heat which it contains? Most assuredly the intestines
have the advantage of the stomach in none of these respects. For what possible
reason, then, will objectors have it that bread may often remain a whole night
in the stomach and still preserve its original qualities, whereas when once it
is projected into the intestines, it straightway becomes ordure? For, if such a
long period of time is incapable of altering it, neither will the short period
be sufficient, or, if the latter is enough, surely the longer time will be much
more so! Well, then, can it be that, while the nutriment does undergo an
alteration in the stomach, this is a different kind of alteration and one which
is not dependent on the nature of the organ which alters it? Or if it be an
alteration of this latter kind, yet one perhaps which is not proper to the body
of the animal? This is still more impossible. Digestion was shown to be nothing
else than an alteration to the quality proper to that which is receiving
nourishment. Since, then, this is what digestion means and since the nutriment
has been shown to take on in the stomach a quality appropriate to the animal
which is about to be nourished by it, it has been demonstrated adequately that
nutriment does undergo digestion in the stomach.

And Asclepiades is absurd when he states that the quality of the digested food
never shows itself either in eructations or in the vomited matter, or on
dissection. For of course the mere fact that the food smells of the body shows
that it has undergone gastric digestion. But this man is so foolish that, when
he hears the Ancients saying that the food is converted in the stomach into
something "good," he thinks it proper to look out not for what is good in its
possible effects, but for what is good to the taste: this is like saying that
apples (for so one has to argue with him) become more apple-like [in flavour]
in the stomach, or honey more honey-like!

Erasistratus, however, is still more foolish and absurd, either through not
perceiving in what sense the Ancients said that digestion is similar to the
process of boiling, or because he purposely confused himself with sophistries.
It is, he says, inconceivable that digestion, involving as it does such
trifling warmth, should be related to the boiling process. This is as if we
were to suppose that it was necessary to put the fires of Etna under the
stomach before it could manage to alter the food; or else that, while it was
capable of altering the food, it did not do this by virtue of its innate heat,
which of course was moist, so that the word boil was used instead of bake.

What he ought to have done, if it was facts that he wished to dispute about,
was to have tried to show, first and foremost, that the food is not transmuted
or altered in quality by the stomach at all, and secondly, if he could not be
confident of this, he ought to have tried to show that this alteration was not
of any advantage to the animal. If, again, he were unable even to make this
misrepresentation, he ought to have attempted to confute the postulate
concerning the active principles- to show, in fact, that the functions taking
place in the various parts do not depend on the way in which the Warm, Cold,
Dry, and Moist are mixed, but on some other factor. And if he had not the
audacity to misrepresent facts even so far as this, still he should have tried
at least to show that the Warm is not the most active of all the principles
which play a part in things governed by Nature. But if he was unable to
demonstrate this any more than any of the previous propositions, then he ought
not to have made himself ridiculous by quarrelling uselessly with a mere name-
as though Aristotle had not clearly stated in the fourth book of his
"Meteorology," as well as in many other passages, in what way digestion can be
said to be allied to boiling, and also that the latter expression is not used
in its primitive or strict sense.

But, as has been frequently said already, the one starting-point of all this is
a thorough-going enquiry into the question of the Warm, Cold, Dry and Moist;
this Aristotle carried out in the second of his books "On Genesis and
Destruction," where he shows that all the transmutations and alterations
throughout the body take place as a result of these principles. Erasistratus,
however, advanced nothing against these or anything else that has been said
above, but occupied himself merely with the word "boiling."

8. Thus, as regards digestion, even though he neglected everything else, he did at
least attempt to prove his point- namely, that digestion in animals differs
from boiling carried on outside; in regard to the question of deglutition,
however, he did not go even so far as this. What are his words?

"The stomach does not appear to exercise any traction."

Now the fact is that the stomach possesses two coats, which certainly exist for
some purpose; they extend as far as the mouth, the internal one remaining
throughout similar to what it is in the stomach, and the other one tending to
become of a more fleshy nature in the gullet. Now simple observation will
testify that these coats have their fibres inserted in contrary directions.
And, although Erasistratus did not attempt to say for what reason they are like
this, I am going to do so.

The inner coat has its fibres straight, since it exists for the purpose of
traction. The outer coat has its fibres transverse, for the purpose of
peristalsis. In fact, the movements of each of the mobile organs of the body
depend on the setting of the fibres. Now please test this assertion first in
the muscles themselves; in these the fibres are most distinct, and their
movements visible owing to their vigour. And after the muscles, pass to the
physical organs, and you will see that they all move in correspondence with
their fibres. This is why the fibres throughout the intestines are circular in
both coats- they only contract peristaltically, they do not exercise traction.
The stomach, again, has some of its fibres longitudinal for the purpose of
traction and the others transverse for the purpose of peristalsis. For just as
the movements in the muscles take place when each of the fibres becomes
tightened and drawn towards its origin, such also is what happens in the
stomach; when the transverse fibres tighten, the breadth of the cavity
contained by them becomes less; and when the longitudinal fibres contract and
draw in upon themselves, the length must necessarily be curtailed. This
curtailment of length, indeed, is well seen in the act of swallowing: the
larynx is seen to rise upwards to exactly the same degree that the gullet is
drawn downwards; while, after the process of swallowing has been completed and
the gullet is released from tension, the larynx can be clearly seen to again.
This is because the inner coat of the stomach, which has the longitudinal
fibres and which also lines the gullet and the mouth, extends to the interior
of the larynx, and it is thus impossible for it to be drawn down by the stomach
without the larynx being involved in the traction.

