That repressed sexuality plays an important part in the conflicts of the ego is well known to all who are acquainted with analytical psychology. According to Freud, the sexual impulse dates from earliest childhood and is an essential element in every stage of self-appreciation. A summary of the process by which the infantile ego develops to maturity is as follows: The child is by nature "polymorphous perverse"--that is, both physically and psychically he possesses elements which in the mature individual would be considered perversions. Physiologically, what are known as "erogenous zones"--tissue which is capable of what in mature life is sexual excitation--are diffused through the organism. As the child passes through the "latent period" of later childhood and adolescence, these "erogenous zones" are concentrated as it were in the organs which are to serve the purpose of reproduction. If for any reason this process of concentration is checked, and remains in later life incomplete, the mature individual will be afflicted with certain tendencies to sex perversion. Similarly the psychosexual passes through a metamorphosis in normal development. The erotic interest of the child, at first quite without any object at all, is soon attached to one or the other of the parents, then, in the "narcissus period" is centered upon the individual himself, after which, normally, but not without some storm and stress, it becomes detached and capable of "object love"--that is, love of a person of the opposite sex. This psychic process is by no means a smooth and easy matter. It is attended at every stage with such dangers that a very large number of people never achieve it entire. Various kinds of "shock" and wrong educational influence, or overindulgence on the part of the parents, may cause the psychosexual interest of the ego--or "libido"--to remain "fixed" at some point in its course. It may retain vestiges of its early undifferentiated stage, appearing then in the perverted forms of "masochism"--sexual enjoyment of self-torture--or "sadism"--sexual pleasure in torturing others. Or the libido may remain fixed upon the parent, rendering the individual in some degree incapable of a normal mature love life. He has never quite succeeded in severing his infantile attachment to his mother and transferring his interest to the world of social relations and mature experiences. If he meets with a piece of misfortune, he is likely to seek imaginary security and compensation by a "regression" of the libido and a revival of childlike affection for the mother image. As this return is, in maturity, unconsciously resisted by the horror of incest, a conflict results. The individual then develops certain mechanisms or "complex formations" in defense of his ego against this painful situation. The withdrawal of the libido from the ordinary affairs of life renders the latter valueless. Thoughts of death and like compulsory mechanisms ensue. The patient has become a neurotic.