172 Instinct, 



plest form, supplements structure and function ; 

 and that Instinct varies in every animal, as the 

 structure and function of his organs change. These 

 three elements then being the same in thousand? 

 of individuals of the same species, we shall have a 

 constant resultant in each one of them, unless ex- 

 ternal circumstances come in as a disturbing ele- 

 ment. These three elements are so strong in their 

 combined action, in every animal, that they shape 

 his life, — experience is not able to turn him from 

 the course along which they impel him. Experi- 

 ence may do much for the higher animals, — it may 

 keep them from danger, add to their enjoyment of 

 life and improve them in many ways ; but it can 

 never turn them from that course, along which the 

 functions of organs and the original impulse and 

 guidance of Instinct, carry them. 



We see nothing in animals of the same species, 

 that renders them unlike each other in followino- 

 the impulses arising from the function of their or- 

 gans. — The animal seems, in this respect, to be pas- 

 sive in the formation of its controlling impulses ; 

 and he follows the great impulses of his nature, 

 freely, and without consideration of the remote 

 consequences. That nature of the animal, which 

 leads him to take into consideration only the pres- 

 ent, the surrounding circumstances for the moment, 

 will secure a uniformity not to be expected in man, 

 who brings in to modify every activity, the memo- 

 ry of the past, the accumulated experience of men 

 in all ages, and the expectation of the future, with 

 all its uncertainties, which never can affect an ani- 



