March 6, 1891.] 



SCIENCE. 



ence. When we remember how inveterate and how universal is 

 the bondage of all early thought to the subjective methods; 

 when we remember, that, for the best part of twenty centuries 

 after the birth of Aristotle, the intellect of Europe was still held 

 fast in the chains of that bondage; and when we remember that 

 even at the present time, with all the advantages of a long and pain- 

 ful experience, we find it so extremely difficult to escape it, — 

 when we remember these things, we can only marvel at the scien- 

 tific instinct of this man who, although nurtured in the school of 

 Plato, was able to see — darkly, it may be, and, as it were, in the 

 glass of future things, but still was able to see — that the true 

 method of science is the method of observation and experiment. 

 " Men who desire to learn," he said, " must first learn to doubt, 

 for science is only the solution of doubts ; " and it is not possible 

 more concisely to state the intellectual duty of scepticism, or the 

 paramount necessity of proof, which thousands of years of 

 wasted toil have now enabled all intelligent men more or less to 

 realize. 



Nevertheless, as I have said, the vision of scientific method 

 which Aristotle had' was a vision of that which is only seen in 

 part : the image of the great truth which he perceived was largely 

 distorted by passing through the medium of pre-existing thought. 

 Consequently, of late years a great deal of discussion has taken 

 place on the subject of Aristotle's method. On the one hand, it 

 is maintained that he is entitled to the place which is usually 

 assigned to Bacon as the father of the inductive methods ; while, 

 on the other hand, it is maintained that in respect of method he 

 did not make any considerable advance upon his predecessors. 

 In my opinion, a just estimate lies between these two extremes. 

 Take, for example, the following passages from his writings: — 



" We must not accept a general principle from logic only, but 

 must prove its application to each fact, for it is in facts that we 

 must seek general principles, and these must always accord with 

 facts." 



" The reason why men do not sufficiently attend to the facts is 

 their want of experience. Hence those accustomed to physical 

 inquiry are more competent to lay down the principles which have 

 an extensive application; whereas others who have been accus- 

 tomed to many assumptions without the apposition of reality, 

 easily lay down principles because they take few things into con- 

 sideration. It is not difficult to distinguish between those who 

 argue from tacts and those who argue from notions." 



Many similar passages to the same effect might be quoted, and 

 it is evident that the true method of inductive research could not 

 well have iis leading principles more clearly enunciated ; and to 

 say this much is in itself enough to place Aristotle in the foremost 

 rank among the scientific intellects of the world. But it would 

 be unreasonable to expect that this gi-eat herald of scientiSc 

 method should have been able, with any powers of intellect, to 

 have entirely emancipated himself from the whole system of pre- 

 vious thought; or in the course of a single lifetime to have fully 

 learned the great lesson of method which has only been taught by 

 the best experience of more than twenty centuries after his death. 

 Accordingly, we find that, although he clearly divined the true 

 principles of research, he not unfrequently fell short in his appli- 

 cation of those principles to practice. In particular, he had no 

 adequate idea of the importance of verifying each step of a re- 

 search, or each statement of an exposition ; and therefore it is 

 painfully often that his own words just quoted admit of being 

 turned against himself, — "It is easy to distinguish between those 

 who argue from facts and those who argue from notions." To 

 give only a single example, he says that if a woman who has 

 scarlet-fever looks at herself in a mirror, the mirror will become 

 suffused with a bloody mist, which, if the mirror be new, can only 

 be rubbed off with difficulty. Now, instead of proceeding to 

 verify this old wife's tale, he attempts to explain the alleged fact 

 by a rambling assemblage of absurd "notions." And numerous 

 other instances might be given to the same effect. Nevertheless, 

 upon the whole, or as a general rule, in his thought and language, 

 in his mode of conceiving and grappling with problems of a sci- 

 entific kind, in the importance which he assigns to the smallest 

 facts, and in the general cast of reasoning which he employs, 

 Aristotle resembles, much more closely than any other philoso- 



129 



pher of like antiquity, a scientific investigator of the present 

 day. 



