If the period of infantile sexual investigation comes to an end through an impetus of energetic sexual repression, the early association with sexual interest may result in three different possibilities for the future fate of the investigation impulse. The investigation either shares the fate of the sexuality, the curiosity henceforth remains inhibited and the free activity of intelligence may become narrowed for life; this is especially made possible by the powerful religious inhibition of thought, which is brought about shortly hereafter through education. This is the type of neurotic inhibition. We know well that the so acquired mental weakness furnishes effective support for the outbreak of a neurotic disease. In a second type the intellectual development is sufficiently strong to withstand the sexual repression pulling at it. Sometimes after the disappearance of the infantile sexual investigation, it offers its support to the old association in order to elude the sexual repression, and the suppressed sexual investigation comes back from the unconscious as compulsive reasoning, it is naturally distorted and not free, but forceful enough to sexualize even thought itself and to accentuate the intellectual operations with the pleasure and fear of the actual sexual processes. Here the investigation becomes sexual activity and often exclusively so, the feeling of settling the problem and of explaining things in the mind is put in place of sexual gratification. But the indeterminate character of the infantile investigation repeats itself also in the fact that this reasoning never ends, and that the desired intellectual feeling of the solution constantly recedes into the distance. By virtue of a special disposition the third, which is the most rare and most perfect type, escapes the inhibition of thought and the compulsive reasoning. Also here sexual repression takes place, it is unable, however, to direct a partial impulse of the sexual pleasure into the unconscious, but the libido withdraws from the fate of the repression by being sublimated from the beginning into curiosity, and by reënforcing the powerful investigation impulse. Here, too, the investigation becomes more or less compulsive and a substitute of the sexual activity, but owing to the absolute difference of the psychic process behind it (sublimation in place of the emergence from the unconscious) the character of the neurosis does not manifest itself, the subjection to the original complexes of the infantile sexual investigation disappears, and the impulse can freely put itself in the service of the intellectual interest. It takes account of the sexual repression which made it so strong in contributing to it sublimated libido, by avoiding all occupation with sexual themes.