102 MIND IN EVOLUTION CHAP. 



ance given to instinct by a nascent intelligence. Where 

 there is no prevision of the end we must suppose the 

 interest to shift as the instinct proceeds through its stages. 

 While the wasp is boring her hole she is wound up to 

 bore. She will get over obstacles in the boring process, 

 but nothing else will interest her. When she has finished, 

 the egg-laying impulse supervenes, and when that has 

 done its work, there follows, we may suppose, the impulse 

 to fly out and explore. Exploring she sees a caterpillar 

 and there follows the interest in stinging, seizing, bearing 

 it back, and finally getting it into the hole. This con- 

 catenation of inward states, not wholly self-determined 

 but related also to the outward and in particular to what 

 has already been done, is a special characteristic of the 

 more elaborate instincts and distinguishes them from the 

 simple sensori-motor act, for in the sensori-motor act 

 there is an adjustment which relieves the tension of the 

 moment, but in the instinct there is this further adjust- 

 ment that the only thing which will relieve the tension at 

 any given moment is the act which, under the circum- 

 stances, is required to serve the ultimate result. The 

 study of instincts reveals that a complex adjustment of 

 this sort is possible without foresight of the ultimate end. 

 Where there is such foresight, the tension involved in 

 purposive effort itself secures the corresponding adjust- 

 ment of interest and conation at every stage. 



1 1 . Human Instinct and the hereditary element. 



Instinct, as involving sensori-motor action as a 

 unit, lies within the limits in which we use the term 

 consciousness. This alone differentiates it fundamentally 

 from the reflex which does not involve consciousness. 

 It is true that reflexes may supply a sensation to con- 

 sciousness, as in the case of coughing, but the sensation 

 is in no way essential to their performance. Of many 

 reflexes or internally determined acts such as breathing 

 we are not normally aware. If consciousness interferes 

 with them at all it is more likely to be for the inhibition 

 of the reflex than for any other purpose. But though 

 reflex behaviour thus stands outside consciousness, there are 

 elements of consciousness which themselves almost appear 



