TELEOLOGY AND CORRELATION 35 



using teleology as a regulative principle, in Kant's sense 

 of the word. Cuvier was indeed a teleologist after the 

 fashion of Kant, and there can be no doubt that he 

 was influenced, at least in the exposition of his ideas, by 

 Kant's Kritik dcr Urtheilskraft, which appeared ten years 

 before the publication of the Lccons d' Anatomic Comparee. 

 Teleology in Kant's sense is and will always be a necessa-ry 

 postulate of biology. It does not supply an explanation of 

 organic forms and activities, but without it one cannot even 

 begin to understand living things. Adaptedness is the most 

 general fact of life, and innumerable lesser facts can be grouped 

 as particular cases of it, can be, so far, understood. 



Cuvier's famous principle of correlation, the corner-stone 

 of his work, is simply the practical application to the facts of 

 structure of the principle of functional adaptedness. By the 

 principle of correlation, from one part of an animal, given 

 sufficient knowledge of the structure of its like, you can 

 in a general way construct the whole. " This must necessarily 

 be so : for all the organs of an animal form a single system, 

 the parts of which hang together, and act and re-act upon 

 one another ; and no modifications can appear in one part 

 without bringing about corresponding modifications in all 

 the rest." * The logical basis of the principle is sound. 

 The functions of the parts are all intimately bound up with 

 one another, and one function cannot vary without bring- 

 ing in its train corresponding modifications in the others. 

 Structure and function are bound up together ; every modifi- 

 cation of a function entails therefore the modification of 

 an organ. Hence from the shape of one organ you can infer 

 the shape of the other organs if you have sufficiently 

 extensive empirical knowledge of functions, and of the 

 relation of structure to function in each kind of organ. Given 

 an alimentary canal capable of digesting only flesh, and 

 possessing therefore a certain form, you know that the other 

 functions must be adapted to this particular function of the 

 alimentary canal. The animal must have keen sight, fine 

 smell, speed, agility, and strength in paws and jaws. These par- 

 ticular functions must have correspondingly modified organs, 



1 Histoire des Progrcs des Sciences nalurelles depuis 1789, i., p. 310, 

 1826. 