Further, it will be found acknowledged in Erasistratus's own writings that the
circular fibres (by which the stomach as well as other parts performs its
contractions) do not curtail its length, but contract and lessen its breadth.
For he says that the stomach contracts peristaltically round the food during
the whole period of digestion. But if it contracts, without in any way being
diminished in length, this is because downward traction of the gullet is not a
property of the movement of circular peristalsis. For what alone happens, as
Erasistratus himself said, is that when the upper parts contract the lower ones
dilate. And everyone knows that this can be plainly seen happening even in a
dead man, if water be poured down his throat; this symptom results from the
passage of matter through a narrow channel; it would be extraordinary if the
channel did not dilate when a mass was passing through it. Obviously then the
dilatation of the lower parts along with the contraction of the upper is common
both to dead bodies, when anything whatsoever is passing through them, and to
living ones, whether they contract peristaltically round their contents or
attract them.

Curtailment of length, on the other hand, is peculiar to organs which possess
longitudinal fibres for the purpose of attraction. But the gullet was shown to
be pulled down; for otherwise it would not have drawn upon the larynx. It is
therefore clear that the stomach attracts food by the gullet.

Further, in vomiting, the mere passive conveyance of rejected matter up to the
mouth will certainly itself suffice to keep open those parts of the oesophagus
which are distended by the returned food; as it occupies each part in front
[above], it first dilates this, and of course leaves the part behind [below]
contracted. Thus, in this respect at least, the condition of the gullet is
precisely similar to what it is in the act of swallowing. But there being no
traction, the whole length remains equal in such cases.

And for this reason it is easier to swallow than to vomit, for deglutition
results the coats of the stomach being brought into action, the inner one
exerting a pull and the outer one helping by peristalsis and propulsion,
whereas emesis occurs from the outer coat alone functioning, without there
being any kind of pull towards the mouth. For, although the swallowing of food
is ordinarily preceded by a feeling of desire on the part of the stomach, there
is in the case of vomiting no corresponding desire from the mouth-parts for the
experience; the two are opposite dispositions of the stomach itself; it yearns
after and tends towards what is advantageous and proper to it, it loathes and
rids itself of what is foreign. Thus the actual process of swallowing occurs
very quickly in those who have a good appetite for such foods as are proper to
the stomach; this organ obviously draws them in and down before they are
masticated; whereas in the case of those who are forced to take a medicinal
draught or who take food as medicine, the swallowing of these articles is
accomplished with distress and difficulty.

From what has been said, then, it is clear that the inner coat of the stomach
(that containing longitudinal fibres) exists for the purpose of exerting a pull
the from to stomach, and that it is only in deglutition that it is active,
whereas the external coat, which contains transverse fibres, has been so
constituted in order that it may contract upon its contents and propel them
forward; this coat furthermore, functions in vomiting no less than in
swallowing. The truth of my statement is also borne out by what happens in the
channae and synodonts; the stomachs of these animals are sometimes found in
their mouths, as also Aristotle writes in his "History of Animals"; he also
adds the cause of this: he says that it is owing to their voracity.

The facts are as follows. In all animals, when the appetite is very intense,
the stomach rises up, so that some people who have a clear perception of this
condition say that their stomach "creeps out" of them; in others, who are still
masticating their food and have not yet worked it up properly in the mouth, the
stomach obviously snatches away the food from them against their will. In those
animals, therefore, which are naturally voracious, in whom the mouth cavity is
of generous proportions, and the stomach situated close to it (as in the case
of the synodont and channae), it is in no way surprising that, when they are
sufficiently hungry and are pursuing one of the smaller animals, and are just
on the point of catching it, the stomach should, under the impulse of desire,
spring into the mouth. And this cannot possibly take place in any other way
than by the stomach drawing the food to itself by means of the gullet, as
though by a hand. In fact, just as we ourselves, in our eagerness to grasp more
quickly something lying before us, sometimes stretch out our whole bodies along
with our hands, so also the stomach stretches itself forward along with the
gullet, which is, as it were, its hand. And thus, in these animals in whom
those three factors co-exist- an excessive propensity for food, a small gullet,
and ample mouth proportions- in these, any slight tendency to movement forwards
brings the whole stomach into the mouth.

Now the constitution of the organs might itself suffice to give a naturalist an
indication of their functions. For Nature would never have purposelessly
constructed the oesophagus of two coats with contrary dispositions; they must
also have each been meant to have a different action. The Erasistratean school,
however, are capable of anything rather than of recognizing the effects of
Nature. Come, therefore, let us demonstrate to them by animal dissection as
well that each of the two coats does exercise the activity which I have stated.
Take an animal, then; lay bare the structures surrounding the gullet, without
severing any of the nerves, arteries, or veins which are there situated; next
divide with vertical incisions, from the lower jaw to the thorax, the outer
coat of the oesophagus (that containing transverse fibres); then give the
animal food and you will see that it still swallows although the peristaltic
function has been abolished. If, again, in another animal, you cut through both
coats with transverse incisions, you will observe that this animal also
swallows although the inner coat is no longer functioning. From this it is
clear that the animal can also swallow by either of the two coats, although not
so well as by both. For the following also, in addition to other points, may be
distinctly observed in the dissection which I have described- that during
deglutition the gullet becomes slightly filled with air which is swallowed
along with the food, and that, when the outer coat is contracting, this air is
easily forced with the food into the stomach, but that, when there only exists
an inner coat, the air impedes the conveyance of food, by distending this coat
and hindering its action.

