382 THE POPULAR SCIENCE MONTHLY 



moment. The forms or ideas of a Plato or an Aristotle correspond to privileged 

 or salient moments in the history of things — the very same moments, gen- 

 erally speaking, that have been fixed by language. They are supposed, like 

 the infancy and old age of a living being, to characterize and express the 

 quintessence of a period, all the remainder of which is filled with the transition 

 from one state to another, and is, therefore, devoid of interest in itself. 

 Consider, for example, the falling of a body. It was thought to be a sufiicient 

 account of the fact when it had been characterized summarily as a movement 

 downward, a tendency towards a center, the natural movement of a body, 

 which, after being separated from the earth to which it belongs, returns 

 again to its original position. Therefore, the final or culminating point 

 (TeAof, aKfir/) of a process is singled out and is erected into an essential 

 moment, and science is satisfied with this moment, which language has seized 

 upon for the purpose of expressing the ensemble of the fact. In the physics 

 of Aristotle, the movement of a body hurled through space, or freely falling, 

 is defined by concepts of above and below, of spontaneous and enforced dis- 

 placement, of proper and improper position. But Gallilei believed that there 

 was no essential moment, no privileged instant; in his opinion one should 

 be able to give an account of a falling body at any moment in its course, 

 for that is the true science of gravitation which determines the position of a 

 body in space at any instant of time. For this purpose we, of course, need 

 more precise symbols than those of language.'' 



To Aristotle we may also turn for a biological illustration of the 

 differences between ancient and modern scientific observation. Accord- 

 ing to his conception, the type or privileged moment of humanity is 

 represented by the adult male individual, with reference to whom youth 

 and age are merely incipient and declining stages respectively, and 

 woman is merely an abortive attempt on the part of nature to produce a 

 man. Contrast with this our present biological conception of the sexes 

 .and the ontogeny of the human species ! 



It must be admitted that the tendency of modern science is in the 

 •direction of much greater refinement on the ancient method, a tendency 

 to scrutinize more humbly and more closely, and hence, to multiply 

 indefinitely the observed moments and aspects. I, therefore, do not 

 use the term " ancient " in the sense of " no longer existing," since the 

 tendency thus designated is still constantly manifested in all our ordi- 

 nary thinking. To observe and retain only the privileged moments 

 and aspects of things is for very many purposes eminently practical, 

 but it has its disadvantages, for the more such moments of an 

 object are accentuated or exalted, the more insignificant or debased 

 become its other aspects. Such emphasis may be highly artistic, but 

 it is contrary to the spirit of modern science. Indeed, much of the lack 

 of sympathy that exists between men of extremely artistic and extremely 

 scientific temperament is due to this difference of instinctive attitude 

 towards the world of phenomena. 



It is well known that in their development the biological have 



' " L'Evolution Crgatriee," 4th edition, 1908, pp. 357, 358. 



