THE DARWINIAN THEORY OF INSTINCT. 587 



needs of the animal presenting it, the perfection is to be attributed to 

 a God-given faculty of wisdom. This, I say, is the oldest theory of 

 instinct, and I may add that until within the past twenty-five years 

 it has been the only theory of instinct. I think, therefore, I ought 

 to begin by explaining that this venerable and time-honored theory 

 is a purely theological explanation of the ultimate source of instinct, 

 and therefore can not be affected by any scientific theory as to the 

 proximate causes. It is with such a theory alone that we shall here 

 be concerned. 



" When giants build, men must bring the stones." For the past 

 eight or ten years I have been engaged in elaborating Mr. Darwin's 

 theories in the domain of psychology, and I can not allude to my own 

 work in this connection without expressing the deep obligations under 

 which I lie to his ever-ready and ever-generous assistance — assistance 

 rendered not only in the way of conversation and correspondence, but 

 also by his kindness in making over to me all his unpublished manu- 

 scripts, together with the notes and clippings which he had been mak- 

 ing for the past forty years in psychological matters. I have now 

 gone carefully through all this material, and have published most of 

 it in my work on " Mental Evolution in Animals." I allude to this 

 work on the present occasion in order to observe that, as it has so 

 recently come out, I shall feel myself entitled to assume that few have 

 read it ; and therefore I shall not cramp my remarks by seeking to 

 avoid any of the facts or arguments therein contained. 



As there are not many words within the compass of our language 

 which have had their meanings less definitely fixed than the word 

 " instinct," it is necessary that I should begin by clearly defining the 

 sense in which I shall use it. 



In general literature and conversation we usually find that instinct 

 is antithetically opposed to reason, and this in such wise that, while 

 the mental operations of the lower animals are termed instinctive, 

 those of man are termed rational. This rough-and-ready attempt at 

 psychological classification has descended to us from remote antiquity, 

 and, like kindred attempts at zoological classification, is not a bad one 

 so far as it goes. To divide the animal kingdom into beasts, fowls, 

 fish, and creeping things, is a truly scientific classification as far as it 

 goes, only it does not go far enough for the requirements of more care- 

 ful observation ; that is to say, it only recognizes the more obvious 

 and sometimes only superficial differences, while it neglects the more 

 hidden and usually more important resemblances. And to classify all 

 the mental phenomena of animal life under the term "instinct," while 

 reserving the term " reason " to designate a mental peculiarity dis- 

 tinctive of man, is to follow a similarly archaic method. It is quite 

 true that instinct preponderates in animals, while reason preponderates 

 in man. This obvious fact is what the world has always seen, just as 

 it saw that flying appeared to be distinctive of birds, and creeping of 



