362 FALLACIES. 



ce qu'on n'entend pas; mais j'ajoute qu'on a droit de 

 nier (au moins dans 1'ordre naturel) ce qui absolument 

 n'est point intelligible ni explicable. Je soutiens 

 aussi . . . qu'enfin la conception des creatures n'est 

 pas la mesure du pouvoir de Dieu, mais que leur con- 

 ceptivite, ou force de concevoir, est la mesure du 

 pouvoir de la nature, tout ce qui est conforme a 1'ordre 

 naturel pouvant tre concu ou entendu par quelque 

 creature." 



Not content with assuming that nothing can be 

 true which we are unable to conceive, philosophers 

 have frequently given a still further extension to the 

 doctrine,, and contended that, even of things not alto- 

 gether inconceivable, that which we can conceive with 

 the greatest ease is likeliest to be true. It was long 

 an admitted axiom, and is not yet entirely discredited, 

 that " nature always acts by the simplest means," i. e. 

 by those which are most easily conceivable. A large 

 proportion of all the errors ever committed in the 

 investigation of the laws of nature, have arisen from 

 the assumption that the most familiar explanation or 

 hypothesis must be the truest. One of the most 

 instructive facts in scientific history is the pertinacity 

 with which the human mind clung to the belief that 

 the heavenly bodies must move in circles, or be 

 carried round by the revolution of spheres; merely 

 because those were in themselves the simplest suppo- 

 sitions: although, to make them accord with the facts 

 which were ever contradicting them more and more, 

 it became necessary to add sphere to sphere and circle 

 to circle, until the original simplicity was converted 

 into almost inextricable complication. 



4. We pass to another a priori fallacy or natural 

 prejudice, allied to the former, and originating as that 



