conversion" for the latter process. Part of our mental energy is, under normal conditions, conducted off by way of physical innervation and gives what we call "the expression of emotions." Hysterical conversion exaggerates this part of the course of a mental process which is emotionally colored; it corresponds to a far more intense emotional expression, which finds outlet by new paths. If a stream flows in two channels, an overflow of one will take place as soon as the current in the other meets with an obstacle.
You see that we are in a fair way to arrive at a purely psychological theory of hysteria, in which we assign the first rank to the affective processes. A second observation of Breuer compels us to ascribe to the altered condition of consciousness a great part in determining the characteristics of the disease. His patient showed many sorts of mental states, conditions of "absence," confusion and alteration of character, besides her normal state. In her normal state she was entirely ignorant of the pathogenic scenes and of their connection with her symptoms. She had forgotten those scenes, or at any rate had dissociated them from their pathogenic connection. When the patient was hypnotized, it was possible, after considerable difficulty, to recall those scenes to her memory, and by this means of recall the symptoms were removed. It would have been extremely perplexing to know how to interpret this fact, if hypnotic practice and experiments had not pointed out the way. Through the study of hypnotic phenomena, the conception, strange though it was at first, has become familiar, that in one and the same individual several mental groupings are possible, which may remain relatively independent of each other, "know nothing" of each other, and which may cause a splitting of consciousness along lines which they lay down. Cases of such a sort, known as "double personality" ("double conscience"), occasionally appear spontaneously. If in such a division of personality consciousness remains constantly bound up with one of the two states, this is called the conscious mental state, and the other the unconscious. In the well-known phenomena of so-called post hypnotic suggestion, in which a command given in hypnosis is later executed in the normal state as though by an imperative suggestion, we have an excellent basis for understanding how the unconscious state can influence the conscious, although the latter is ignorant of the existence of the former. In the same way it is quite possible to explain the facts in hysterical cases. Breuer came to the conclusion that the hysterical symptoms originated in such peculiar mental states, which he called "hypnoidal states." (hypnoide Zustände.) Experiences of an emotional nature, which occur dur-
