I] OF ULTIMATE CAUSATION 9 



with what the schoohnen called a ratio cognoscendi, though the true 

 ratio efflciendi is still enwrapped in many mysteries. And so handled, 

 the quest of physical causes merges with another great Aristotelian 

 theme — the search for relations between things apparently dis- 

 connected, and for "similitude in things to common view unlike*." 

 Newton did not shew the cause of the apple falling, but he shewed 

 a simihtude ("the more to increase our wonder, with an apple") 

 between the apple and the starsf. By doing so he turned old facts 

 into new knowledge ; and was well content if he could bring diverse 

 phenomena under "two or three Principles of Motion" even "though 

 the Causes of these Principles were not yet discovered". 



Moreover, the naturalist and the physicist will continue to speak 

 of "causes", just as of old, though it may be with some mental 

 reservations : for, as a French philosopher said in a kindred difficulty : 

 "ce sont la des manieres de s'exprimer, et si elles sont interdites 

 il faut renoncer a parler de ces choses." 



The search for differences or fundamental contrasts between the 

 phenomena of organic and inorganic, of animate and inanimate, 

 things,, has occupied many men's minds, while the search for com- 

 munity of principles or essential simihtudes has been pursued by 

 few; and the contrasts are apt to loom too large, great though they 

 may be. M. Dunan, discussing the Probleme de la Viel, in an essay 

 which M. Bergson greatly commends, declares that "les lois physico- 

 chimiques sont aveugles et brutales ; la ou elles regnent seules, au 

 lieu d'un ordre et d'un concert, il ne pent y avoir qu'incoherence et 

 chaos." But the physicist proclaims aloud that the physical 

 phenomena which meet us by the way have their forms not less 

 beautiful and scarce less varied than those which move us to admira- 



nous sont point connues; mais elles sont assujetties a des lois simples et eonstantes, 

 que Ton peut decouvrir par I'observation, et dont I'etude est I'objet de la philosophie 

 naturelle." 



* "Plurimum amo analogias, fidelissimos meos magistros, omnium Naturae 

 arcanorum conscios," said Kepler; and Perrin speaks with admiration, in Les 

 Atonies, of men like Galileo and Carnot, who "possessed the power of perceiving 

 analogies to an extraordinary degree." Hure^e declared, and Mill said much the 

 same thing, that all reasoning whatsoever depends on resemblance or analogy, 

 and the power to recognise it. Comparative anatomy (as Vicq d'Azyr first called 

 it), or comparative physics (to use a phrase of Mach's), are particular instances of 

 a sustained search for analogy or similitude. 



t As for Newton's apple, see De Morgan, in Notes and Queries (2), vi, p. 169, 1858. 



I Revue Philosophique, xxxiii, 1892. 



