It is perhaps necessary here briefly to refer to the teaching of Sigmund Freud of Vienna, because his views have attracted a great deal of attention in this country and have become familiar to a great part of the reading public. Freud believes that the origin of many abnormal mental states and of the disturbances of conduct which are dependent upon them is to be traced back to forgotten experiences, the recollection of which has faded from the conscious mind, but which are still capable of exerting an indirect influence. He regards the process of forgetting, not as merely a passive fading of mental impressions, but as an active process of repression, by which the experience, and especially the unpleasant experience, is thrust and kept out of consciousness. There thus arises a mental conflict between the forces of repression and the forces which tend to obtrude the recollection into consciousness, and at times the energy engendered in this conflict escapes from the censorship of the repressing forces and finds vent in the production of abnormal mental states or disorders of conduct. Thus to take a simple example, a business man who has had a trying day at the office, on returning home in the evening may succeed in thrusting out of his consciousness the thought of his disappointments and worries, yet the disturbance in his mind may show itself in quarrels with his wife or complaints of the quality of the cooking at dinner. Freud has called attention to the part which the suppressed and long-forgotten experiences of early childhood play in the production of neuroses of all sorts at a later date, and he has laid especial emphasis on sexual experiences as peculiarly fruitful causes of such disturbances. Those who have embraced Freud's teaching have gone even farther than he in this direction, and by psycho-analysis--that is to say, by attempting in intimate conversation to arouse the dormant memory and lay bare the buried complex, the suppression of which has produced the conflict in the mind of the sufferer--will seldom fail to discover the influence of sexual forces and sexual attractions which, while capable of causing disorders of mind and of conduct, show themselves only obscurely and indirectly, as, for example, in dreams or in symbolic form.