Makch 6, 1 89 1.] 



SCIENCE. 



131 



cnosidered that position the noblest, and repeatedly argues that 

 on this account it must be the seat of mind. But over and above 

 this mystical, not to say childish, reason, I think he must have 

 Ihad another : for, seeing that the error is a very general one in 

 «arly philosophical thought, — we find it running through the 

 Psalms, and it is still conventionally retained by all poetic writers, — 

 I think we must look for some more evident reason than that of 

 mere position to account for it ; and this reason I take to be the 

 perceptible influence on the heart-beat which is caused by emo- 

 tions of various kinds. Furthermore, Aristotle expressly assigns 

 the following as another of his reasons: "In the embryo the 

 heart appears in motion before all other parts, as if it were a living 

 animal, and as if it were the beginning of all animals that have 

 blood." 



Turning, now, for a moment to Aristotle's still more detailed 

 discoveries in comparative anatomy and physiology, his most re- 

 markable researches are, I think, those on the Cetacea, Crustacea, 

 and Cephalopoda. Here the amount of minute and accurate ob- 

 servation which he displayed is truly astonishing, and in some 

 ■cases his statements on important matters of fact have only been 

 verified in our own century; such, for instance, as the peculiar 

 mode of propagation which has now been re-discovered in some 

 of the Cephalopoda.' He also knew the anomalous fact that in 

 these animals the vitellus is joined to the mouth of the embryo; 

 that in certain species of cartilaginous flsh the embryo is attached 

 to its parent by the intervention of a placenta-like structure ; and, 

 in short, detailed so many anatomical discoveries, both as regards 

 the vertebrata and invertebrata, that a separate article would be 

 required to make them intelligible to a general reader. In this 

 connection, therefore, I will only again insist upon the enormous 

 difference between Aristotle and the great majority of his illus- 

 trious countrymen in respect of method. Unless it can be shown 

 that an ancient writer has been led to anticipate the results of 

 modern discovery by the legitimate use of inductive methods, he 

 deserves no more credit for his guesses when they happen to have 

 been right than he does when they happen to have been wrong. 

 This, however, is a consideration which we are apt to neglect. 

 When we find that an old philosopher has made a statement which 

 science has afterwards shown to be true, we are apt to regard the 

 fact as proof of remarkable scientific insight; whereas, when we 

 investigate the reasonings which led him to propound the state- 

 ment, we usually find that they are of a puerile nature, and only 

 happened to hit the truth, as it were, by accident. Among a 

 number of guesses made at random and in ignorance, a certain 

 percentage may well prove right; but, under these circumstances, 

 the man who happens to make a correct guess deserves no more 

 credit than he who happens to have made an erroneous one. In- 

 deed, he may deserve even less credit. For instance : when the 

 Pythagoreans, on a basis of various mystical and erroneous specu- 

 lations, propounded a kind of dim adumbration of the heliocentric 

 theory, far from deserving any credit for superior sagacity at the 

 bands of modern science, they merit condemnation for their ex- 

 travagant tlieorizing and unguarded belief. In their time, what- 

 ever evidence there was lay on the side of the then prevalent view 

 that the sun moves round the earth : therefore, when, without 

 adducing any counter-evidence of a scientific kind, they affirmed 

 that the earth moved round the sun, they were merely displaying 

 the spirit of what the Yankees call " pure cussedness; " that is to 

 say, they were shutting tlieir eyes to the only evidence which was 

 available, and showing their own obstinacy by propounding a 

 •directly opposite view. The sound maxim in science is, that he 

 •discovers wlio proves; and this is a maxim which many classical 

 scholars would do well to remember when writing about the soi- 

 •entific speculations of the early Greeks. 



Now, I have made these remarks in order again to emphasize 

 the almost unique position which Aristotle holds among his con- 

 temporaries in this respect. Instead of giving his fanc}' free 

 rein upon "the high priori road," he patiently plods the way 

 of detailed i-esearch; and, when he proceeds to generalize, 

 lie does so as far as possible upon the basis of his inductive 

 .experience. 



