Of course, I do not mean to suggest that, when any woman becomes a prostitute, it is because of an irresistible, inborn craving. Probably most women have both possibilities in them, the mother and the prostitute. What is to happen in cases of doubt depends on the man who is able to make the woman a mother, not merely by the physical act but by a single look at her. Schopenhauer said that a man’s existence dates from the moment when his father and mother fell in love. That is not true. The birth of a human being, ideally considered, dates from the moment when the mother first saw or heard the voice of the father of her child. Biological and medical science, under the influence of Johannes Müller, Th. Bischoff, and Darwin have been completely opposed, for the last sixty years, to the theory of “impression.” I may later attempt to develop such a theory. For the present I shall remark only that it is not fatal to the theory of impression that it does not agree with the view which regards the union of an ovum and spermatazoon as the only beginning of a new individual; and science will have to deal with it instead of regarding it as being opposed to all experience and so rejecting it. In an _a priori_ science such as mathematics, I may take it for granted that even on the planet Jupiter 2 and 2 could not make 5, but biology deals only with propositions of relative universality. Although I support the theory of the existence of such a power of impression, it must not be supposed that I think that all malformations and abnormalities, or even any large number of them, are due to it. I go no further than to say that it is possible for the progeny to be influenced by a man, although physical relations between him and the mother have not taken place. And just as Schopenhauer and Goethe were correct in their theory of colour, although they were in opposition to all the physicists of the past, present, and future, so Ibsen (in “The Lady from the Sea”) and Goethe (in “Elective Affinities”) may be right against all the scientific men who deal with the problems of inheritance on a purely physical basis. If a man has an influence on a woman so great that her children of whom he is not the father resemble him, he must be the absolute sexual complement of the woman in question. If such cases are very rare, it is only because there is not much chance of the absolute sexual complements meeting, and this is no argument against the truth of the views of Goethe and Ibsen to which I have just referred.