Chapter XVIII: Book I: I (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[6] of the _soul_[7] and the latter as effects of the _nature_.[8] 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.

GALÊNOU

PERI PHYSIKÔN DYNAMEÔN

A

I

Epeidê to men aisthanesthai te kai kineisthai kata 1
proairesin idia tôn zôôn esti, to d' auxanesthai te kai
trephesthai koina kai tois phytois, eiê an ta men
protera tês psychês, ta de deutera tês physeôs erga. ei
de tis kai tois phytois psychês metadidôsi kai
diairoumenos autas onomazei phytikên men tautên,
aisthêtikên de tên heteran, legei men oud' houtos alla,
tê lexei d' ou pany tê synêthei kechrêtai. all' hêmeis
ge megistên lexeôs aretên saphêneian einai pepeismenoi
kai tautên eidotes || hyp' oudenos houtôs hôs hypo tôn 2
asynêthôn onomatôn diaphtheiromenên, hôs tois pollois
ethos, houtôs onomazontes hypo men psychês th' hama kai
physeôs ta zôa dioikeisthai phamen, hypo de physeôs
monês ta phyta kai to g' auxanesthai te kai trephesthai
physeôs erga phamen, ou psychês.

II

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, if it departs from this in any respect we then say that in this respect it _undergoes motion_.[9] Accordingly, when it departs in various ways from its pre-existing 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_.[10]

These two kinds of motion, then, are simple and primary, while compounded from them we have _growth_ and _decay_,[11] 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_,[12] genesis being a coming into existence,[13] and destruction being the opposite.

Now, common to all kinds of motion is _change from the pre-existing state_, while common to all conditions of rest is _retention of the pre-existing 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)[14] 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"[15] by Aristotle, and after him by Chrysippus,[16] 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, of 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;[17] 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[18] 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;[19] 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).[20] And clearly this disproves the view of those who consider the elements[21] 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[22] that which has already come into existence and has been completed by the _activity_[23] 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 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_,[24] 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[25]--for example, digestion, absorption,[26] 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.

II

Kai zêtêsomen kata tonde ton logon, hypo tinôn gignetai
dynameôn auta dê tauta kai ei dê ti allo physeôs ergon
estin.

Alla proteron ge dielesthai te chrê kai mênysai saphôs
hekaston tôn onomatôn, hois chrêsometha kata tonde ton
logon, kai eph' ho ti pheromen pragma. genêsetai de
tout' euthys ergôn physikôn didaskalia syn tais tôn
onomatôn exêgêsesin.

Hotan oun ti sôma kata mêden exallattêtai tôn
proÿparchontôn, hêsychazein auto phamen; ei d' existaito
pê, kat' ekeino kineisthai. kai toinyn epei polyeidôs
existatai, polyeidôs kai kinêthêsetai. kai gar ei leukon
hyparchon melainoito kai ei melan leukainoito, kineitai
kata chroan, kai ei glyky teôs hyparchon authis || 3
austêron ê empalin ex austêrou glyky genoito, kai tout'
an kineisthai legoito kata ton chymon. amphô de tauta te
kai ta proeirêmena kata tên poiotêta kineisthai
lechthêsetai kai ou monon ge ta kata tên chroan ê ton
chymon exallattomena kineisthai phamen, alla kai to
thermoteron ek psychroterou genomenon ê psychroteron ek
thermoterou kineisthai kai touto legomen, hôsper ge kai
ei ti xêron ex hygrou ê hygron ek xêrou gignoito. koinon
de kata toutôn hapantôn onoma pheromen tên alloiôsin.

Hen ti touto genos kinêseôs. heteron de genos epi tois
tas chôras ameibousi sômasi kai topon ek topou
metallattein legomenois, onoma de kai toutô phora.

Hautai men oun hai dyo kinêseis haplai kai prôtai,
synthetoi d' ex autôn auxêsis te kai phthisis, hotan ex
elattonos ti meizon ê ek meizonos elatton genêtai
phylatton to oikeion eidos. heterai de dyo kinêseis
genesis kai phthora, genesis men hê eis ousian agôgê,
phthora d' hê enantia.

