According to Demoor, “Atrophy begins with function when an organ has become useless. This uselessness may arise from two causes: the function may be no longer useful to the individual or to the species, or it may be assumed by another organ.” When an organism turns parasite it is an economy of nutrition and energy to save as much as possible. The tendency of parasitism is to dispense with unnecessary functions in the struggle for existence. The loss of function is from the less useful, to the more useful, to the functions absolutely indispensable to survival; from the less essential, to the more essential, to functions absolutely essential to the life existence of the individual. The life activity of the parasite becomes more and more narrowed, circumscribed, and dwindles down to a few functions requisite to its life existence, namely self-preservation, nutrition, and reproduction. With the further increase of parasitism even the digestive and reproductive functions become simplified, the parasitic individual becomes reduced to the most fundamental of all impulses, the impulse of self-preservation and reproduction. The penalty of parasitic life is the _simplification_ of organic activities, the atrophy of all higher and complex life processes. This is what takes place in the case of the psychopathic individual. All higher activities, all higher interests cease. In many neurotic cases of the severe type even _the sexual instinct becomes gradually atrophied. The patient’s life is narrowed down to the impulse which is absolutely requisite for individual life existence, namely the impulse of self-preservation with its concomitant fear instinct._ The growth of the impulse of self-preservation with its fear instinct brings about their hypertrophy which in turn hastens the degenerative processes or atrophy of all higher and more complex activities. The psychopathic patient in the process of degeneration and atrophy falls so low that not only moral, social, intellectual, but simpler psychomotor reactions become gradually diminished and atrophied. _In severe cases even the instinct of sex, requisite for the preservation of the species, is made subservient to the impulse of self-preservation and the fear instinct._ In psychopathic life all activities are narrowed down to the pettiness of individual existence. It is not sex, it is not species-interests, nor conflicts, nor self-repressions that trouble the neurotic patient. An abnormal impulse of self-preservation and fear instinct are at the bottom of all psychopathic miseries. _All psychopathic, neurotic interests are reduced to the sorry life of self and fear._