FREUD'S THEORIES OF THE UNCONSCIOUS 357 



complex, they say, that if they occurred in an animal, for example, we 

 would unhesitatingly call them mental. They are of course physiolog- 

 ical, hut it is hard to explain their apparent intelligence without sup- 

 posing that they are mental as well. The conflict is very like that now 

 waging between the two schools of animal psychologists, those who 

 would reduce everything in the life of the animal to a series of mechan- 

 ical reflexes, and those who look for signs of conscious intelligence. 

 Like this conflict, too, it is one which can never be decided by intro- 

 spection, it is only as results accumulate that the balance will swing to 

 one side or the other. In accordance with the law of economy that 

 regulates scientific thinking, it would seem that such activities ought 

 to be explained in physiological terms if it is possible to do so ; in this 

 ease the question becomes: are they too complex to be so explained? 



The thing of all others most needful here, then, would seem to be 

 more evidence as to the nature of such unconscious activities. Such a 

 body of evidence has been brought forward by Professor Freud, of 

 Vienna, whose work is just beginning to be known in this country. 

 Professor Freud is primarily an alienist, a former student of Charcot 

 at the Salpetriere. In the course of a long practise with neurotic 

 patients, he has arrived gradually at theories of the mechanism of the 

 unconscious, which, if they are substantiated, will go far to revolu- 

 tionize present psychological conceptions. 



Freud's theory is unique in that he supposes the region of the 

 unconscious to be built up of two distinct layers, and that he would 

 explain all the facts of unconscious action as due to the interaction of 

 these two layers. 



The upper layer is a sort of vestibule to consciousness. When, for 

 example, as in the case cited above, we try in vain to recall a name, and 

 later find it coming of itself into consciousness, Freud would explain 

 the case as follows : The train of conscious activity set up by the effort 

 has, as soon as attention was turned away from it, sunk below the 

 threshold of consciousness. But it does not at once die away. The 

 activity rather goes on exactly as though it were in consciousness, new 

 associative connections are made, and by and by the associative train 

 succeeds in reaching the name of which we were in search. This now 

 appears in consciousness, seemingly out of all associative connection, 

 and yet a train of association has led to its discovery, only it was a train 

 of unconscious association. So during the day we break off scores of 

 trains of thought without carrying them to a conclusion, because they 

 are too trivial, too complex, too unwelcome, to occupy the mind further. 

 Such trains of thought drop below the threshold, and there may form 

 new associative connections. If these are strong enough, they may 

 again appear above the threshold, apparently without cause. If such 

 connections are not formed readily, the activity may die out without 



