BOOK II

94cf.p. 36,note 2.

95The morbid material passed successively through the stages of “crudity,” “coction” (pepsis), and “elimination” (crisis). For “critical days”cf.p. 74,note 1.

96This was the process by which nutriment was taken up from the alimentary canal; “absorption,” “dispersal;”cf.p. 13,note 5. The subject is dealt with more fully inchap. xvi.

97Lit.catharsis.

98i.e.urine.

99On use of κενόωv.p. 67,note 9.

100i.e.bile and phlegm had no existence as such before the drugs were given; they are the products of dissolved tissue. Asclepiades did not believe that diseases were due to amateria peccans, but to disturbances in the movements of the molecules (ὄγκοι) which constitute the body; thus, in opposition to the humoralists such as Galen, he had no use for drugs.cf.p. 49,note 5.

101About 4 oz., or one-third of a pint.

102The Empiricists,cf.Introduction, p.xiii.

103His ὄγκοι or molecules.

104He does not say “organized” or “living” body; inanimate things were also thought to possess “natures”;cf.p. 2,note 1.

105Carthamus tinctorius.

106Daphne Gnidium.

107Euphorbia acanthothamnos.

108Teucrium chamaedrys.

109Atractylis gummifera.

110On use of κενόωcf.p. 98,note 1.

111Empiricist physicians.

112Note that drugs also have “natures”;cf.p. 66,note 3, and pp.83-84.

113Pun here.

114Lit.physiology,i.e.nature-lore, almost our “Natural Philosophy”;cf.Introduction, p.xxvi.

115The ultimate particle of Epicurus was the ἄτομος or atom (lit. “non-divisible”), of Asclepiades, the ὄγκος or molecule. Asclepiades took his atomic theory from Epicurus, and he again from Democritus;cf.p. 49,note 5.

116Lit.Herculean stone.

117Lit.aetiology.

118Anadosis;cf.p. 62,note 1.

119cf.p.45.

120Thevis conservatrix et medicatrix Naturae.

121cf.p. 61,note 3. Thecrisisor resolution in fevers was observed to take place with a certain regularity; hence arose the doctrine of “critical days.”

122These were hypothetical spaces or channels between the atoms;cf.Introduction, p.xiv.

123He means the specific drawing power or faculty of the lodestone.

124cf.our modern “radium-emanations.”

125cf.Ehrlich’s hypothesis of “receptors” in explanation of the “affinities” of animal cells.

126i.e.from the point of view of the theory.

127cf.p. 69,note 2.

128That is to say, the two properties should go together in all cases—which they do not.

129Trygon pastinaca.

130cf.p. 66,note 3.

131The way that corn can attract moisture.

132Specific attraction of the “proper” quality;cf.p. 85,note 3.

133Theory of evaporation insufficient to account for it.cf.p. 104,note 1.

134Playful suggestion of free-will in the urine.

135Specific attraction,cf.p. 87,note 2.

136i.e.there would be no selective action.

137Nasal mucus was supposed to be the non-utilizable part of the nutriment conveyed to the brain,cf.p. 214,note 3.

138He means from its origin in the liver (i.e.in the three hepatic veins). His idea was that the upper division took nutriment to heart, lungs, head, etc., and the lower division to lower part of body. On the relation of right auricle to vena cava and right ventricle,cf.p. 321,notes 4and5.

139We arrive at our belief by excluding other possibilities.

140i.e.the mechanistic physicists.cf.pp.45-47.

141cf.p. 85,note 3.

142The subject ofanadosisis taken up in the next chapter.cf.also p. 62,note 1.

143On Erasistratusv.Introd. p.xii. His view that the stomach exerts noholké, or attraction, is dealt with more fully in Book III., chap.viii.

144i.e.the tissues.

145cf.p. 291.

146Peristalsismay be used here to translate Gk.peristolé, meaning the contraction and dilation of muscle-fibrescircularlyround a lumen,cf.p. 263,note 2.

147For a demonstration that this phenomenon is a conclusive proof neither ofperistolénor of real vitalattraction, but is found even in dead bodiesv.p.267.

148This was Erasistratus’s favourite principle, known in Latin as the “horror vacui” and in English as “Nature’s abhorrence of a vacuum,” although these terms are not an exact translation of the Greek. τὸ κενούμενον probably meansthe vacuum, not thematter evacuated, although Galen elsewhere uses κενόω in the latter (non-classical) sense,e.g.pp.67,215.Akolouthia is afollowing-up, asequence, almost aconsequence.

149v.p.123.

150cf.Book II.,chap. i.

151Vital factor necessary over and above the mechanical.

152cf.p. 119,note 2.

153pp.91, 93.

154i.e.the part below the liver;cf.p. 91,note 2.

155Renal veins.

156cf.p. 87,note 3.

157κοίλην: the usual reading is κοιλίαν, which would make it “from the region of the alimentary canal.”cf.p. 118,note 1.

158Not at an earlier stage, when it is still on its way from the alimentary canal to the liver.

