KANT AND EVOLUTION 47 



On this Kant remarks as follows : 



> 

 These ideas will not, indeed, cause the investigator of nature to shrink back 



from before them with a shudder, as from before a monstrosity M ( for there 



are many who have played with them for a time, though only to give them up 



as unprofitable). But the investigator will be frightened away from them upon 



a serious scrutiny, by a fear lest he be lured by them from the fertile fields of 



natural science to wander in the wilderness of metaphysics. And for my part 



I confess to a not unmanly terror in the presence of anything which sets the 



reason loose from its first and fundamental principles and permits it to rove 



in the boundless realms of imagination. 



Kanfs alarm, it is evident, was aroused by all three of the hypotheses 

 which he ascribed to Forster. But he particularly disapproved of any 

 attempt to inquire into the origin, the laws of genesis, of organisms in 

 general, or of the original " stock " from which any species is descended. 

 Such inquiries " lie beyond the province of any possible physical sci- 

 ence/' For science is competent to discover only relations of efficient 

 causation ; but organisms, being material systems " in which every part 

 is at once cause and effect of every other part," admit only of " a 

 teleological, not at all of a physico-mechanical, mode of explanation." 



6. The " ' KritiJc of Judgment." — The principal source of the belief 

 that Kant was an evolutionist in biology is a celebrated passage in the 

 "Kritik of Judgment'"' (1T90), § 80. This passage is, unfortunately, 

 usually quoted with its most important part — an appended foot-note — 

 omitted. That Kanfs true position may clearly appear (in so far as a 

 position which is involved in a scheme of elaborate self-contradictions 

 can ever be clear), it is necessary to cite the text here nearly in full: 



It is praiseworthy to go through the great creation of organized natures 

 with the aid of comparative anatomy, in order to see whether there may not 

 be in it something resembling a system, even in the principle of generation of 

 such beings. For otherwise ... we are obliged to give up in discouragement 

 all pretension to natural insight in this field. The agreement of so many species 

 of animals in a certain common plan which appears to underlie not only their 

 skeletal structure but also the arrangement of their other parts — so that, upon 

 the basis of an original outline of wonderful simplicity a great variety of spe- 

 cies could be produced merely by the shortening of one member and the length- 

 ening of another, the diminution of this part and the elaboration of that — all 

 this gives our minds a ray, though a feeble ray, of hope that something may 

 here really be done with the principle of the mechanism of nature — apart from 

 which there can be no natural science as such. This similarity of forms — so 

 great that, amidst all their diversity, they seem to have been produced according 

 to a common original type — gives force to the surmise of an actual relationship 

 between them, by virtue of their generation by one primal mother ( Urrmitter) 

 — through the gradual approximation of one animal species to another, from 

 that in which the principle of purposiveness seems best established, i. e., man, 



Schriften," TIL, p. 335, Forster emphatically asserts the immutability of "the 

 principal features of the primitive form (Urbild) of every species." 



34 Kant refers to a passage of Forsters in which these expressions are jest- 

 ingly used. But, as it happens, they were originally Kant's own expressions, 

 occurring in the review of Herder's " Ideen,*' already cited. 



