I now go into the theoretical ideas which alone have shown themselves useful in making the conception of repression more definite. It is above all necessary that we progress from a purely descriptive meaning of the word "unconscious" to its more systematic meaning; that is, we come to a point where we must call the consciousness or unconsciousness of a psychic process only one of its attributes, an attribute which is, moreover, not necessarily unequivocal. If such a process remained unconscious, then this separation from consciousness is perhaps only an indication of the fate to which it has submitted and not this fate itself. To bring this home to us more vividly, let us assume that every psychological process--with one exception, which I will go into later--first exists in an unconscious state or phase and only goes over from this into a conscious phase, much as a photographic picture is first a negative and then becomes a picture by being printed. But not every negative need become a positive, and just as little is it necessary that every unconscious psychological process should be changed into a conscious one. We find it advantageous to express ourselves as follows: Any particular process belongs in the first place to the psychological system of the unconscious; from this system it can under certain conditions go over into the system of the conscious. The crudest conception of these systems is the one which is most convenient for us, namely, a representation in space. We will compare the system of the unconscious to a large ante-chamber, in which the psychic impulses rub elbows with one another, as separate beings. There opens out of this ante-chamber another, a smaller room, a sort of parlor, which consciousness occupies. But on the threshold between the two rooms there stands a watchman; he passes on the individual psychic impulses, censors them, and will not let them into the parlor if they do not meet with his approval. You see at once that it makes little difference whether the watchman brushes a single impulse away from the threshold, or whether he drives it out again after it has already entered the parlor. It is a question here only of the extent of his watchfulness, and the timeliness of his judgment. Still working with this simile, we proceed to a further elaboration of our nomenclature. The impulses in the ante-chamber of the unconscious cannot be seen by the conscious, which is in the other room; therefore for the time being they must remain unconscious. When they have succeeded in pressing forward to the threshold, and have been sent back by the watchman, then they are unsuitable for consciousness and we call them _suppressed_. Those impulses, however, which the watchman has permitted to cross the threshold have not necessarily become conscious; for this can happen only if they have been successful in attracting to themselves the glance of the conscious. We therefore justifiably call