Thus, in seeking to form a just estimate of Aristotle's work in 

 natural history, we must be careful, on the one hand, to avoid the 

 extravagant praise which has been lavished upon him, even by 

 such authorities as Cuvier, De Blainville, Isidore St. Hilairc, etc. ; 

 and, on the other hand, we must no less carefully avoid the un- 

 fairness of contrasting his working methods with those which have 

 now become habitual. 



In proceeding to consider the extraordinary labors of this ex- 

 traordinary man, in so far as they were concerned with natural 

 history, I may begin by enumerating, but without waiting to 

 name, the species of animals with which we know that he was 

 acquainted. From his works on natural history, then, we find 

 that he mentions at least 70 species of mammals, 150 of birds, 20 

 of reptiles, 116 of fish, 84 of articulata, and about 40 of lower 

 forms, making close upon 500 species in all. That he was accus- 

 tomed from his earliest boyhood to the anatomical study of animal 

 forms, we may infer from the fact of his father having been a 

 physician of eminence, and an Asclepiad; for, according to Galen, 

 it was the custom of the Asclepiads to constitute dissection part 

 of the education of their children. Therefore, as Aristotle's boy- 

 hood was passed upon the seacoast, it is probable that from a 

 very early age his studies were directed to the anatomy and 

 physiology of marine animals. But, of course, it must not be 

 concluded from this that the dissections then practised were com- 

 parable with what we understand by dissections at the present 

 time. We find abundant evidence in the writings of Aristotle 

 himself that the only kind of anatomy then studied was anatomy 

 of the grosser kind, or such as might be prosecuted with a carv- 

 ing-knife as distinguished from a scalpel. 



We generally hear it said that as a natm-alist Aristotle was a 

 teleologist, or a believer in the doctrine of design as manifested ia 

 living things: therefore I should like to begin by making it clear 

 how far this statement is true; for, unquestionably, when such 

 an intellect as that of Aristotle is at work upon this important 

 question, it behooves us to consider exactly what it was that he 

 concluded. 



Now, I do not dispute — indeed, it would be quite impossible to 

 do so — that Aristotle was a teleologist, in the sense of being in 

 every case antecedently convinced that organic structures are 

 adapted to the performance of definite functions, and that the 

 organism as a whole is adapted to the conditions of its existence. 

 Thus, for example, he very clearly says, " As every instrument 

 subserves some particular end, that is to say, some special func- 

 tion, so the whole body must be destined to minister to some ple- 

 nary sphere of action; just as the saw is made for sawing, — this 

 being its function, — and not sawing for the saw." 



But in any other sense than this of recognizing adaptation in 

 Nature, I do not think there is evidence of Aristotle having been 

 a teleologist. In his "Metaphysics" he asks the question whether 

 the principle of order and excellence in Nature is a self-existing 

 principle inherent from all eternity in Nature herself; or whether 

 it is like the discipline of an army, apparently inherent, but reaUy 

 due to a general in the background. Aristotle, I say, asks this 

 question; but he gives no answer. Similarly, in his "Natural 

 History," he simply takes the facts of order and adaptation as 

 facts of observation: and therefore in biology I do not think that 

 Aristotle can be justly credited with teleology in any other sense 

 than a modern Darwinist can be so credited ; that is to say, he is 

 a believer in adaptation, or final end, but leaves in abeyance the 

 question of design, or final cause. The only respect in which he 

 differs from a modprn Darwinist, although even here the school 

 of Wallace and Weismann agree with him, is in holding that 

 adaptation must be present in all cases, even where the adaptation 

 is not apparent. In the case of rudimentary organs, he is puzzled 

 to account for structures apparently aimless, and therefore he in- 

 vents what we may term an imaginary aim by saying that Nature 

 has supplied these structures as " tokens," whei-eby to sustain her 

 unity of plan. This idea was prominently revived in moilern 

 pre- Darwinian times ; but in the present connection it is enough 

 to observe that here, as elsewhere, Aristotle personifies Nature as 

 a designing or contriving agency, having the attainment of order 



