376 JOHN LINCK ULRICH 



cessful. Not until the successful or unsuccessful movements 

 have been performed, can it be judged which movements of the 

 number made are the most important. The unsuccessful kind 

 are regarded as of little importance and of little consequence in 

 learning, as compared with the successful. The latter alone are 

 supposed to have an enduring effect. Since the unsuccessful 

 movements do not disappear immediately, this division of all 

 movements may be said to exist till the successful alone remain. 

 Such an antithetical division of all movements based upon the 

 working concept of " trial and error" must in no wise be consid- 

 ered a physiological classification of integrated movements; nor 

 can it approach such a classification, for it is rather a personal 

 estimate of movements. 



Though in this twofold division of movements, the unsuccess- 

 ful are regarded of less importance in learning, the fact remains 

 that the relation of these to the successful must be shown. Sup- 

 porters of intelligent effort of animals have usually combined 

 with the antithetical concept another concept, pleasure-pain. 

 In antithesis to pain, a pleasure-giving quality produces retention 

 or fixation of successful movements, and in antithesis to pleasure, 

 pain eliminates the unsuccessful kind. The successful movements 

 are fixated, or stamped in, supposedly, because either pleasure 

 is derived at the time of the performance of them, or arises soon 

 after when reward is obtained. In any case it must be present 

 in its most positive form at the time when it is in contrast to pre- 

 viously unpleasant or painful "sensations." When pleasure arises 

 at the time of success, the contrast is supposed to be immediate, 

 and an associated physiological process, such as an increase in 

 bodily tone, a higher metabolic rate, occurs at the time of stamp- 

 ing in the successful movements. When pleasure is supposed 

 to come after the act, that is at the time of reward, the contrast 

 to pain evidently is not immediate with the performance of the 

 successful movement, but is established later. If this is true, 

 then what is painful must include everything before reward, in- 

 clusive of the final act itself, which can scarcely be painful unless 

 pleasure is an anthropomorphic agent, capable of selecting the 

 pleasurable-successful from the painful-unsuccessful movements. 



