THE FIELD OF LOGIC 317 



tion in still another form, as a psychological process simply, does 

 it also serve as a logical one? The answers to these questions can be 

 determined only by first noting what psychology can say about it 

 as a mental process. 



In the first place, psychology can analyze it, and so determine 

 its elements and their connections. It can thus distinguish it from all 

 other mental processes by pointing out its unique elements or their 

 unique and characteristic connection. No one will deny that a 

 judgment is different from an emotion, or that an act of reasoning is 

 different from a volition; and no one will claim that these differences 

 are entirely beyond the psychologist's power to ascertain accurately 

 and precisely. Still further, it appears possible for him to determine 

 with the same accuracy and precision the distinction in content and 

 connection between processes which are true and those which are 

 false. For, as mental processes, it is natural to suppose that they 

 contain distinct differences of character w r hich are ascertainable. 

 The states of mind called belief, certainty, conviction, correctness, 

 truth, are thus, doubtless, all distinguishable as mental states. It 

 may be admitted, therefore, that there can be a thoroughgoing 

 psychology of logical processes. 



Yet it is quite evident to me that the characterization of a mental 

 process as logical is not a psychological characterization. In fact, 

 I think it may be claimed that the characterization of any mental 

 process in a specific way, say as an emotion, is extra-psychological. 

 Judgments and inferences are, in short, not judgments and inferences 

 because they admit of psychological analysis and explanation, any 

 more than space is space because the perception of it can be worked 

 out by genetic psychology. In other words, knowledge is first know- 

 ledge, and only later a set of processes for psychological analysis. 

 That is why, as it seems to me, all psychological logicians, from Locke 

 to our own day, have signally failed in dealing with the problem of 

 knowledge. The attempt to construct knowledge out of mental 

 states, the relations between ideas, and the relation of ideas to 

 things, has been, as I read the history, decidedly without profit. 

 Confusion and divergent opinion have resulted instead of agreement 

 and confidence. On precisely the same psychological foundation, 

 we have such divergent views of knowledge as idealism, phenomenal- 

 ism, and agnosticism, with many other strange mixtures of logic, 

 psychology, and metaphysics. The lesson of these perplexing theories 

 seems to be that logic, as logic, must be divorced from psychology. 



It is also of importance to note, in this connection, that the deter- 

 mination of a process as mental and as thus falling within the domain 

 of psychology strictly, has by no means been worked out to the 

 general satisfaction of psychologists themselves. Recent literature 

 abounds in elaborate discussion of the distinction between what is 