Pasais de tais kinêsesi koinon exallaxis tou || 4
proÿparchontos, hôsper oun kai tais hêsychiais hê
phylakê tôn proÿparchontôn. all' hoti men exallattetai
kai pros tên opsin kai pros tên geusin kai pros tên
haphên haima gignomena ta sitia, synchôrousin; hoti de
kai kat' alêtheian, ouketi touth' homologousin hoi
sophistai. hoi men gar tines autôn hapanta ta toiauta
tôn hêmeterôn aisthêseôn apatas tinas kai paragôgas
nomizousin allot' allôs paschousôn, tês hypokeimenês
ousias mêden toutôn, hois eponomazetai, dechomenês; hoi
de tines einai men en autê boulontai tas poiotêtas,
ametablêtous de kai atreptous ex aiônos eis aiôna kai
tas phainomenas tautas alloiôseis tê diakrisei te kai
synkrisei gignesthai phasin hôs Anaxagoras.

Ei dê toutous ektrapomenos exelenchoimi, meizon an moi
to parergon tou ergou genoito. ei men gar ouk isasin,
hosa peri tês kath' holên tên ousian alloiôseôs
Aristotelei te kai met' auton Chrysippô gegraptai,
parakalesai chrê tois ekeinôn autous homilêsai
grammasin; ei de gignôskontes epeith' hekontes ta cheirô
pro tôn beltionôn || hairountai, mataia dêpou kai ta 5
hêmetera nomiousin. hoti de kai Hippokratês houtôs
egignôsken Aristotelous eti proteros ôn, en heterois
hêmin apodedeiktai. prôtos gar houtos hapantôn hôn ismen
iatrôn te kai philosophôn apodeiknyein epecheirêse
tettaras einai tas pasas drastikas eis allêlas
poiotêtas, hyph' hôn gignetai te kai phtheiretai panth',
hosa genesin te kai phthoran epidechetai. kai mentoi kai
to kerannysthai di' allêlôn autas holas di' holôn
Hippokratês hapantôn prôtos egnô; kai tas archas ge tôn
apodeixeôn, hôn hysteron Aristotelês metecheirisato,
par' ekeinô prôtô gegrammenas estin heurein.

Ei d' hôsper tas poiotêtas houtô kai tas ousias di'
holôn kerannysthai chrê nomizein, hôs hysteron
apephênato Zênôn ho Kittieus, ouch hêgoumai dein eti
peri toutou kata tonde ton logon epexienai. monên gar
eis ta paronta deomai gignôskesthai tên di' holês tês
ousias alloiôsin, hina mê tis ostou kai sarkos kai
neurou kai tôn allôn hekastou moriôn hoionei misgankeian
tina tô artô nomisê periechesthai kapeit' en || tô 6
sômati diakrinomenon hôs to homophylon hekaston ienai.
kaitoi pro ge tês diakriseôs haima phainetai gignomenos
ho pas artos. ei goun pampollô tis chronô mêden all' eiê
sition prospheromenos, ouden hêtton en tais phlepsin
haima periechomenon hexei. kai phanerôs touto tên tôn
ametablêta ta stoicheia tithemenôn exelenchei doxan,
hôsper oimai kai toulaion eis tên tou lychnou phloga
katanaliskomenon hapan kai ta xyla pyr mikron hysteron
gignomena.

Kaitoi to g' antilegein autois êrnêsamên, all' epei tês
iatrikês hylês ên to paradeigma kai chrêzô pros ton
paronta logon autou, dia tout' emnêmoneusa. katalipontes
oun, hôs ephên, tên pros toutous antilogian, <enon> tois
boulomenois ta tôn palaiôn ekmanthanein kax hôn hêmeis
idia peri autôn epeskemmetha.

Ton ephexês logon hapanta poiêsometha zêtountes hyper
hôn ex archês prouthemetha, posai te kai tines eisin hai
tês physeôs dynameis kai ti poiein ergon hekastê
pephyken. ergon de dêlonoti kalô to gegonos êdê kai
sympeplê||rômenon hypo tês energeias autôn, hoion to 7
haima, tên sarka, to neuron; energeian de tên drastikên
onomazô kinêsin kai tên tautês aitian dynamin. epei gar
en tô to sition haima gignesthai pathêtikê men hê tou
sitiou, drastikê d' hê tês phlebos gignetai kinêsis,
hôsautôs de kan tô metapherein ta kôla kinei men ho mys,
kineitai de ta osta, tên men tês phlebos kai tôn myôn
kinêsin energeian einai phêmi, tên de tôn sitiôn te kai
tôn ostôn symptôma te kai pathêma; ta men gar
alloioutai, ta de pheretai. tên men oun energeian
enchôrei kalein kai ergon tês physeôs, hoion tên pepsin,
tên anadosin, tên haimatôsin, ou mên to g' ergon ex
hapantos energeian; hê gar toi sarx ergon men esti tês
physeôs, ou mên energeia ge. dêlon oun, hôs thateron men
tôn onomatôn dichôs legetai, thateron d' ou.