But Erasistratus said nothing about this, nor did he point out that the oblique
situation of the gullet clearly confutes the teaching of those who hold that it
is simply by virtue of the impulse from above that food which is swallowed
reaches the stomach. The only correct thing he said was that many of the
longnecked animals bend down to swallow. Hence, clearly, the observed fact does
not show how we swallow but how we do not swallow. For from this observation it
is clear that swallowing is not due merely to the impulse from above; it is
yet, however, not clear whether it results from the food being attracted by the
stomach, or conducted by the gullet. For our part, however, having enumerated
all the different considerations- those based on the constitution of the
organs, as well as those based on the other symptoms which, as just mentioned,
occur both before and after the gullet has been exposed- we have thus
sufficiently proved that the inner coast exists for the purpose of attraction
and the outer for the purpose of propulsion.

Now the original task we set before ourselves was to demonstrate that the
retentive faculty exists in every one of the organs, just as in the previous
book we proved the existence of the attractive, and, over and above this, the
alterative faculty. Thus, in the natural course of our argument, we have
demonstrated these four faculties existing in the stomach- the attractive
faculty in connection with swallowing, the retentive with digestion, the
expulsive with vomiting and with the descent of digested food into the small
intestine- and digestion itself we have shown to be a process of alteration.

9. Concerning the spleen, also, we shall therefore have no further doubts as to
whether it attracts what is proper to it, rejects what is foreign, and has a
natural power of altering and retaining all that it attracts; nor shall we be
in any doubt as to the liver, veins, arteries, heart, or any other organ. For
these four faculties have been shown to be necessary for every part which is to
be nourished; this is why we have called these faculties the handmaids of
nutrition. For just as human faeces are most pleasing to dogs, so the residual
matters from the liver are, some of them, proper to the spleen, others to the
gall-bladder, and others to the kidneys.

10. I should not have cared to say anything further as to the origin of these
[surplus substances] after Hippocrates, Plato, Aristotle, Diocles, Praxagoras,
and Philotimus, nor indeed should I even have said anything about the
faculties, if any of our predecessors had worked out this subject thoroughly.

While, however, the statements which the Ancients made on these points were
correct, they yet omitted to defend their arguments with logical proofs; of
course they never suspected that there could be sophists so shameless as to try
to contradict obvious facts. More recent physicians, again, have been partly
conquered by the sophistries of these fellows and have given credence to them;
whilst others who attempted to argue with them appear to me to lack to a great
extent the power of the Ancients. For this reason I have attempted to put
together my arguments in the way in which it seems to me the Ancients, had any
of them been still alive, would have done, in opposition to those who would
overturn the finest doctrines of our art.

I am not, however, unaware that I shall achieve either nothing at all or else
very little. For I find that a great many things which have been conclusively
demonstrated by the Ancients are unintelligible to the bulk of the Moderns
owing to their ignorance- nay, that, by reason of their laziness, they will not
even make an attempt to comprehend them; and even if any of them have
understood them, they have not given them impartial examination.

The fact is that he whose purpose is to know anything better than the multitude
do must far surpass all others both as regards his nature and his early
training. And when he reaches early adolescence he must become possessed with
an ardent love for truth, like one inspired; neither day nor night may he cease
to urge and strain himself in order to learn thoroughly all that has been said
by the most illustrious of the Ancients. And when he has learnt this, then for
a prolonged period he must test and prove it, observing what part of it is in
agreement, and what in disagreement with obvious fact; thus he will choose this
and turn away from that. To such an one my hope has been that my treatise would
prove of the very greatest assistance.... Still, such people may be expected to
be quite few in number, while, as for the others, this book will be as
superfluous to them as a tale told to an ass.

11. For the sake, then, of those who are aiming at truth, we must complete this
treatise by adding what is still wanting in it. Now, in people who are very
hungry, the stomach obviously attracts or draws down the food before it has
been thoroughly softened in the mouth, whilst in those who have no appetite or
who are being forced to eat, the stomach is displeased and rejects the food.
And in a similar way of the other organs possesses both faculties- that of
attracting what is proper to it, and that of rejecting what is foreign. Thus,
even if there be any organ which consists of only one coat (such as the two
bladders, the uterus, and the veins), it yet possesses both kinds of fibres,
the longitudinal and the transverse.

But further, there are fibres of a third kind- the oblique- which are much
fewer in number than the two kinds already spoken of. In the organs consisting
of two coats this kind of fibre is found in the one coat only, mixed with the
longitudinal fibres; but in the organs composed of one coat it is found along
with the other two kinds. Now, these are of the greatest help to the action of
the faculty which we have named retentive. For during this period the part
needs to be tightly contracted and stretched over its contents at every point-
the stomach during the whole period of digestion, and the uterus during that of

Thus too, the coat of a vein, being single, consists of various kinds of
fibres; whilst the outer coat of an artery consists of circular fibres, and its
inner coat mostly of longitudinal fibres, but with a few oblique ones also
amongst them. Veins thus resemble the uterus or the bladder as regards the
arrangement of their fibres, even though they are deficient in thickness;
similarly arteries resemble the stomach. Alone of all organs the intestines
consist of two coats of which both have their fibres transverse. Now the proof
that it was for the best that all the organs should be naturally such as they
are (that, for instance, the intestines should be composed of two coats)
belongs to the subject of the use of parts; thus we must not now desire to hear
about matters of this kind nor why the anatomists are at variance regarding the
number of coats in each organ. For these questions have been sufficiently
discussed in the treatise "On Disagreement in Anatomy." And the problem as to
why each organ has such and such a character will be discussed in the treatise
"On the Use of Parts."

