INTRODUCTION. 13 



to generation. This is the only sense in which the word 

 can be now used by educated people ; in this sense, clear 

 manifestations of instinct play a very important role in 

 man's life, as in that of animals, although its influence is 

 stronger and more apparent in the latter. It has, therefore, 

 always aroused man's wonder, and led him, since he could 

 not explain its origin, to the useless and foolish notion of an 

 "instinct;" just in the same way, our ancestors, as they 

 could not explain the rising of water against gravity into an 

 exhausted receiver, ascribed it to nature's horror vacui, 

 abhorrence of a vacuum, or as uneducated and thoughtless 

 people now refer the origin of life to a special " vital 

 force." That nothing is made clearer by such subterfuges, 

 but that the whole question is made darker by the encourage- 

 ment thus given to obscurity and mental sloth, must be 

 seen by all. Shakspere jeers very bitterly at instinct when 

 he makes Falstaff say in excuse for his senseless cowardice : 

 " Instinct is a great matter ; I was a coward on instinct." 



Man, indeed, by a careful study of animal intelligence, 

 by experience and observation, is led step by step to note 

 manifestations and facts, and thus the conception of instinct 

 is shown to be inconsistent, and is shattered in pieces ; that 

 is, if instinct be used in the generally accepted sense of an 

 inborn, inherited, unchangeable and therefore never erring 

 impulse of nature, bestowed for the preservation and pro- 

 pagation of animals, the manifestations of which are uncon- 

 scious and purposeless. Accurate study shows that the 

 greater part of the actions attributed to instinct may be 

 understood in a very different an r l more natural way, as 

 arising sometimes from true consideration and free choice, 

 sometimes from experience, instruction and training, from 

 practice or imitation, sometimes from a special development 

 of a sense, as smell, sometimes from habit and organi- 

 sation, from reflection, etc., etc. For instance, when the 

 caterpillar uses the thread given him by nature for spinning 

 his cocoon, to let himself down from a tree and to escape 

 thereby from his pursuer; when caterpillars, shut up in 

 cases, tear off and use for their chrysalis the paper with 

 which these cases are lined ; when the toad eats a great 

 quantity of ants which it cannot digest, because they suit 

 its taste, although it knows that it is thereby drawing upon 

 itself pain and sickness ; when bees greedily eat honey 