159i.e.a renal vein.

160In a toast, the third cup was drunk to Zeus Sôtêr (the Saviour).

161An anatomist of the Alexandrian school.

162cf.nasal mucus, p. 90,note 1.

163“Sur l’Ensemble des Choses” (Daremberg).

164About twelve quarts. This is about five times as much as the average daily excretion, and could only be passed if a very large amount of wine were drunk.

165cf.p.51.

166Horror vacui. Note analogical reasoning;cf.p. 289,note 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.167Besides 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-calledepispastic168faculty, 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,169nor did she give it to the latter without also giving 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-canal170which areso 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 stomach171has the power of compressing the veins, as he himself supposed, and the veins again of contracting upon their contents and propelling them forwards.172For, apart from other considerations, noplethora173would 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 anindefinite 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;174there will not, however, be a plethora in any of the parts coming after the liver,175or, 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 thearterioid vein176to the lungs (for Erasistratus himself will have it that, owing to the membranous excrescences,177no 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 himself.

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 ofattraction. 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;178this idea is foolish in the case of blood, and impossible, nay, perfectly nonsensical, in the case of the urine.179

This, then, is one blunder made by those who dissociate themselves from the principle of attraction. Another is that which they make about thesecretion 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 arewider and those of the bile-ducts narrower,180then it is clear that this watery and serous superfluity,181too, 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 residue181passes through fine linen or lint 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!

Thus, every hypothesis ofchannels182as an explanation of natural functioning is perfect nonsense. For, if there were notan inborn facultygiven 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 ingenuity183and forethought; let us suppose they were steered only by material forces,184and not by any specialfaculties(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.185

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 needchannels, little or big, resting on an unproven hypothesis, for explaining the secretion of urine and bile, and the conception of somefavourable situation(in which point alone Erasistratus shows some common sense, since he does regard all the parts of the body ashaving 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,186and, 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 statuesimply 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 specialnature.187For 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,188while its activities it does not receive from its material, but it manifests them in connection therewith.

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 bloodit would remain inoperative and would not turn into anature. Therefore, in order that it may not perish, but may become anaturein 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.189And if we retain these two principles—that of proportionate attraction190and 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.191Here, 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.192Next, 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.193In fact,the alterative facultyhas now been discovered as well, although about this also Erasistratus has not written a word. And, thirdly theshaping194faculty 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,195you 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 housegrowswhen it is being built, or a basket when beingplaited, 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 stillbecomingattains its form is termed not growth but genesis. That whichis, grows, while that whichis not, becomes.

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]196of 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.197Further, it is at once the Hippocratic and the Aristotelian teaching that the parts which are being nourished receive that nourishment throughout their whole substance, and that, similarly, processes ofminglingandalterationinvolve the entire substance.198Moreover, that digestion is a species ofalteration—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 theinnate heat;199all 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 vain.

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 kidneys200—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 Porch201follow 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.202That 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 thequalitiesarebodies).203

Perhaps, however, they will maintain that it was in the matter oflogicthat 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 biliary204passages in the liver—for we have sufficiently discussed the kidneys—alleging [as the cause of bile-secretion] a favourable situation, the narrowness of vessels, andacommon spaceinto which the veins from the gateway [of the liver]205conduct 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 ofattraction, but he would thereby have been able to get rid of countless other disputed questions.

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 opening206at 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 ajunction207between the termination of the vein which is on the concave surface of the liver208and two other vascular terminations (that of the vessel on the convex surface of the liver209and 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,210and 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 ofanadosis.

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?

And if one looks carefully into the matter one will find that even Erasistratus’s reasoning on the subject ofnutrition, 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.211That is to say, whenblood 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 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?212For they do not also contain blood. One might obviously say that they draw their supply from the veins.213But 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 ofattraction. 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,214will 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 thenerve, being simple, attract its nourishment, as do the composite veins, by virtue of the tendencyof 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 withpsychic pneuma,215and 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.216For 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 itsimple; 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-calledinsensible transpirationof thephysicians 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 certaininharmonious elements. Once again, then, we must call Nature “inartistic”; for this necessarily follows the assumption of such elements.

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 theirelementsneed 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 aperceptible 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 calledprimaryandsimpleby 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 regardingnutrition. 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.217For, if we do not grant a certainunity of substance218to these simple structures as well, and if we arrive eventually at inharmonious and indivisible elements,219we 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 thepartsof the animal.220Now, 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 sheshapes 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,221nutritive, or, in a word, any artistic power; it is, by hypothesis, unimpressionable and untransformable,222whereas, as we have previously shown,223none 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 incapable of 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 thatsimple vesselof 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 whatway? For, when we were at this point before, we drew attention to the disagreement among the Erasistrateans,224and we showed that the nutrition of these simple vessels was impracticable 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.225

Let our argument, then, be transferred again to the doctrine which assumes thiselementary nerve226to 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 ordinaryperceptiblenerve, 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 theother the principle of the refilling of a vacuum227can 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.

Back to Index Next