vi INSTINCT 



circumstances peculiar to the individual. Broadly speak- 

 ing, it is in the last two forms that instinct remains 

 important in the life of man, as laying down a scheme of 

 life to which experience supplies the concrete filling, and 

 as positing ends to which intelligence supplies the series of 

 intermediate steps. 



To sum up. There may be much plasticity of instinct 

 without intelligence, but the fact that instinct is an 

 abiding state of the organism related to an end that may 

 be remote, and that the behaviour which it dictates is 

 from the first determined by complex conditions, and not 

 by a single stimulus, makes possible those more individual 

 and original adjustments of means to ends which we call 

 Intelligent. Intelligence, if this view is correct, arises 

 within the sphere of instinct ; indeed, we can draw no 

 sharp and certain line between them in nature. Yet in 

 idea they are quite distinct. In so far as an act is 

 instinctive, it is not intelligent, and conversely. We will 

 not here try to determine the point at which intelligence 

 first arises in the animal world, but we may say that so far 

 as action is based upon hereditary modes of response, or 

 the composition of such responses, it remains pure instinct. 

 When, on the other hand, means are devised by the 

 individual on the basis of its own experience for com- 

 passing the ultimate or proximate ends to which it is 

 impelled, a new principle appears which we identify pro- 

 visionally with intelligence. At first narrowly limited in 

 scope, intelligence deals with proximate ends. As it 

 expands, it comes to embrace the remoter and at length 

 the ultimate end to which action is directed. Along with 

 this advance the power of choosing the means best suited 

 to the purpose expands, and the determination of successive 

 stages of action by hereditary structure simultaneously 

 disappears. Thus, whether involving intelligence or not, 

 instinct is the abiding state directing action to the attain- 

 ment of certain results, but if it is pure instinct the 

 actions are all reflex or sensori-motor. They are modified 

 and directed without prevision of results by the interest 

 which forms the abiding state. Modification of hereditary 

 action not thus explicable must be referred to the assist- 