12. It is not, however, our business to discuss either of these questions here, but
to consider duly the natural faculties, which, to the number of four, exist in
each organ. Returning then, to this point, let us recall what has already been
said, and set a crown to the whole subject by adding what is still wanting. For
when every part of the animal has been shewn to draw into itself the juice
which is proper to it (this being practically the first of the natural
faculties), the next point to realise is that the part does not get rid either
of this attracted nutriment as a whole, or even of any superfluous portion of
it, until either the organ itself, or the major part of its contents also have
their condition reversed. Thus, when the stomach is sufficiently filled with
the food and has absorbed and stored away the most useful part of it in its own
coats, it then rejects the rest like an alien burden. The same happens to the
bladders, when the matter attracted into them begins to give trouble either
because it distends them through its quantity or irritates them by its quality.

And this also happens in the case of the uterus; for it is either because it
can no longer bear to be stretched that it strives to relieve itself of its
annoyance, or else because it is irritated by the quality of the fluids poured
out into it. Now both of these conditions sometimes occur with actual violence,
and then miscarriage takes place. But for the most part they happen in a normal
way, this being then called not miscarriage but delivery or parturition. Now
abortifacient drugs or certain other conditions which destroy the embryo or
rupture certain of its membranes are followed by abortion, and similarly also
when the uterus is in pain from being in a bad state of tension; and, as has
been well said by Hippocrates, excessive movement on the part of the embryo
itself brings on labour. Now pain is common to all these conditions, and of
this there are three possible causes- either excessive bulk, or weight, or
irritation; bulk when the uterus can no longer support the stretching, weight
when the contents surpass its strength, and irritation when the fluids which
had previously been pent up in the membranes, flow out, on the rupture of
these, into the uterus itself, or else when the whole foetus perishes,
putrefies, and is resolved into pernicious ichors, and so irritates and bites
the coat of the uterus.

In all organs, then, both their natural effects and their disorders and
maladies plainly take place on analogous lines, some so clearly and manifestly
as to need no demonstration, and others less plainly, although not entirely
unrecognizable to those who are willing to pay attention.

Thus, to take the case of the stomach: the irritation is evident here because
this organ possesses most sensibility, and among its other affections those
producing nausea and the so-called heartburn clearly demonstrate the
eliminative faculty which expels foreign matter. So also in the case of the
uterus and the urinary bladder; this latter also may be plainly observed to
receive and accumulate fluid until it is so stretched by the amount of this as
to be incapable of enduring the pain; or it may be the quality of the urine
which irritates it; for every superfluous substance which lingers in the body
must obviously putrefy, some in a shorter, and some in a longer time, and thus
it becomes pungent, acrid, and burdensome to the organ which contains it. This
does not apply, however, in the case of the bladder alongside the liver, whence
it is clear that it possesses fewer nerves than do the other organs. Here too,
however, at least the physiologist must discover an analogy. For since it was
shown that the gall-bladder attracts its own special juice, so as to be often
found full, and that it discharges it soon after, this desire to discharge must
be either due to the fact that it is burdened by the quantity or that the bile
has changed in quality to pungent and acrid. For while food does not change its
original quality so fast that it is already ordure as soon as it falls into the
small intestine, on the other hand the bile even more readily than the urine
becomes altered in quality as soon as ever it leaves the veins, and rapidly
undergoes change and putrefaction. Now, if there be clear evidence in relation
to the uterus, stomach, and intestines, as well as to the urinary bladder, that
there is either some distention, irritation, or burden inciting each of these
organs to elimination, there is no difficulty in imagining this in the case of
the gall-bladder also, as well as in the other organs,- to which obviously the
arteries and veins also belong.

13. Nor is there any further difficulty in ascertaining that it is through the same
channel that both attraction and discharge take place at different times. For
obviously the inlet to the stomach does not merely conduct food and drink into
this organ, but in the condition of nausea it performs the neck of the bladder
which is beside the liver, albeit single, both fills and empties the bladder.
Similarly the canal of the uterus affords an entrance to the semen and an exit
to the foetus.

But in this latter case, again, whilst the eliminative faculty is evident, the
attractive faculty is not so obvious to most people. It is, however, the cervix
which Hippocrates blames for inertia of the uterus when he says:- "Its orifice
has no power of attracting semen."

Erasistratus, however, and Asclepiades reached such heights of wisdom that they
deprived not merely the stomach and the womb of this faculty but also the
bladder by the liver, and the kidneys as well. I have, however, pointed out in
the first book that it is impossible to assign any other cause for the
secretion of urine or bile.

Now, when we find that the uterus, the stomach and the bladder by the liver
carry out attraction and expulsion through one and the same duct, we need no
longer feel surprised that Nature should also frequently discharge
waste-substances into the stomach through the veins. Still less need we be
astonished if a certain amount of the food should, during long fasts, be drawn
back from the liver into the stomach through the same veins by which it was
yielded up to the liver during absorption of nutriment. To disbelieve such
things would of course be like refusing to believe that purgative drugs draw
their appropriate humours from all over the body by the same stomata through
which absorption previously takes place, and to look for separate stomata for
absorption and purgation respectively. As a matter of fact one and the same
stoma subserves two distinct faculties, and these exercise their pull at
different times in opposite directions- first it subserves the pull of the
liver and, during catharsis, that of the drug. What is there surprising, then,
in the fact that the veins situated between the liver and the region of the
stomach fulfil a double service or purpose? Thus, when there is abundance of
nutriment contained in the food-canal, it is carried up to the liver by the
veins mentioned; and when the canal is empty and in need of nutriment, this is
again attracted from the liver by the same veins.

For everything appears to attract from and to go shares with everything else,
and, as the most divine Hippocrates has said, there would seem to be a
consensus in the movements of fluids and vapours. Thus the stronger draws and
the weaker is evacuated.

