An ordinary clock can be handled roughly without disturbance of its internal workings, but the delicate and complicated mechanism of a chronometer requires careful handling and special, favorable conditions for its normal functioning. Unfavorable conditions are more apt to affect a highly complex mechanism than a roughly made instrument. It is quite probable that it is the superior minds and more highly complex mental and nervous organizations that are subject to psychopathic states or states of dissociation. Of course, unstable minds are also subject to dissociative states, but we must never forget the fact that highly organized brains, on account of their very complexity, are apt to become unstable under unfavorable conditions. A predisposition to dissociation may occur either in degenerative minds or in minds superior to the average. _Functional psychosis requires a long history of dissociated, subconscious shocks, suffered by a highly or lowly organized nervous system, a long history dating back to early childhood._ As Mosso puts it: “The vivid impression of a strong emotion may produce the same effect as a blow on the head or some physical shock.” We may, however, say that no functional psychosis, whether somatopsychosis or psychoneurosis, can ever be produced simply by physical shocks. _In all functional psychoses there must be a mental background, and it is the mental background alone that produces the psychosis and determines the character of the psychopathic state._ _Fear is an important factor in the etiology of psychopathic affections which include somatopsychoses and psychoneuroses._ To regard fear as “error,” as do some sectarians, is absurd, and is certainly unscientific. Abnormal fear which is the basis of all functional nervous or psychopathic maladies, is essentially a pathological process affecting the organs in general and the nervous system in particular in as definite a way as the invasion and infection of the organism by various species of bacteria, bacilli, and other micro-organisms which attack the individual during his lifetime. Like infectious diseases, the deviations, abnormalities, and excesses of the fear instinct are _acquired_ by the individual in the course of his relations with the external environment, and are as real and substantial as are syphilis, smallpox, diphtheria, cholera, and the bubonic plague. To regard them as imaginary or to relegate them to the action of Providence or to heredity is theoretically a misconception, and practically a great danger to humanity. There is nowadays a veritable craze for heredity and eugenics. Biology is misconceived, misinterpreted, and misapplied to social problems, and to individual needs and ailments. Everything is ascribed to heredity, from folly and crime to scratches and sneezes. The goddess Heredity is invoked at each flea-bite--_in morsu pulicis Deum invocare_.