242 THE CASE AGAINST EVOLUTION 



taneous and others merely reflex movements. It paws the 

 ground, prances about, and rubs its nose against the gate. Its 

 futile efforts to pass through the closed gate continue indefi- 

 nitely and aimlessly, until, by some lucky accident, its nose 

 happens to strike against the latch and lift it sufficiently to re- 

 lease the gate. This causes the gate to swing ajar, and the horse 

 rushes out to food and freedom. By the law of contiguity, 

 the vision of free egress through the gate is thereafter firmly 

 associated in the horse's sense-memory with the final sensation 

 experienced in its nose just prior to the advent of the agree- 

 able eventuation of its prolonged efforts. Henceforth the 

 animal will be able to release itself from the enclosure by 

 repeating the concatenated series of acts that memory associ- 

 ates with the pleasurable result. On the second occasion, how- 

 ever, the more remote of its futile acts will have been forgotten, 

 and the process of opening the gate will occupy less time, 

 though probably a certain amount of useless pawing and rub- 

 bing will still persist. Gradually, however, the number of in- 

 efficacious actions will diminish, until, after many repetitions 

 of the experience, only those actions which directly issue in the 

 desirable result will remain in the chain of impressions retained 

 by memory, all others being eliminated. For, by a teleological 

 law, making for economy of effort, all impressions not immedi- 

 ately and constantly connected with the gratification of animal 

 appetites tend to be inhibited. Pawlow's experiments on dogs 

 show that impressions which coincide in time with such gratifi- 

 cation tend to be recalled by a return of the appetitive im- 

 pulse, but are soon disconnected from such association and 

 inhibited, if they recur independently of the recurrence of 

 gratification. For this reason, the horse tends to remember 

 more vividly those actions which are more closely connected 

 with the pleasurable result, and, as its superfluous actions are 

 gradually suppressed by a protective process of inhibition, it 

 gradually comes to run through the series of actions necessary 

 to open the gate with considerable accuracy and dispatch. 

 The point to be noted, however, is that the horse does not 