Now, one part is weaker or stronger than another either absolutely, by nature,
and in all cases, or else it becomes so in such and such a particular instance.
Thus, by nature and in all men alike, the heart is stronger than the liver at
attracting what is serviceable to it and rejecting what is not so; similarly
the liver is stronger than the intestines and stomach, and the arteries than
the veins. In each of us personally, however, liver has stronger drawing power
at one time, and the stomach at another. For when there is much nutriment
contained in the alimentary canal and the appetite and craving of the liver is
violent, then the viscus exerts far the strongest traction. Again, when the
liver is full and distended and the stomach empty and in need, then the force
of the traction shifts to the latter.

Suppose we had some food in our hands and were snatching it from one another;
if we were equally in want, the stronger would be likely to prevail, but if he
had satisfied his appetite, and was holding what was over carelessly, or was
anxious to share it with somebody, and if the weaker was excessively desirous
of it, there would be nothing to prevent the latter from getting it all. In a
similar manner the stomach easily attracts nutriment from the liver when it
[the stomach] has a sufficiently strong craving for it, and the appetite of the
viscus is satisfied. And sometimes the surplusage of nutriment in the liver is
a reason why the animal is not hungry; for when the stomach has better and more
available food it requires nothing from extraneous sources, but if ever it is
in need and is at a loss how to supply the need, it becomes filled with
waste-matters; these are certain biliary, phlegmatic [mucous] and serous
fluids, and are the only substances that the liver yields in response to the
traction of the stomach, on the occasions when the latter too is in want of

Now, just as the parts draw food from each other, so also they sometimes
deposit their excess substances in each other, and just as the stronger
prevailed when the two were exercising traction, so it is also when they are
depositing; this is the cause of the so-called fluxions, for every part has a
definite inborn tension, by virtue of which it expels its superfluities, and,
therefore, when one of these parts,- owing, of course, to some special
condition- becomes weaker, there will necessarily be a confluence into it of
the superfluities from all the other parts. The strongest part deposits its
surplus matter in all the parts near it; these again in other parts which are
weaker; these next into yet others; and this goes on for a long time, until the
superfluity, being driven from one part into another, comes to rest in one of
the weakest of all; it cannot flow from this into another part, because none of
the stronger ones will receive it, while the affected part is unable to drive
it away.

When, however, we come to deal again with the origin and cure of disease, it
will be possible to find there also abundant proofs of all that we have
correctly indicated in this book. For the present, however, let us resume again
the task that lay before us, i.e. to show that there is nothing surprising in
nutriment coming from the liver to the intestines and stomach by way of the
very veins through which it had previously been yielded up from these organs
into the liver. And in many people who have suddenly and completely given up
active exercise, or who have had a limb cut off, there occurs at certain
periods an evacuation of blood by way of the intestines- as Hippocrates has
also pointed out somewhere. This causes no further trouble but sharply purges
the whole body and evacuates the plethoras; the passage of the superfluities is
effected, of course, through the same veins by which absorption took place.

Frequently also in disease Nature purges the animal through these same veins-
although in this case the discharge is not sanguineous, but corresponds to the
humour which is at fault. Thus in cholera the entire body is evacuated by way
of the veins leading to the intestines and stomach.

To imagine that matter of different kinds is carried in one direction only
would characterise a man who was entirely ignorant of all the natural
faculties, and particularly of the eliminative faculty, which is the opposite
of the attractive. For opposite movements of matter, active and passive, must
necessarily follow opposite faculties; that is to say, every part, after it has
attracted its special nutrient juice and has retained and taken the benefit of
it hastens to get rid of all the surplusage as quickly and effectively as
possible, and this it does in accordance with the mechanical tendency of this
surplus matter.

Hence the stomach clears away by vomiting those superfluities which come to the
surface of its contents, whilst the sediment it clears away by diarrhoea. And
when the animal becomes sick, this means that the stomach is striving to be
evacuated by vomiting. And the expulsive faculty has in it so violent and
forcible an element that in cases of ileus [volvulus], when the lower exit is
completely closed, vomiting of faeces occurs; yet such surplus matter could not
be emitted from the mouth without having first traversed the whole of the small
intestine, the jejunum, the pylorus, the stomach, and the oesophagus. What is
there to wonder at, then, if something should also be transferred from the
extreme skin-surface and so reach the intestines and stomach? This also was
pointed out to us by Hippocrates, who maintained that not merely pneuma or
excess-matter, but actual nutriment is brought down from the outer surface to
the original place from which it was taken up. For the slightest mechanical
movements determine this expulsive faculty, which apparently acts through the
transverse fibres, and which is very rapidly transmitted from the source of
motion to the opposite extremities. It is, therefore, neither unlikely nor
impossible that, when the part adjoining the skin becomes suddenly oppressed by
an unwonted cold, it should at once be weakened and should find that the liquid
previously deposited beside it without discomfort had now become more of a
burden than a source of nutrition, and should therefore strive to put it away.
Finally, seeing that the passage outwards was shut off by the condensation [of
tissue], it would turn to the remaining exit and would thus forcibly expel all
the waste-matter at once into the adjacent part; this would do the same to the
part following it; and the process would not cease until the transference
finally terminated at the inner of the veins.

