Literature records many fully developed cases of neuroses. A story like the _Fall of the House of Usher_ presents a complete case of a neurosis. Characters in literature who commit suicide, like Werther and Hedda Gabler, are victims of neurosis; sex is usually at the bottom of their difficulties. Every sufferer then in literature is a partly or fully developed case of neurosis; at least an emotional disturbance due to sex causes, akin to the neurosis, is always present. This fact is sufficient for the laymen to know without their making a deep inquiry into the nature of these neuroses and attempting to classify them. Here the work of the physician begins and a penetrating insight into the species of neuroses described in literature can be made only by the psychoanalyst. Nevertheless, there are some cases that even the layman may recognise as soon as he has familiarised himself with the Freudian views of the neuroses. In English the best technical books on the subject are the translation of Hitschman's _Freud's Theories of Neuroses_, Brill's _Psychoanalysis_ and Brink's _Morbid Fears and Compulsions_. Some of Freud's own essays have been translated by Dr. Brill in _Selected Papers on Hysteria_. Freud divides the neuroses into two classes, the true or actual neuroses, and the psychoneuroses. The true neuroses are neurasthenia and anxiety neurosis, which formerly was included under neurasthenia, but which Freud set off as a separate class. He calls these true neuroses because there are present abnormal disturbances of the sexual function, not necessarily due to heredity. Neurasthenia is due to excessive physical abuse, and the anxiety neurosis results from abstinence or unsatisfactory gratification. All agencies which prevent the psychic utilisation of the physical excitement lead to anxiety neurosis. Literature gives us cases of true neuroses, but they are not as frequent as the other class, the psychoneuroses. The psychoneuroses are due to repressions but date back to infancy; the influence of heredity is important; unconscious factors are at work. The child's relation to his parents and his infantile sex life have great influence on his future. The crisis comes when a love repression in later life breaks out. The psychoneuroses are hysteria, compulsion neurosis, and mixed cases, especially anxiety hysteria. In hysteria the patient suffers from reminiscences, and his recent experiences are unconsciously attached to infantile sexual impressions. Instead of solving his love difficulties he builds fantasies. Certain mental impressions remain fixed. The early painful effects struggle to consciousness, but instead are transformed into uncommon inhibitions, by a process known as conversion.