The mental and the conscious are co-extensive terms. On the other hand, those who have dealt most with the abnormal phenomena, and are less at home in the field of pure psychology, see in such con" Bcious activities something mental as well. The phenomena are so 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 effect. Or such a train of thought may form still other associations, and sink to lower depths of the soul, still to be considered. This upper layer of the unconscious, then, which we find in Freud's theory, is very like the usual sense in which the word " unconscious " is used, especially by those who would see something mental in its activities.
But the unique contribution which Freud has made to the subject is in his theory of the lower layer of the unconscious, which is in many respects totally different in its structure and activities from the upper layer which we have been considering. In order to see his conception more clearly, let us follow for a moment the development of the indi- vidual. We all know that the child exhibits many tendencies which in the adult would be signs of criminality, insanity or abnormality. Our conscious personality as it exists to-day is the result of a long process of growth, each stage built on the ruins of the one beneath. The child is savage, primitive ; it is only by degrees that he becomes adapted to the restraints of our modern civilization, and represses his old activities. But now, says Freud, such repressed activities leave their traces behind. They may not seem to affect us consciously ; we may have even forgotten many of the old ways of thinking and acting, but their traces still exist. What has become of the energy which went to the gratification of our old selfish, individual, feral, modes of thought and action ? With most of us the energy has found for the most part new outlets, it has pro- duced the motive force for new developments. It has been " sub- limated " to higher uses. But the draining off of the energy from the old modes of action has not been complete. The old primitive tenden- cies still persist unconsciously in the best of us, and will crop out in some form or other if the provocation be sufficient. We have repressed our childish desires so long that we may have forgotten that they ever existed, but yet they are not quite dead. Particularly is this true in the realm of sex — for Freud holds that the child has a sex life of his own as truly as the adult. It has, to be sure, not yet come to a head in the sexual organs, but it is none the less existent, and in ways which in the adult would be called perversions; which, indeed, if not repressed, are the origin of perversions in later life. Now these old ways of sexual satisfaction are usually repressed under the influence of the environment, yet the tendency to their gratification still exists; we may see it cropping out in the most normal of us in dreams, for ex- ample. The energy that went to the satisfaction of such impulses has for the most part been drained off into new channels, but a little of it still remains locked up with the old complexes. Perhaps none of us have as much energy at our disposal for mental work as we ought to have, for some of it still is attached to old and outworn tendencies, making it a little easier and a little more possible for them to come into operation under favoring circumstances than for new tendencies so to do.
Now, for Freud, it is of just such cast off complexes, each with its own complement of energy, that the lowest level of the unconscious is made up. All the unethical acts and unsocial ways of thought of the child, repugnant to us to-day, still exist in the lowest dark chamber of the soul, not strong enough to break out into action, but alive. It is the penalty which we pay for our civilization, that it imposes standards of thought and action which are foreign to the deepest tendencies in us, modes of life of the cave-man and the ages before civilization, which have left their marks on the soul forever. And for all of us there has been some strain in adjusting to its requirements, resulting in the abandonment after a struggle of the old racial ways, and the substitu- tion of newer and more ethical modes of action. But a part of our personality still remains in the troglodytic stage. We may not allow this part expression ; we may not even be conscious that it longer exists, and yet it lives and works below the threshold, just as the remembrance of the death of her mother still affected the girl, though consciously it had lapsed. With the split between childhood and adolescence, the chasm between the old and the new becomes stiU wider; we turn our back more and more on the old ways; they lapse from consciousness more and more completely. Childhood seems a little alien to all of us; there has been a " transvaluation of all values^' so that the remem- brance of how we thought and felt then comes to us with the mark of a little strangeness upon it. It is strange just because we have cast it all out, we have "put away childish things." But in the dark limbo of the unconscious they still live on, unconscious though we may be that such is the case. The lowest level of the unconscious is thus far removed from consciousness in its modes of functioning. The concep- tion that such tendencies still function, still need contiuual, though not conscious repression, is the essential point here.
But now what is the mechanism that prevents us from knowing that these old tendencies are still striving upward toward conscious expres- sion? Consciousness is guarded from a knowledge of their existence and their activities, holds Freud, by the interposition of the upper level of the unconscious. This acts like a censor, a guard at the gate, and will not admit to conscious expression these outworn complexes, because of the pain which they would cause us if we were compelled to take account of them in our thinking. It would require too much energy consciously to keep them down ; so it is the function of the upper level of the unconscious to save consciousness all this trouble, and to leave it free for other things. This it does, in ordinary circumstances, so well that we are not even aware that any repression is going on, or, indeed, that there is anything to repress. We have repressed our old complexes so long and so well that the act of repression has dropped below the conscious level; we are not aware of its existence. But, on the other hand, it is continually going on, for the old complexes are always striving up to expression. And so the system of energy in the unconscious is a two-way system; the upper system keeping down the lower. If this be true, how different is our mind from the report which consciousness