Now, movements like these come to an end fairly soon, but those resulting from
internal irritants (e.g., in the administration of purgative drugs or in
cholera) become much stronger and more lasting; they persist as long as the
condition of things about the mouths of the veins continues, that is, so long
as these continue to attract what is adjacent. For this condition causes
evacuation of the contiguous part, and that again of the part next to it, and
this never stops until the extreme surface is reached; thus, as each part keeps
passing on matter to its neighbour, the original affection very quickly arrives
at the extreme termination. Now this is also the case in ileus; the inflamed
intestine is unable to support either the weight or the acridity of the waste
substances and so does its best to excrete them, in fact to drive them as far
away as possible. And, being prevented from effecting an expulsion downwards
when the severest part of the inflammation is there, it expels the matter into
the adjoining part of the intestines situated above. Thus the tendency of the
eliminative faculty is step by step upwards, until the superfluities reach the

Now this will be also spoken of at greater length in my treatise on disease.
For the present, however, I think I have shown clearly that there is a
universal conveyance or transference from one thing into another, and that, as
Hippocrates used to say, there exists in everything a consensus in the movement
of air and fluids. And I do not think that anyone, however slow his intellect,
will now be at a loss to understand any of these points,- how, for instance,
the stomach or intestines get nourished, or in what manner anything makes its
way inwards from the outer surface of the body. Seeing that all parts have the
faculty of attracting what is suitable or well-disposed and of eliminating what
is troublesome or irritating, it is not surprising that opposite movements
should occur in them consecutively- as may be clearly seen in the case of the
heart, in the various arteries, in the thorax, and lungs. In all these the
active movements of the organs and therewith the passive movements of [their
contained] matters may be seen taking place almost every second in opposite
directions. Now, you are not astonished when the trachea-artery alternately
draws air into the lungs and gives it out, and when the nostrils and the whole
mouth act similarly; nor do you think it strange or paradoxical that the air is
dismissed through the very channel by which it was admitted just before. Do
you, then, feel a difficulty in the case of the veins which pass down from the
liver into the stomach and intestines, and do you think it strange that
nutriment should at once be yielded up to the liver and drawn back from it into
the stomach by the same veins? You must define what you mean by this expression
"at once." If you mean "at the same time" this is not what we ourselves say;
for just as we take in a breath at one moment and give it out again at another,
so at one time the liver draws nutriment from the stomach, and at another the
stomach from the liver. But if your expression "at once" means that in one and
the same animal a single organ subserves the transport of matter in opposite
directions, and if it is this which disturbs you, consider inspiration and
expiration. For of course these also take place through the same organs, albeit
they differ in their manner of movement, and in the way in which the matter is
conveyed through them.

Now the lungs, the thorax, the arteries rough and smooth, the heart, the mouth,
and the nostrils reverse their movements at very short intervals and change the
direction of the matters they contain. On the other hand, the veins which pass
down the from the liver to the intestines and stomach reverse the direction not
at such short intervals, but sometimes once in many days.

The whole matter, in fact, is as follows:- Each of the organs draws into itself
the nutriment alongside it, and devours all the useful fluid in it, until it is
thoroughly satisfied; this nutriment, as I have already shown, it stores up in
itself, afterwards making it adhere and then assimilating it- that is, it
becomes nourished by it. For it has been demonstrated with sufficient clearness
already that there is something which necessarily precedes actual nutrition,
namely adhesion, and that before this again comes presentation. Thus as in the
case of the animals themselves the end of eating is that the stomach should be
filled, similarly in the case of each of the parts, the end of presentation is
the filling of this part with its appropriate liquid. Since, therefore, every
part has, like the stomach, a craving to be nourished, it too envelops its
nutriment and clasps it all round as the stomach does. And this [action of the
stomach], as has been already said, is necessarily followed by the digestion of
the food, although it is not to make it suitable for the other parts that the
stomach contracts upon it; if it did so, it would no longer be a physiological
organ, but an animal possessing reason and intelligence, with the power of
choosing the better [of two alternatives].

But while the stomach contracts for the reason that the whole body possesses a
power of attracting and of utilising appropriate qualities, as has already been
explained, it also happens that, in this process, the food undergoes
alteration; further, when filled and saturated with the fluid pabulum from the
food, it thereafter looks on the food as a burden; thus it at once gets of the
excess- that is to say, drives it gets downwards- itself turning to another
task, namely that of causing adhesion. And during this time, while the
nutriment is passing along the whole length of the intestine, it is caught up
by the vessels which pass into the intestine; as we shall shortly demonstrate,
most of it is seized by the veins, but a little also by the arteries; at this
stage also it becomes presented to the coats of the intestines.

Now imagine the whole economy of nutrition divided into three periods. Suppose
that in the first period the nutriment remains in the stomach and is digested
and presented to the stomach until satiety is reached, also that some of it is
taken up from the stomach to the liver.

During the second period it passes along the intestines and becomes presented
both to them and to the liver- again until the stage of satiety- while a small
part of it is carried all over the body. During this period, also imagine that
what was presented to the stomach in the first period becomes now adherent to

During the third period the stomach has reached the stage of receiving
nourishment; it now entirely assimilates everything that had become adherent to
it: at the same time in the intestines and liver there takes place adhesion of
what had been before presented, while dispersal [anadosis] is taking place to
all parts of the body, as also presentation. Now, if the animal takes food
immediately after these [three stages] then, during the time that the stomach
is again digesting and getting the benefit of this by presenting all the useful
part of it to its own coats, the intestines will be engaged in final
assimilation of the juices which have adhered to them, and so also will the
liver: while in the various parts of the body there will be taking place
adhesion of the portions of nutriment presented. And if the stomach is forced
to remain without food during this time, it will draw its nutriment the from
the veins in the mesentery and liver; for it will not do so from the actual
body of the liver (by body of the liver I mean first and foremost its flesh
proper, and after this all the vessels contained in it), for it is irrational
to suppose that one part would draw away from another part the juice already
contained in it, especially when adhesion and final assimilation of that juice
were already taking place; the juice, however, that is in the cavity of the
veins will be abstracted by the part which is stronger and more in need.

