378 REFLEX ACTION, INSTINCT, AND REASON 



learned nothing, would still be as blank as that of a newly born 

 infant. 



626. We always measure the intelligence of an animal by its 

 power of profiting by experience. Thus, a cat is more intelligent 

 than a rabbit, because it can learn more ; a dog, for the same 

 reason, is still more intelligent. An animal with a purely instinc- 

 tive mind, with ' innate and inherited ' impulses to act in this or 

 that way but no memory, can have no conception of its past, and 

 therefore no idea of its future. It lives wholly in the immediate 

 present, feeling but not thinking. It acts entirely on simple 

 inclination, not on reflection. Like the caterpillar building his 

 cocoon, it makes provision for the future, not with any idea of 

 providing, but simply because stimulus from the environment 

 causes it to react in a certain way, gives it an impulse to a certain 

 course of action the performance of which bestows pleasure of the 

 kind that a child derives from playing or eating, and with the 

 ultimate result of which it is no more consciously concerned than 

 a playing child. If a caterpillar sheltered in a hole with the idea, 

 founded on experience, of avoiding danger, his action would be 

 intelligent. If, appealing to a memory, in which a great number 

 of complex experiences were stored, he took thought and designed 

 himself a shelter in which provision was made for all sorts of re- 

 membered or imagined dangers, his action would be rational. But 

 if, making no appeal to the past nor taking any thought for the future, 

 he builds only because impelled by an ' innate ' inclination, then, no 

 matter how elaborate the edifice he rears, his action is instinctive. 



627. In proportion as animals are low in the scale of life, they 

 appear incapable of learning. Thus, memory seems rudimentary 

 or absent in most insects. But often they are wonderfully equipped 

 by instinct. To take, again, the example of the caterpillar: on 

 emerging from the egg, driven by an innate inclination which is 

 the instinct, the animal moves from place to place. It co-ordinates 

 its muscles without practice perfectly at the first attempt. In 

 other words, its movements are instinctive in a double sense ; they 

 are prompted by instinct and they are co-ordinated instinctively. 

 The animal does not learn to do them. In the human being, on 

 the other hand, even when the prompting is instinctive, the power 

 of co-ordinating the movements for the performance of the 

 instinctive act is for the most part slowly and laboriously acquired 

 through experience. For example, maternal love is an instinct ; 

 but facility in all the movements to which the instinct prompts the 

 mother is ' acquired.' 



