216 ANIMAL AUTOMATISM y 



consciousness, leaves a more or less persistent 

 structural modification, through which the same 

 molecular change may be regenerated by other 

 agencies than the cause which first produced it. 



Thus far, the prepositions respecting the physio- 

 logy of the nervous system which are stated by 

 Descartes have simply been more clearly defined, 

 more fully illustrated, and, for the most part, 

 demonstrated, by modern physiological research. 

 But there remains a doctrine to which Descartes 

 attached great weight, so that full acceptance of 

 it became a sort of note of a thoroughgoing 

 Cartesian, but which, nevertheless, is so opposed to 

 ordinary prepossessions that it attained more 

 general notoriety, and gave rise to more discussion, 

 than almost any other Cartesian hypothesis. It 

 is the doctrine that brute animals are mere 

 machines or automata, devoid not only of reason, 

 but of any kind of consciousness, which is stated 

 briefly in the " Discours de la Methode," and more 

 fully in the "Reponses aux Quatri ernes Objections," 

 and in the correspondence with Henry More. 1 



The process of reasoning by which Descartes 

 arrived at this startling conclusion is well shown 

 in the following passage of the " Reponses : " 



" But as regards the souls of beasts, although this is not the 

 place for considering them, and though, without a general 



1 Espouse de M. Descartes A M. Morns. 1649. (Euvres, 

 tome x. p. 204. "Mais le plus grand de tous les prejugi's qne 

 nous ayons retenus de not re onfani-e, est crlui de croire (jue les 

 ln-tcs pcnst-nt," etc 