It is in this way, therefore, that the stomach, when it is in need of
nourishment and the animal has nothing to eat, seizes it from the veins in the
liver. Also in the case of the spleen we have shown in a former passage how it
draws all material from the liver that tends to be thick, and by working it up
converts it into more useful matter. There is nothing surprising, therefore,
if, in the present instance also, some of this should be drawn from the spleen
into such organs as communicate with it by veins, e.g. the omentum, mesentery,
small intestine, colon, and the stomach itself. Nor is it surprising that the
spleen should disgorge its surplus matters into the stomach at one time, while
at another time it should draw some of its appropriate nutriment from the

For, as has already been said, speaking generally, everything has the power at
different times of attracting from and of adding to everything else. What
happens is just as if you might imagine a number of animals helping themselves
at will to a plentiful common stock of food; some will naturally be eating when
others have stopped, some will be on the point of stopping when others are
beginning, some eating together, and others in succession. Yes, by Zeus! and
one will often be plundering another, if he be in need while the other has an
abundant supply ready to hand. Thus it is in no way surprising that matter
should make its way back from the outer surface of the body to the interior, or
should be carried from the liver and spleen into the stomach by the same
vessels by which it was carried in the reverse direction.

In the case of the arteries this is clear enough, as also in the case of heart,
thorax, and lungs; for, since all of these dilate and contract alternately, it
must needs be that matter is subsequently discharged back into the parts from
which it was previously drawn. Now Nature foresaw this necessity, and provided
the cardiac openings of the vessels with membranous attachments, to prevent
their contents from being carried backwards. How and in what manner this takes
place will be stated in my work "On the Use of Parts," where among other things
I show that it is impossible for the openings of the vessels to be closed so
accurately that nothing at all can run back. Thus it is inevitable that the
reflux into the venous artery (as will also be made clear in the work
mentioned) should be much greater than through the other openings. But what it
is important for our present purpose to recognise is that every thing
possessing a large and appreciable cavity must, when it dilates, abstract
matter from all its neighbours, and, when it contracts, must squeeze matter
back into them. This should all be clear from what has already been said in
this treatise and from what Erasistratus and I myself have demonstrated
elsewhere respecting the tendency of a vacuum to become refilled.

14. And further, it has been shown in other treatises that all the arteries possess
a power which derives from the heart, and by virtue of which they dilate and

Put together, therefore, the two facts- that the arteries have this motion, and
that everything, when it dilates, draws neighbouring matter into itself- and
you will find nothing strange in the fact that those arteries which reach the
skin draw in the outer air when they dilate, while those which anastomose at
any point with the veins attract the thinnest and most vaporous part of the
blood which these contain, and as for those arteries which are near the heart,
it is on the heart itself that they exert their traction. For, by virtue of the
tendency by which a vacuum becomes refilled, the lightest and thinnest part
obeys the tendency before that which is heavier and thicker. Now the lightest
and thinnest of anything in the body is firstly pneuma, secondly vapour, and in
the third place that part of the blood which has been accurately elaborated and

These, then, are what the arteries draw into themselves on every side; those
arteries which reach the skin draw in the outer air (this being near them and
one of the lightest of things); as to the other arteries, those which pass up
from the heart into the neck, and that which lies along the spine, as also such
arteries as are near these- draw mostly from the heart itself; and those which
are farther from the heart and skin necessarily draw the lightest part of the
blood out of the veins. So also the traction exercised by the diastole of the
arteries which go to the stomach and intestines takes place at the expense of
the heart itself and the numerous veins in its neighbourhood; for these
arteries cannot get anything worth speaking of from the thick heavy nutriment
contained in the intestines and stomach, since they first become filled with
lighter elements. For if you let down a tube into a vessel full of water and
sand, and suck the air out of the tube with your mouth, the sand cannot come up
to you before the water, for in accordance with the principle of the refilling
of a vacuum the lighter matter is always the first to succeed to the

15. is not to be wondered at, therefore, that only a very little [nutrient matter]
such, namely, as has been accurately elaborated- gets from the stomach into the
arteries, since these first become filled with lighter matter. We must
understand that there are two kinds of attraction, that by which a vacuum
becomes refilled and that caused by appropriateness of quality; air is drawn
into bellows in one way, and iron by the lodestone in another. And we must also
understand that the traction which results from evacuation acts primarily on
what is light, whilst that from appropriateness of quality acts frequently, it
may be, on what is heavier (if this should be naturally more nearly related).
Therefore, in the case of the heart and the arteries, it is in so far as they
are hollow organs, capable of diastole, that they always attract the lighter
matter first, while, in so far as they require nourishment, it is actually into
their coats (which are the real bodies of these organs) that the appropriate
matter is drawn. Of the blood, then, which is taken into their cavities when
they dilate, that part which is most proper to them and most able to afford
nourishment is attracted by their actual coats.

Now, apart from what has been said, the following is sufficient proof that
something is taken over from the veins into the arteries. If you will kill an
animal by cutting through a number of its large arteries, you will find the
veins becoming empty along with the arteries: now, this could never occur if
there were not anastomoses between them. Similarly, also, in the heart itself,
the thinnest portion of the blood is drawn from the right ventricle into the
left, owing to there being perforations in the septum between them: these can
be seen for a great part [of their length]; they are like a kind of fossae
[pits] with wide mouths, and they get constantly narrower; it is not possible,
however, actually to observe their extreme terminations, owing both to the
smallness of these and to the fact that when the animal is dead all the parts
are chilled and shrunken. Here, too, however, our argument, starting from the
principle that nothing is done by Nature in vain, discovers these anastomoses
between the ventricles of the heart; for it could not be at random and by
chance that there occurred fossae ending thus in narrow terminations.