III

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_[27] 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_.[28] 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 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."

III

Emoi men oun kai hê phleps kai tôn allôn hapantôn
hekaston dia tên ek tôn tettarôn poian krasin hôdi pôs
energein dokei. eisi de ge mên ouk oligoi tines andres
|| oud' adoxoi, philosophoi te kai iatroi, tô men thermô 8
kai tô psychrô to dran anapherontes, hypoballontes d'
autois pathêtika to xêron te kai to hygron. kai prôtos
g' Aristotelês tas tôn kata meros hapantôn aitias eis
tautas anagein peiratai tas archas, êkolouthêse d'
hysteron autô kai ho apo tês stoas choros. kaitoi
toutois men, hôs an kai autôn tôn stoicheiôn tên eis
allêla metabolên chysesi te tisi kai pilêsesin
anapherousin, eulogon ên archas drastikas poiêsasthai to
thermon kai to psychron, Aristotelei d' ouch houtôs,
alla tais tettarsi poiotêsin eis tên tôn stoicheiôn
genesin chrômenô beltion ên kai tas tôn kata meros
aitias hapasas eis tautas anagein. ti dêpot' oun en men
tois peri geneseôs kai phthoras tais tettarsi chrêtai,
en de tois meteôrologikois kai tois problêmasi kai
allothi pollachothi tais dyo monais? ei men gar hôs en
tois zôois te kai tois phytois mallon men dra to thermon
kai to psychron, hêtton de to xêron kai to hygron
apophainoito tis, isôs an echoi kai ton Hippokratên
sympsêphon; ei d' hôsautôs en || hapasin, ouket' oimai 9
synchôrêsein touto mê hoti ton Hippokratên alla mêd'
auton ton Aristotelên memnêsthai ge boulomenon hôn en
tois peri geneseôs kai phthoras ouch haplôs alla met'
apodeixeôs autos hêmas edidaxen. alla peri men toutôn
kan tois peri kraseôn, eis hoson iatrô chrêsimon,
epeskepsametha.

IV

The so-called _blood-making_[29] 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[30] faculty in the stomach, a pulsatile[31] 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.

IV

Hê d' oun dynamis hê en tais phlepsin hê haimatopoiêtikê
prosagoreuomenê kai pasa d' allê dynamis en tô pros ti
nenoêtai; prôtôs men gar tês energeias aitia, êdê de kai
tou ergou kata symbebêkos. all' eiper hê aitia pros ti,
tou gar hyp' autês genomenou monou, tôn d' allôn
oudenos, eudêlon, hoti kai hê dynamis en tô pros ti. kai
mechri g' an agnoômen tên ousian tês energousês aitias,
dynamin autên onomazomen, einai tina legontes en tais
phlepsin haimatopoiêtikên, hôsautôs de kan tê koilia
peptikên kan tê kardia sphygmikên kai kath' hekaston tôn
allôn idian tina tês || kata to morion energeias. eiper 10
oun methodô melloimen exeurêsein, hoposai te kai hopoiai
tines hai dynameis eisin, apo tôn ergôn autôn arkteon;
hekaston gar autôn hypo tinos energeias gignetai kai
toutôn hekastês proêgeitai tis aitia.

V

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_.[32] 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.[33] 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.

V

Erga toinyn tês physeôs eti men kyoumenou te kai
diaplattomenou tou zôou ta sympant' esti tou sômatos
moria, gennêthentos de koinon eph' hapasin ergon hê eis
to teleion hekastô megethos agôgê kai meta tauth' hê
mechri tou dynatou diamonê.

