iv MENTAL DEVELOPMENT 57 



may serve the future, however, and that for one of two 

 reasons. First, the mind may be dominated by a purpose. 

 In that case, while the purpose lasts .there will be satisfac- 

 tion only in that which tends to forward it, and dissatis- 

 faction with everything else. It fixes the feeling tone 1 

 which constitutes the co-present organic condition domina- 

 ting each adjustment from moment to moment. Thus, 

 in the game the desire to win is present in the form of 

 a tension, stimulating and directing each sensori-motor 

 response. The response is guided and adjusted to the act 

 which at any given moment relieves the tension, and as 

 under the influence of intelligent purpose the act which 

 relieves the tension, which satisfies, or establishes momen- 

 tary equilibrium, is normally one which brings us nearer 

 to the end, the result is that the purpose gets itself 

 accomplished. 



But without the formation of purpose it is possible that 

 actions should be co-ordinated in series, so as to produce 

 results of importance to the organism. This brings us 

 to the second method in which sensori-motor response 

 may serve the future. Just as the hereditary structure 

 may determine a reflex response, which performs a function 

 without intelligence or purpose, so it may determine a 

 tension of feeling guiding a train of sensori-motor acts 

 and indeed of structural and reflex acts along with them 

 and persisting till a result of importance to the organism 

 is attained. Trains of action so determined are generically 

 instincts. We may conceive that where there is a well- 

 developed instinct, but little or no intelligence, the train 

 of action is determined by a tension, which at any given 

 point is satisfied only by a performance which falls in with 

 the course leading up to the final accomplishment of the 

 result, and by no other. The solitary wasp dragging a 

 spider to its hole does not act altogether mechanically, nor 

 altogether intelligently. But it is not satisfied till it gets 

 the spider into the hole. That result, and no other, relieves 

 the tension. Where intelligence arises within the sphere 

 of instinct, it probably takes short views at the outset, and 



1 On the assumptions involved in postulating feeling a few words are 

 said in another connection. See below, Ch. V. 3, p. 64. 



