332 LAMARCK, HIS LIFE AND WORK 



system,* have perceptions of objects which affect 

 them, and seem to have memory of them when they 

 are repeated. Yet they can vary their actions and 

 change their habits, though they do not possess the 

 organ whose acts could give them the means. 



" On the Instincts of Animals. 



" We define instinct as the sum {ensemble) of the 

 decisions {de'terminaiions) of animals in their actions; 

 and, indeed, some have thought that these determi- 

 nations were the product of a rational choice, and 

 consequently the fruit of experience. Others, says 

 Cabanis, may think with the observers of all ages that 

 several of these decisions should not be ascribed to 

 any kind of reasoning, and that, without ceasing as 

 for that to have their source in physical sensibility, 

 they are most often formed without the will of the 

 individuals able to have any other part than in better 

 directing the execution. It should be added, without 

 the will having any part in it ; for when it does not 

 act, it does not, of course, direct the execution. 



" If it had been considered that all the animals 

 which enjoy the power of sensation have their inner 

 feeling susceptible of being aroused by their needs, 

 and that the movements of their nervous fluids, which 

 result from these emotions, are constantly directed 

 by this inner sentiment .and by habits, then it has 

 been felt that in all the animals deprived of intelli- 

 gence all the decisions of action can never be the re- 

 sult of a rational choice, of judgment, of profitable 

 experience — in a word, of will — but that they are 

 subjected to needs which certain sensations excite, 

 and which awaken the inclinations which urge them 

 on. 



" In the animals even which enjoy the power of 



* Rather a strange view to take, as the brain of insects is now 

 kaown to be nearly as complex as that of mammals. 