Energeiai d' epi trisi tois eirêmenois ergois treis ex
anankês, eph' hekastô mia, genesis te kai auxêsis kai
threpsis. all' hê men genesis ouch haplê tis energeia
tês physeôs, all' ex alloiôseôs te kai diaplaseôs esti
synthetos. hina men gar ostoun genêtai kai neuron kai
phleps kai tôn allôn hekaston, alloiousthai chrê tên
hypobeblêmenên ousian, ex hês gignetai to zôon; hina de
kai schêma to deon kai thesin kai koilotêtas tinas kai
apophyseis kai symphyseis kai talla || ta toiauta 11
ktêsêtai, diaplattesthai chrê tên alloioumenên ousian,
hên dê kai hylên tou zôou kalôn, hôs tês neôs ta xyla
kai tês eikonos ton kêron, ouk an hamartois.

Hê d' auxêsis epidosis esti kai diastasis kata mêkos kai
platos kai bathos tôn stereôn tou zôou moriôn, hônper
kai hê diaplasis ên, hê de threpsis prosthesis tois
autois aneu diastaseôs.

VI

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),[34] 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,[35] and in all the other qualities which naturally derive therefrom.[36] 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.[37] 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_[38] parts of the body, and these are to be detected not by any system, but by personal observation of dissections.[39]

Now Nature constructs bone, cartilage, nerve, membrane, ligament, vein, and so forth, at the first stage of the animal's genesis,[40] 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[41] (since for the sake of clearness these names must be used as well).

Now the peculiar[42] 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,[43] 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_,[44] of which each is simple, of these organs the coats 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[45]; 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,[46] 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,[47] the combination therewith of the structures which are inserted into them, the outgrowth into the intestine,[48] the shape of the inner cavities, and the like, have all been determined by a faculty which we call the shaping or formative faculty[49]; 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."

VI

Peri prôtês oun tês geneseôs eipômen, hên ex alloiôseôs
th' hama kai diaplaseôs elegomen gignesthai.

Katablêthentos dê tou spermatos eis tên mêtran ê eis tên
gên, ouden gar diapherei, chronois tisin hôrismenois
pampolla synistatai moria tês gennômenês ousias
hygrotêti kai xêrotêti kai psychrotêti kai thermotêti
kai tois allois hapasin, hosa toutois hepetai,
diapheronta. ta d' hepomena gignôskeis, eiper holôs
ephilosophêsas ti peri geneseôs kai phthoras; hai loipai
gar tôn haptôn onomazomenôn diaphorôn tais eirêmenais
hepontai prôtai kai malista, meta de tau||tas hai 12
geustai te kai osphrêtai kai horatai. sklêrotês men oun
kai malakotês kai glischrotês kai kraurotês kai
kouphotês kai barytês kai pyknotês kai araiotês kai
leiotês kai trachytês kai pachytês kai leptotês haptai
diaphorai kai eirêtai peri pasôn Aristotelei kalôs.
oistha de dêpou kai tas geustas te kai osphrêtas kai
horatas diaphoras. hôst', ei men tas prôtas te kai
stoicheiôdeis alloiôtikas dynameis zêtoiês, hygrotês
esti kai xêrotês kai psychrotês kai thermotês; ei de tas
ek tês toutôn kraseôs genomenas, tosautai kath' hekaston
esontai zôon, hosaper an autou ta aisthêta stoicheia
hyparchê; kaleitai d' aisthêta stoicheia ta homoiomerê
panta tou sômatos moria; kai taut' ouk ek methodou tinos
all' autoptên genomenon ekmathein chrê dia tôn anatomôn.

Ostoun dê kai chondron kai neuron kai hymena kai
syndesmon kai phleba kai panth' hosa toiauta kata tên
prôtên tou zôou genesin hê physis apergazetai dynamei
chrômenê katholou men eipein tê gennêtikê te kai
alloiô||tikê, kata meros de thermantikê te kai psyktikê 13
kai xêrantikê kai hygrantikê kai tais ek tês toutôn
kraseôs genomenais, hoion ostopoiêtikê te kai
neuropoiêtikê kai chondropoiêtikê; saphêneias gar heneka
kai toutois tois onomasi chrêsteon.

