*Prematurity.*--Such a factor is the spontaneous sexual _prematurity_ which can be definitely demonstrated at least in the etiology of the neuroses, though in itself it is as little adequate for causation as the other factors. It manifests itself in a breaking through, shortening, or suspending of the infantile latency period and becomes a cause of disturbances inasmuch as it provokes sexual manifestations which, either on account of the unready state of the sexual inhibitions or because of the undeveloped state of the genital system, can only carry along the character of perversions. These tendencies to perversion may either remain as such, or after the repression sets in they may become motive powers for neurotic symptoms; at all events, the sexual prematurity renders difficult the desirable later control of the sexual impulse by the higher psychic influences, and enhances the compulsive-like character which even without this prematurity would be claimed by the psychic representatives of the impulse. Sexual prematurity often runs parallel with premature intellectual development; it is found as such in the infantile history of the most distinguished and most productive individuals, and in such connection it does not seem to act as pathogenically as when appearing isolated. *Temporal Factors.*--Just like prematurity, other factors, which under the designation of _temporal_ can be added to prematurity, also demand consideration. It seems to be phylogenetically established in what sequence the individual impulsive feelings become active, and how long they can manifest themselves before they succumb to the influence of a newly appearing active impulse or to a typical repression. But both in this temporal succession as well as in the duration of the same, variations seem to occur, which must exercise a definite influence on the experience. It cannot be a matter of indifference whether a certain stream appears earlier or later than its counterstream, for the effect of a repression cannot be made retrogressive; a temporal deviation in the composition of the components regularly produces a change in the result. On the other hand impulsive feelings which appear with special intensity often come to a surprisingly rapid end, as in the case of the heterosexual attachment of the later manifest homosexuals. The strivings of childhood which manifest themselves most impetuously do not justify the fear that they will lastingly dominate the character of the grown-up; one has as much right to expect that they will disappear in order to make room for their counterparts. (Harsh masters do not rule long.) To what one may attribute such temporal confusions of the processes of development we are hardly able to suggest. A view is opened here to a deeper phalanx of biological, and perhaps also historical problems, which we have not yet approached within fighting distance.