492 HISTOEY OF PHYSIOLOGY. 



observe, that he is allowed by all to have established, on an indestructi- 

 ble basis, many of the most important generalizations which zoology 

 now contains; and the principal defect which his critics have pointed 

 out, has been, that he did not generalize still more widely and boldly. 

 It appears, therefore, that he cannot but be placed among the great 

 discoverers in the studies which he pursued ; and this being the case, 

 those who look with pleasure on the tendency of the thoughts of the 

 greatest men to an Intelligence far higher than their own, must be 

 gratified to find that he was an example of this tendency ; and that 

 the acknowledgement of a creative purpose, as well as a creative power, 

 not only entered into his belief, but made an indispensable and promi- 

 nent part of his philosophy. 



Sect. 3. Establishment and Application of the Principle of lie Con- 

 ditions of Existence of Animals. Cuvier. 



WE have now to describe more in detail the doctrine which Cuvier 

 maintained in opposition to such opinions as we have been speaking of; 

 and which, in his way of applying it, we look upon as a material 

 advance in physiological knowledge, and therefore give to it a distinct 

 place in our history. " Zoology has," he says, 19 in the outset of his 

 Regne Animal, " a principle of reasoning which is peculiar to it, and 

 which, it employs with advantage on many occasions : this is the prin- 

 ciple of the Conditions of Existence, vulgarly the principle of Final 

 Causes. As nothing can exist if it do not combine all the conditions 

 which render its existence possible, the different parts of each being 

 must be co-ordinated in such a manner as to render the total being 

 possible, not only in itself, but in its relations to those which surround 

 it ; and the analysis of these conditions often leads to general laws, as 

 clearly demonstrated as those which result from calculation or from 

 experience." 



This is the enunciation of his leading principle in general terms. 

 To our ascribing it to him, some may object on the ground of its being 

 self-evident in its nature, 20 and having been very anciently applied. 

 But to this we reply, that the principle must be considered as a real 

 discovery in the hands of him who first shows how to make it an in- 

 strument of other discoveries. It is true, in other oases as well as in 

 this, that some vague apprehension, of true general principles, such as a 



19 Rtgne An. p. 6. 20 Swainson, Study of Nat. Hint. p. 85. 