Esti goun kai hê idia sarx tou hêpatos ek toutou tou
genous kai hê tou splênos kai hê tôn nephrôn kai hê tou
pneumonos kai hê tês kardias houtô de kai tou enkephalou
to idion sôma kai tês gastros kai tou stomachou kai tôn
enterôn kai tôn hysterôn aisthêton stoicheion estin
homoiomeres te kai haploun kai asyntheton; ean gar
exelês hekastou tôn eirêmenôn tas artêrias te kai tas
phlebas kai ta neura, to hypoloipon sôma to kath'
hekaston organon haploun esti kai stoicheiôdes hôs pros
aisthêsin. hosa de tôn toioutôn organôn ek dyoin
synkeitai chitônôn ouch homoiôn men allêlois, haplou d'
hekaterou, toutôn hoi chitônes eisi ta stoicheia
kathaper tês te gastros kai tou stomachou kai tôn
enterôn kai tôn artêriôn, kai kath' hekateron ge tôn
chitônôn idios hê alloiôtikê dynamis hê ek tou para tês
|| mêtros epimêniou gennêsasa to morion, hôste tas kata 14
meros alloiôtikas dynameis tosautas einai kath' hekaston
zôon, hosaper an echê ta stoicheiôdê moria. kai men ge
kai tas energeias idias hekastô tôn kata meros anankaion
hyparchein hôsper kai tas chreias, hoion kai tôn apo tôn
nephrôn eis tên kystin diêkontôn porôn, hoi dê kai
ourêtêres kalountai. houtoi gar out' artêriai eisin,
hoti mête sphyzousi mêt' ek dyoin chitônôn synestêkasin,
oute phlebes, hoti mêth' haima periechousi mêt' eoiken
autôn ho chitôn kata ti tô tês phlebos; alla kai neurôn
epi pleon aphestêkasin ê tôn eirêmenôn.

Ti pot' oun eisin? erôta tis, hôsper anankaion on hapan
morion ê artêrian ê phleba ê neuron hyparchein ê ek
toutôn peplechthai kai mê tout' auto to nyn legomenon,
hôs idios hekastô tôn kata meros organôn estin hê ousia.
kai gar kai hai kysteis hekaterai hê te to ouron
hypodechomenê kai hê tên xanthên cholên ou monon tôn
allôn hapantôn alla kai allêlôn diapherousi kai hoi eis
to hêpar apophyomenoi || poroi, kathaper stomachoi tines 15
apo tês cholêdochou kysteôs, ouden out' artêriais oute
phlepsin oute neurois eoikasin. alla peri men toutôn epi
pleon en allois te tisi kan tois peri tês Hippokratous
anatomês eirêtai.

Hai de kata meros hapasai dynameis tês physeôs hai
alloiôtikai autên men tên ousian tôn chitônôn tês
koilias kai tôn enterôn kai tôn hysterôn apetelesan,
hoiaper esti; tên de synthesin autôn kai tên tôn
emphyomenôn plokên kai tên eis to enteron ekphysin kai
tên tês endon koilotêtos idean kai tall' hosa toiauta
dynamis tis hetera dieplasen, hên diaplastikên
onomazomen, hên dê kai technikên einai legomen, mallon
d' aristên kai akran technên kai panta tinos heneka
poiousan, hôs mêden argon einai mêde peritton mêd' holôs
houtôs echon, hôs dynasthai beltion heterôs echein. alla
touto men en tois peri chreias moriôn apodeixomen. || 16

VII

Passing now to the faculty of Growth[50] 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,[51] and do not possess in themselves supreme authority. When, however, the animal[52] 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.

VII

Epi de tên auxêtikên êdê metabantes dynamin auto touth'
hypomnêsômen prôton, hôs hyparchei men kai autê tois
kyoumenois hôsper kai hê threptikê; all' hoion
hypêretides tines eisi tênikauta tôn proeirêmenôn
dynameôn, ouk en hautais echousai to pan kyros. epeidan
de to teleion apolabê megethos to zôon, en tô meta tên
apokyêsin chronô panti mechri tês akmês hê men auxêtikê
tênikauta kratei; boêthoi d' autês kai hoion hypêretides
hê t' alloiôtikê dynamis esti kai hê threptikê. ti oun
to idion esti tês auxêtikês dynameôs? eis pan meros
ekteinai ta pephykota. kaleitai d' houtô ta sterea moria
tou sômatos, artêriai kai phlebes kai neura kai osta kai
chondroi kai hymenes kai syndesmoi kai hoi chitônes
hapantes, hous stoicheiôdeis te kai homoiomereis kai
haplous oligon emprosthen ekaloumen. hotô de tropô tên
eis pan meros ektasin ischousin, egô phrasô paradeigma
ti proteron eipôn heneka tou saphous. || 17

