PROBLEMS EMPHASIZED BY PRAGMATISM 399 



complexity. On the other hand, if I can do anything to awaken your 

 interest in the psychological character of these problems, perhaps I 

 may indirectly help to awaken interest in their logical aspect. 



Let me repeat the list of the problems to which I have called atten- 

 tion, emphasizing the sense in which each one of them is a psycho- 

 logical problem. I mention the fact that a science which is testing 

 hypotheses deduces the logical consequences of these hypotheses. The 

 process may be an extended one. ^Vhat is the psychology of deduction? 

 What happens when a process of deduction takes place? In some 

 respects this problem has indeed been repeatedly dealt with from the 

 psychological point of view. I do not wish in the least to deny that the 

 analyses of Professor Pillsbury and others have contributed to this 

 problem, but just because these psychologists have been so little inter- 

 ested in the logic of tlie deductive process they have failed, in my opin- 

 ion, to emphasize some of its most important psychological aspects. 

 Yet their own discussions emphasize the need of such a psychology. 

 Here lies the first of the problems to which I now call attention. 



Secondly, the pragmatists in speaking of the working hypothesis 

 have emphasized, as Professor Moore has recently done, the fact that 

 the agreement of an assertion or idea with its expected workings con- 

 stitutes the test of its truth so far as up to a certain point in our 

 investigations we may happen to have gone. I have called attention to 

 the difference between an expectation and an assertion or a denial. 

 One goes to the play expecting amusement. At the end of the play, have 

 his expectations been met or not? The question may be unanswerable in 

 any definite way. The play was amusing, and yet perhaps not so very 

 amusing, or not so amusing as one could have wished it to be. One goes 

 away partially disappointed, partially pleased. One is not so disap- 

 pointed but that one continues to go to plays over and over again. 

 One is not so pleased that he expresses himself very enthusiastically. 

 What ideas with regard to the amusing character of plays have been 

 precisely tested, so long as one remains in this state of mind ? On the 

 other hand, through a deductive process the occurrence of an eclipse 

 is precisely predicted. The eclipse is observed, its beginning is noted 

 ■with an accuracy as great as the errors of observation permit. A pre- 

 cise assertion is made as to the agreement between the prediction and 

 the observation. When the assertion has received its proper qualifica- 

 tions with regard to probable error and the rest, the assertion appears 

 in the records as true or false. In this case an issue is met and some- 

 thing is tested, yes or no. I now ask, what is the psychology' of asser- 

 tion and denial, of the difference between yes and no ? In what way does 

 this difference, namely that between yes and no, differ from any other 

 kind of difference? This problem I mention, without hoping in this 

 paper to do more than mention it. I called attention to this psycho- 



