The hereditary sexual constitution provides us with manifold tendencies, varying with the special emphasis given one or the other component of the instinct, either individually or in combination. With the factor of infantile experience, there is again built up a complementary series within the sexual constitution which is perfectly comparable with our first series, namely, the gradations between disposition and the chance experiences of the adult. Here again we find the same extreme cases and similar relations in the matter of substitution. At this point the question becomes pertinent as to whether the most striking regressions of the libido, those which hark back to very early stages in sexual organization, are not essentially conditioned by the hereditary constitutional factor. The answer to this question, however, may best be put off until we are in a position to consider a wider range in the forms of neurotic disease. Let us devote a little time to the consideration of the fact that analytic investigation of neurotics shows the libido to be bound up with the infantile sexual experiences of these persons. In this light they seem of enormous importance for both the life and health of mankind. With respect to therapeutic work their importance remains undiminished. But when we do not take this into account we can herein readily recognize the danger of being misled by the situation as it exists in neurotics into adopting a mistaken and one-sided orientation toward life. In figuring the importance of the infantile experiences we must also subtract the influences arising from the fact that the libido has returned to them by regression, after having been forced out of its later positions. Thus we approach the opposite conclusion, that experiences of the libido had no importance whatever in their own time, but rather acquired it at the time of regression. You will remember that we were led to a similar alternative in the discussion of the Oedipus-complex.