=What about Sublimation?= On the other hand, it has been stated in Chapter IV that although this universal urge cannot be repressed, it can be sublimated or diverted to useful ends which bring happiness, not disaster, to the individual. We have a right, then, to ask why this happy issue is not always attained, why sublimation ever fails. If a psycho-neurosis is caused by a failure of an insistent instinct to find adequate expression, by a blocking of the libido or the love-force, what are the conditions which bring about this blocking? The sex-instinct of every respectable person is subject to restraint. Some people are able to adjust themselves; why not all? The question, "What makes people nervous?" then turns out to mean: What keeps people from a satisfactory outlet for their love-instincts? What is it that holds them back from satisfaction in direct expression, and prevents indirect outlet in sublimation? Whatever does this must be the real cause of "nerves." THE CAUSES OF "NERVES" =Plural, not Singular.= The first thing to learn about the cause is that it is not a cause at all, but several causes. We are so well made that it takes a combination of circumstances to upset our equilibrium. In other words, a neurosis must be "over-determined." Heredity, faulty education, emotional shock, physical fatigue, have each at various times been blamed for a breakdown. As a matter of fact, it seems to take a number of ingredients to make a neurosis,--a little unstable inheritance plus a considerable amount of faulty upbringing, plus a later series of emotional experiences bearing just the right relationship to the earlier factors. Heredity, childhood reactions, and later experiences, are the three legs on which a neurosis usually stands. An occasional breakdown seems to stand on the single leg of childhood experiences but in the majority of cases each of the three factors contributes its quota to the final disaster. =Born or Made?= It used to be thought that neurotics, like poets, were born, not made. Heredity was considered wholly responsible, and there seemed very little to do about it. But to-day the emphasis on heredity is steadily giving way to stress on early environment. There are, no doubt, such factors as a certain innate sensitiveness, a natural suggestibility, an intensity of emotion, a little tendency to nervous instability, which predispose a person to nerves, but unless the inborn tendency is reinforced by the reactions and training of early childhood, it is likely to die a natural death. CHILDHOOD EXPERIENCES