THE DOCTRINE OF FINAL CAUSES. 493 



priori considerations can supply, has long preceded the knowledge of 

 them as real and verified laws. In such a way it was seen, before 

 Newton, that the motions of the planets must result from attraction ; 

 and so, before Dufay and Franklin, it was held that electrical actions 

 must result from a fluid. Cuvier's merit consisted, not in seeing that 

 an animal cannot exist without combining all the conditions of its exist- 

 ence; but in perceiving that this truth may be taken as a guide in our 

 researches concerning animals ; that the mode of their existence may 

 be collected from one part of their structure, and then applied to inter- 

 pret or detect another part. He went on the supposition not only that ani- 

 mal forms have some plan, some purpose, but that they have an intelligible 

 plan, a discoverable purpose. He proceeded in his investigations like 

 the decipherer of a manuscript, who makes out his alphabet from one 

 part of the context, and then applies it to read the rest. The proof 

 that his principle was something very different from an identical pro- 

 position, is to be found in the fact, that it enabled him to understand 

 and arrange the structures of animals with unprecedented* clearness and 

 completeness of order ; and to restore the forms of the extinct animals 

 which are found in the rocks of the earth, in a manner which' has 

 been universally assented to as irresistibly convincing. These results 

 cannot flow from a trifling or barren principle ; and they show us that if 

 we are disposed to form such a judgment of Cuvier's doctrine, it must 

 be because we do not fully apprehend its import. 



To illustrate this, we need only quote the statement which he makes, 

 and the uses to which he applies it. Thus in the Introduction to his 

 great work on Fossil Remains he says, " Every organized being forms 

 an entire system of its own, all the parts of which mutually correspond, 

 and concur to produce a certain definite purpose by reciprocal reaction, 

 or by combining to the same end. Hence none of these separate parts 

 can change their forms without a corresponding change in the other 

 parts of the same animal ; and consequently each of these parts, taken 

 separately, indicates all the other parts to which it has belonged. Thus, 

 if the viscera of an animal are so organized as only to be fitted for the 

 digestion of recent flesh, it is also requisite that the jaws should be so con- 

 structed as to fit them for devouring prey; the claws must be constructed 

 for seizing it and tearing it to pieces ; the teeth for cutting and dividing 

 its flesh ; the entire system of the limbs or organs of motion for pur- 

 suing and overtaking it ; and the organs of sense for discovering it at 

 a distance. Nature must also have endowed the brain of the animal 

 with instincts sufficient for concealing itself, and for laying plans to 