^ Lewes, however, denies that the evidence i3 sufficient to show that Aris- 

 totle fcnew this. 



Coming, now, to his generalizations, it was a true philosophical 

 insight which enabled Aristotle to perceive in organic nature an 

 ascending complexity of organization from the vegetable kingdom 

 up to man. Instead. of the three kingdoms of Nature, which were 

 afterwards formulated by the alchemists, and which in general 

 parlance we still continue to preserve, namely, the mineral, vege- 

 table, and animal — instead of these three kingdoms, Aristotle 

 adopted the much more philosophical classification of Nature into 

 two divisions, the organic and the inorganic, or the living and 

 the not-living. Nevertlieless he fell into the error — which was, 

 indeed, almost unavoidable in his time — of supposing that there 

 is a natural and a daily passage of the one into the other. How- 

 ever, he again shows his philosophical insight where he points out 

 the leading distinctions between plants and animals, the former 

 manifesting life in the phenomena of nutrition alone, including 

 germination, growth, repair, and reproduction; while the latter, 

 besides these, exhibit also the phenomena of sensation, volition, 

 and spontaneous movement. He was not so fortunate in his 

 attempts at drawing the boundary-lines between plants and ani- 

 mals : for while he correctly guessed, from erroneous observation, 

 that sponges should be classified as animals, he decided in favor 

 of placing the hydroid polyps among the plants ; and he appears 

 to have classified certain testaceous mollusks in the same cate- 

 gory. Man, of course, he places at the head of the animal king- 

 dom, and shows a profound penetration in drawing the true psy- 

 chological distinction between him and the lower animals ; namely, 

 that animals only know particular truths, never generalize, or 

 form abstract ideas 



His conception of life was more in accordance with that of 

 modern science than that of any of the other conceptions which 

 have been formed of it either in ancient times or the middle ages, 

 for he seems clearly to have perceived the error of regarding the 

 "vital principle" otherwise than as an abstraction of our own 

 making. Life and mind, in his view, were abstractions pertain- 

 ing to organisms, just in the same way as weight and heat are 

 abstractions pertaining to inanimate objects. For convenience of 

 expression, or even for purposes of research, it may be desirable 

 to speak of weight and heat as independent entities : but we know 

 that they cannot exist apart from material objects ; that they are 

 what we term qualities, and not themselves objects. And so with 

 life and mind : they are regarded by Aristotle as qualities — or, as 

 we should now say, functions — of organisms. And here we 

 must remember that the whole course of previous speculation on 

 such matters proceeded on the assumption that the vital principle 

 was an independent entity superadded to organisms, serving to 

 animate them as long as it was united to them, leaving them to 

 death and decay as soon as it was withdrawn from them, and 

 even then being itself able to survive as a disembodied spirit, en- 

 joying its conscious existence apart from all material conditions. 

 Thus it was that the creations of early thought peopled the world 

 with ghosts and spirits more numerously than Nature had sup- 

 plied it with living organisms. Now, Aristotle boldly broke away 

 from this fundamental assumption of the vital principle as an 

 independent and superadded entity. In the phenomena of life 

 and mind he saw merely the functions of organism : he assigned 

 to them both a physical basis, and clearly perceived that for any 

 fruitful study of either we must have recourse to the methods of 

 physiology. 



The scientific genius which could have enabled a man in those 

 days thus to have anticipated the temper of modern thought, ap- 

 pears to me entitled to our highest veneration. Here, perhaps 

 more than anywhere else, he showed his instinctive appreciation 

 of the objective methods ; and here it is that the longest time 

 has been taken for mankind to awaken to the truth of his appre- 

 ciation. 



In subsequent centuries, when European thought drifted away 

 from science into theology, the question was long and warmly 

 debated whether or not Aristotle believed in the immortality of 

 the soul. The truth of the matter is that his deliverances upon 

 this question are more scarce than clear. The following brief 

 passage, however, appears to show that he regarded the thinking 

 principle, as distinguished from the animal soul, to be virtually 

 independent of the corporeal organization: "Only the intellect 