And secondly [the presence of these anastomoses has been assumed] from the fact
that, of the two orifices in the right ventricle, the one conducting blood in
and the other out, the former is much the larger. For, the fact that the
insertion of the vena cava into the heart is larger than the vein which is
inserted into the lungs suggests that not all the blood which the vena cava
gives to the heart is driven away again from the heart to the lungs. Nor can it
be said that any of the blood is expended in the nourishment of the actual body
of the heart, since there is another vein which breaks up in it and which
does not take its origin nor get its share of blood from the heart itself. And
even if a certain amount is so expended, still the vein leading to the lungs is
not to such a slight extent smaller than that inserted into the heart as to
make it likely that the blood is used as nutriment for the heart: the disparity
is much too great for such an explanation. It is, therefore, clear that
something is taken over into the left ventricle.

Moreover, of the two vessels connected with it, that which brings pneuma into
it from the lungs is much smaller than the great outgrowing artery from which
the arteries all over the body originate; this would suggest that it not merely
gets pneuma from the lungs, but that it also gets blood from the right
ventricle through the anastomoses mentioned.

Now it belongs to the treatise "On the Use of Parts" to show that it was best
that some parts of the body should be nourished by pure, thin, and vaporous
blood, and others by thick, turbid blood, and that in this matter also Nature
has overlooked nothing. Thus it is not desirable that these matters should be
further discussed. Having mentioned, however, that there are two kinds of
attraction, certain bodies exerting attraction along wide channels during
diastole (by virtue of the principle by which a vacuum becomes refilled) and
others exerting it by virtue of their appropriateness of quality, we must next
remark that the former bodies can attract even from a distance, while the
latter can only do so from among things which are quite close to them; the very
longest tube let down into water can easily draw up the liquid into the mouth,
but if you withdraw iron to a distance from the lodestone or corn from the jar
(an instance of this kind has in fact been already given) no further attraction
can take place.

This you can observe most clearly in connection with garden conduits. For a
certain amount of moisture is distributed from these into every part lying
close at hand but it cannot reach those lying farther off: therefore one has to
arrange the flow of water into all parts of the garden by cutting a number of
small channels leading from the large one. The intervening spaces between these
small channels are made of such a size as will, presumably, best allow them
[the spaces] to satisfy their needs by drawing from the liquid which flows to
them from every side. So also is it in the bodies of animals. Numerous conduits
distributed through the various limbs bring them pure blood, much like the
garden water-supply, and, further, the intervals between these conduits have
been wonderfully arranged by Nature from the outset so that the intervening
parts should be plentifully provided for when absorbing blood, and that they
should never be deluged by a quantity of superfluous fluid running in at
unsuitable times.

For the way in which they obtain nourishment is somewhat as follows. In the
body which is continuous throughout, such as Erasistratus supposes his simple
vessel to be, it is the superficial parts which are the first to make use of
the nutriment with which they are brought into contact; then the parts coming
next draw their share from these by virtue of their contiguity; and again
others from these; and this does not stop until the quality of the nutrient
substance has been distributed among all parts of the corpuscle in question.
And for such parts as need the humour which is destined to nourish them to be
altered still further, Nature has provided a kind of storehouse, either in the
form of a central cavity or else as separate caverns, or something analogous to
caverns. Thus the flesh of the viscera and of the muscles is nourished from the
blood directly, this having undergone merely a slight alteration; the bones,
however, in order to be nourished, very great change, and what blood is to
flesh marrow is to bone; in the case of the small bones, which do not possess
central cavities, this marrow is distributed in their caverns, whereas in the
larger bones which do contain central cavities the marrow is all concentrated
in these.

For, as was pointed out in the first book, things having a similar substance
can easily change into one another, whereas it is impossible for those which
are very different to be assimilated to one another without intermediate
stages. Such a one in respect to cartilage is the myxoid substance which
surrounds it, and in respect to ligaments, membranes, and nerves the viscous
liquid dispersed inside them; for each of these consists of numerous fibres,
which are homogeneous- in fact, actual sensible elements; and in the intervals
between these fibres is dispersed the humour most suited for nutrition; this
they drawn from the blood in the veins, choosing the most appropriate possible,
and now they are assimilating it step by step and changing it into their own

All these considerations, then, agree with one another, and bear sufficient
witness to the truth of what has been already demonstrated; there is thus no
need to prolong the discussion further. For, from what has been said, anyone
can readily discover in what way all the particular [vital activities] come
about. For instance, we could in this way ascertain why it is that in the case
of many people who are partaking freely of wine, the fluid which they have
drunk is rapidly absorbed through the body and almost the whole of it is passed
by the kidneys within a very short time. For here, too, the rapidity with which
the fluid is absorbed depends on appropriateness of quality, on the thinness of
the fluid, on the width of the vessels and their mouths, and on the efficiency
of the attractive faculty. The parts situated near the alimentary canal, by
virtue of their appropriateness of quality, draw in the imbibed food for their
own purposes, then the parts next to them in their turn snatch it away, then
those next again take it from these, until it reaches the vena cava, whence
finally the kidneys attract that part of it which is proper to them. Thus it is
in no way surprising that wine is taken up more rapidly than water, owing to
its appropriateness of quality, and, further, that the white clear kind of wine
is absorbed more rapidly owing to its thinness, while black turbid wine is
checked on the way and retarded because of its thickness.

These facts, also, will afford abundant proof of what has already been said
about the arteries; everywhere, in fact, such blood as is both specifically
appropriate and at the same time thin in consistency answers more readily to
their traction than does blood which is not so; this is why the arteries which,
in their diastole, absorb vapour, pneuma, and thin blood attract either none at
all or very little of the juices contained in the stomach and intestines.