Tas kysteis tôn hyôn labontes hoi paides plêrousi te
pneumatos kai tribousin epi tês tephras plêsion tou
pyros, hôs aleainesthai men, blaptesthai de mêden; kai
pollê g' hautê hê paidia peri te tên Iônian kai en
allois ethnesin ouk oligois estin. epilegousi de dê kai
tin' epê tribontes en metrô te tini kai melei kai
rhythmô kai esti panta ta rhêmata tauta parakeleusis tê
kystei pros tên auxêsin. epeidan d' hikanôs autois
diatetasthai dokê, palin emphysôsi te kai epidiateinousi
kai authis tribousi kai touto pleonakis poiousin, achris
an autois hê kystis hikanôs echein dokê tês auxêseôs.
all' en toutois ge tois ergois tôn paidôn enargôs, hoson
eis megethos epididôsin hê entos eurychôria tês kysteôs,
tosouton anankaion eis leptotêta kathaireisthai to sôma
kai ei ge tên leptotêta tautên anatrephein hoioi t' êsan
hoi paides, homoiôs an tê physei tên kystin ek mikras
megalên apeirgazonto. nyni de tout' autois endei to
ergon oude kath' hena tropon eis mimêsin endechomenon
achthênai mê hoti tois || paisin all' oud' allô tini; 18
monês gar tês physeôs idion estin.

Hôst' êdê soi dêlon, hôs anankaia tois auxanomenois hê
threpsis. ei gar diateinoito men, anatrephoito de mê,
phantasian pseudê mallon, ouk auxêsin alêthê ta toiauta
sômata ktêsetai. kaitoi kai to diateinesthai pantê
monois tois hypo physeôs auxanomenois hyparchei. ta gar
hyph' hêmôn diateinomena sômata kata mian tina diastasin
touto paschonta meioutai tais loipais, oud' estin
heurein ouden, ho syneches eti menon kai adiaspaston eis
tas treis diastaseis epekteinai dynametha. monês oun tês
physeôs to pantê diistanai syneches heautô menon eti kai
tên archaian hapasan idean phylatton to sôma.

Kai tout' estin hê auxêsis aneu tês epirrheousês te kai
prosplattomenês trophês mê dynamenê genesthai.

VIII

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_.[53] 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_.

VIII

Kai toinyn ho logos hêkein eoiken ho peri tês threpseôs,
hos dê loipos esti kai tritos hôn ex archês
prouthemetha. tou gar epirrheontos en eidei trophês
panti || moriô tou trephomenou sômatos prosplattomenou 19
threpsis men hê energeia, threptikê de dynamis hê aitia.
alloiôsis men dê kantautha to genos tês energeias, all'
ouch hoiaper hê en tê genesei. ekei men gar ouk on
proteron hysteron egeneto, kata de tên threpsin tô êdê
gegonoti synexomoioutai to epirrheon kai dia tout'
eulogôs ekeinên men tên alloiôsin genesin, tautên d'
exomoiôsin ônomasan.

IX

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.

IX

Epeidê de peri tôn triôn dynameôn tês physeôs autarkôs
eirêtai kai phainetai mêdemias allês prosdeisthai to
zôon, echon ge kai hopôs auxêthê kai hopôs teleiôthê kai
hopôs heôs pleistou diaphylachthê, doxeie men an isôs
hikanôs echein ho logos houtos êdê kai pasas exêgeisthai
tas tês physeôs dynameis. all' ei tis palin ennoêseien,
hôs oudenos oudepô tôn tou zôou moriôn ephêpsato,
koilias legô kai enterôn kai hêpatos kai tôn homoiôn,
oud' exêgêsato tas en autois dynameis, authis doxeien an
hoion prooimion ti monon eirêsthai tês chrêsimou
didaskalias. || to gar sympan hôd' echei. genesis kai 20
auxêsis kai threpsis ta prôta kai hoion kephalaia tôn
ergôn esti tês physeôs; hôste kai hai toutôn ergastikai
dynameis hai prôtai treis eisi kai kyriôtatai; deontai
d' eis hypêresian, hôs êdê dedeiktai, kai allêlôn kai
allôn. tinôn men oun hê gennêtikê te kai auxêtikê
deontai, eirêtai, tinôn d' hê threptikê, nyn eirêsetai.

