318 Ciwicrian Si^ stein of Zoology, 



ation innumerable materials, and to individuals the means of 

 communication, which make all the species participate in the 

 experience of each individual ; so that knowledge may be in- 

 creased indefinitely through the lapse of future ages. This is 

 the distinctive character of the human understanding. 



The most perfect animals are infinitely below man in their 

 intellectual faculties; it is, nevertheless, certain that their 

 understanding leads them to perform actions of the same kind. 

 They move in consequence of the sensations they receive; 

 they are susceptible of durable affections ; they acquire a cer- 

 tain knowledge of things by experience, according to which 

 they conduct themselves, independently of actual pain and 

 pleasure, by the sole foresight of consequences. In a domestic 

 state, they feel their subordination, and know that the being 

 who punishes them is free to do so or not ; they assume a 

 supplicating air when they feel themselves culpable, or perceive 

 that their master is angry. They improve or deteriorate in 

 the society of man ; they are susceptible of emulation and jea- 

 lousy ; they have among themselves a natural language, which 

 is, indeed, only the expression cf their present sensations, but 

 man teaches them a much more complicated language, by 

 w^hich he makes them know his will, and compels them to 

 execute it. 



We perceive, indeed, in the superior animals, a certain 

 degree of reasoning, with all its effects, good or bad, which 

 appears to be nearly the same as that of infants before they 

 have learned to speak. In proportion as we descend to 

 animals more removed from man, the intellectual faculties 

 become weaker ; and, in the last classes, they finish, by being 

 reduced to signs of sensibility, which are sometimes equivocal, 

 that is, to certain feeble motions to escape pain. The degrees 

 between the two extremes are infinite. But there exists, in a 

 great number of animals, a faculty different from intelligence, 

 called instinct. This makes them perform certain actions, 

 necessary to the preservation of the species, but often alto- 

 gether foreign to the apparent wants of the individual ; and 

 often, also, extremely complicated. We cannot attribute these 

 actions to intelligence, without supposing a degree of foresight 

 and understanding infinitely superior to what we can admit in 

 the species that perform them. The actions performed by 

 instinct are not the effects of imitation, for the individuals that 

 execute them have often never seen them done by others ; they 

 bear no proportion to the common intelligence of the species, 

 but become more singular, more skilful, more disinterested, in 

 proportion as the animals belong to the less elevated classes, 

 and are, in other respects, most stupid. They are so much the 



