384 JOHN LINCK ULRICH 



of "sensory association/' so that the mechanism for " associative 

 memory" is in reality the establishment of " sensory association." 

 There remains practically no difference in the two forms. One 

 redeeming feature in this theory of learning is, that movements 

 are dependent upon the existing organization of an animal, not 

 upon modifications of structure in the nervous system. 



With the persistence of the idea of " sensory association" in 

 learning and with the acceptance of the doctrine of forced move- 

 ments or of a twofold division of movement into the " successful" 

 and the " unsuccessful," or the "congruous" and the "incongru- 

 ous," there remains as a result little that is strikingly new or 

 radically different, in all these theories of learning in animals. 

 Some of them are formulated with the view of removing one 

 objection, or all objections, to the existence of the "psychic," 

 or "pleasure-pain." Into these different theories, when sup- 

 porting or discrediting one view or another, supposed physiologi- 

 cal explanations of a certain kind have been freely introduced. 

 All of them cling to the basic supposition that a "sensory asso- 

 cation" is brought about. In one theory it is conditioned by the 

 performance of forced movements; in the other by the existence 

 of antithetical movements, either with or without the influence 

 of "pleasure-pain." All these theories are based upon sensory 

 analysis and show the influence of analytical psychology. 



As with all theories developed by analytical methods, these 

 fail to consider matter that may interfere with the main body 

 of their thesis. Mainly the "successful" attainment of a feat, 

 the appearance of the "congruous" movement in learning is 

 considered and little attention is paid to failure. Upon the oc- 

 currence of the "successful," or the "congruous," and the per- 

 sistence of either, or upon the production of a directive type of 

 movement, all these theories are dependent. Scarcely anything 

 is said of the positive influence that other movements may have 

 or of the significance of a failure to solve a problem or to learn 

 it. Is it supposed that when the "successful" or the "congru- 

 ous" movement is not performed, that the mechanism for the 

 production of these movements is wanting? Is it assumed that 

 certain neural arcs are absent or undeveloped, that sensory exci- 