X

For I believe that I shall prove that the organs which have to do with the disposal[54] of the nutriment, as also their faculties, exist for the sake of this _nutritive faculty_. For since the action of this faculty[55] 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,[56] 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,[57] 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.[58] 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_.[59] 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[60]; it is transformed and altered and constituted useful blood; but, in the radish, what is appropriate[61] and able 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 body.

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[62] in all directions of the _utilisable_ juices. So, if you wish to gain a thorough acquaintance with all the faculties of Nature,[63] you will have to 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.[64]

X

Dokô gar moi deixein ta peri tên tês trophês oikonomian
organa te kai tas dynameis autôn dia tautên gegonota.
epeidê gar hê energeia tautês tês dynameôs exomoiôsis
estin, homoiousthai de kai metaballein eis allêla pasi
tois ousin adynaton, ei mê tina echoi koinônian êdê kai
syngeneian en tais poiotêsi, dia touto prôton men ouk ek
pantôn edesmatôn pan zôon trephesthai pephyken, epeita
d' oud' ex hôn hoion t' estin oud' ek toutôn parachrêma,
kai dia tautên tên anankên pleionôn organôn alloiôtikôn
tês trophês hekaston || tôn zôôn chrêzei. hina men gar 21
to xanthon erythron genêtai kai to erythron xanthon,
haplês kai mias deitai tês alloiôseôs; hina de to leukon
melan kai to melan leukon, hapasôn tôn metaxy. kai
toinyn kai to malakôtaton ouk an athroôs sklêrotaton kai
to sklêrotaton ouk an athroôs malakôtaton genoito,
hôsper oude to dysôdestaton euôdestaton oud' empalin to
euôdestaton dysôdestaton exaiphnês genoit' an.

Pôs oun ex haimatos ostoun an pote genoito mê
pachynthentos ge proteron epi pleiston autou kai
leukanthentos ê pôs ex artou to haima mê kata brachy men
apothemenou tên leukotêta, kata brachy de lambanontos
tên erythrotêta? sarka men gar ex haimatos genesthai
rhaston; ei gar eis tosouton auto pachyneien hê physis,
hôs systasin tina schein kai mêket' einai rhyton, hê
prôtê kai neopagês houtôs an eiê sarx; ostoun d' hina
genêtai, pollou men deitai chronou, pollês d' ergasias
kai metabolês tô haimati. hoti de kai tô artô kai poly
mallon thrida||kinê kai teutlô kai tois homoiois 22
pampollês deitai tês alloiôseôs eis haimatos genesin,
oude tout' adêlon.

Hen men dê tout' aition tou polla genesthai ta peri tên
tês trophês alloiôsin organa. deuteron d' hê tôn
perittômatôn physis. hôs gar hypo botanôn oud' holôs
dynametha trephesthai, kaitoi tôn boskêmatôn
trephomenôn, houtôs hypo rhaphanidos trephometha men,
all' ouch hôs hypo tôn kreôn. toutôn men gar oligou dein
holôn hê physis hêmôn kratei kai metaballei kai alloioi
kai chrêston ex autôn haima synistêsin; en de tê
rhaphanidi to men oikeion te kai metablêthênai
dynamenon, mogis kai touto kai syn pollê tê katergasia,
pantapasin elachiston; holê d' oligou dein esti
perittômatikê kai diexerchetai ta tês pepseôs organa,
bracheos ex autês eis tas phlebas analêphthentos
haimatos kai oude toutou teleôs chrêstou. deuteras oun
authis edeêse diakriseôs tê physei tôn en tais phlepsi
perittômatôn. kai chreia kai toutois hodôn te tinôn
heterôn epi tas ek||kriseis auta paragousôn, hôs mê 23
lymainoito tois chrêstois, hypodochôn te tinôn hoion
dexamenôn, en hais hotan eis hikanon plêthos aphikêtai,
tênikaut' ekkrithêsetai.

Deuteron dê soi kai touto to genos tôn en tô sômati
moriôn exeurêtai tois perittômasi tês trophês
anakeimenon. allo de triton hyper tou pantê pheresthai,
kathaper tines hodoi pollai dia tou sômatos holou
katatetmêmenai.

Mia men gar eisodos hê dia tou stomatos hapasi tois
sitiois, ouch hen de to trephomenon alla pampolla te kai
pampoly diestôta. mê toinyn thaumaze to plêthos tôn
organôn, hosa threpseôs heneken hê physis edêmiourgêse.
ta men gar alloiounta proparaskeuazei tên epitêdeion
hekastô moriô trophên, ta de diakrinei ta perittômata,
ta de parapempei, ta d' hypodechetai, ta d' ekkrinei, ta
d' hodoi tês pantê phoras eisi tôn chrêstôn chymôn,
hôst', eiper boulei tas dynameis tês physeôs hapasas
ekmathein, hyper hekastou toutôn an eiê soi tôn organôn
episkepteon.

Archê d' autôn tês didaskalias, hosa || tou telous engys 24
erga te tês physeôs esti kai moria kai dynameis autôn.

XI

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 nourishments_.[65] And in order that this may come about, we must assume a preliminary process of _adhesion_,[66] and for that, again, one of _presentation_.[67] 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,[68] 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_,[69] nor has it acquired that viscous and agglutinative quality which results from the operation of _innate heat_;[70] 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 nutriment_.

XI

Autou de dê palin anamnêsteon hêmin tou telous, houper
heneka tosauta te kai toiauta tê physei dedêmiourgêtai
moria. to men oun onoma tou pragmatos, hôsper kai
proteron eirêtai, threpsis; ho de kata tounoma logos
homoiôsis tou trephontos tô trephomenô. hina d' hautê
genêtai, proêgêsasthai chrê prosphysin, hina d' ekeinê,
prosthesin. epeidan gar ekpesê tôn angeiôn ho mellôn
threpsein hotioun tôn tou zôou moriôn chymos, eis hapan
auto diaspeiretai prôton, epeita prostithetai kapeita
prosphyetai kai teleôs homoioutai.

Dêlousi d' hai kaloumenai leukai tên diaphoran
homoiôseôs te kai prosphyseôs, hôsper to genos ekeino
tôn hyderôn, ho tines onomazousin ana sarka, diorizei
saphôs prosthesin prosphyseôs. ou gar endeia dêpou tês
epirrheousês hygrotêtos, hôs eniai tôn atrophiôn te kai
phthiseôn, hê tou toioutou genesis hyderou || 25
synteleitai. phainetai gar hikanôs hê te sarx hygra kai
diabrochos hekaston te tôn stereôn tou sômatos moriôn
hôsautôs diakeimenon. alla prosthesis men tis gignetai
tês epipheromenês trophês, hate d' hydatôdesteras ousês
eti kai mê pany ti kechymômenês mêde to glischron ekeino
kai kollôdes, ho dê tês emphytou thermasias oikonomia
prosgignetai, kektêmenês hê prosphysis adynatos estin
epiteleisthai plêthei leptês hygrotêtos apeptou
diarrheousês te kai rhadiôs olisthainousês apo tôn
stereôn tou sômatos moriôn tês trophês. en de tais
leukais prosphysis men tis gignetai tês trophês, ou mên
exomoiôsis ge. kai dêlon en tôde to mikrô prosthen
rhêthen hôs orthôs elegeto to dein prosthesin men
prôton, ephexês de prosphysin, epeit' exomoiôsin
genesthai tô mellonti trephesthai.

Kyriôs men oun to trephon êdê trophê, to d' hoion men
trophê, oupô de trephon, hopoion esti to prosphyomenon ê
prostithemenon, trophê men ou kyriôs, homônymôs de
trophê; to d' en tais phlepsin eti periechomenon || kai 26
toutou mallon eti to kata tên gastera tô mellein pote
threpsein, ei kalôs katergastheiê, keklêtai trophê. kata
tauta de kai tôn edesmatôn hekaston trophên onomazomen
oute tô trephein êdê to zôon oute tô toiouton hyparchein
hoion to trephon, alla tô dynasthai te kai mellein
trephein, ei kalôs katergastheiê.

Touto gar ên kai to pros Hippokratous legomenon; "Trophê
de to trephon, trophê kai to hoion trophê kai to
mellon." to men gar homoioumenon êdê trophên ônomase, to
d' hoion men ekeino prostithemenon ê prosphyomenon hoion
trophên; to d' allo pan, hoson en tê gastri kai tais
phlepsi periechetai, mellon.

XII

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 others.

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.