One’s own experience has the advantage of complete certainty and the greatest speciality, and this outweighs the disadvantage that arises from it, that its sphere is limited and its examples not generally known. Therefore, primarily, I refer every one to his own experience. First of all let him consider himself, confess to himself his inclinations and passions, his characteristic errors and weaknesses, his vices, and also his excellences and virtues, if he has any. Then let him think of his father, and he cannot fail to recognise all these characteristic traits in him also. On the other hand, he will often find his mother of an entirely different character, and a moral agreement with her will very seldom occur, indeed only through the exceptional accident of a similarity of the character of the two parents. Let him make this examination, for example, with reference to quick temper or patience, avarice or prodigality, inclination to sensuality, or to intemperance, or to gambling, hard‐ heartedness or kindliness, honesty or hypocrisy, pride or condescension, courage or cowardice, peaceableness or quarrelsomeness, placability or resentfulness, &c. Then let him make the same investigation with regard to all those whose characters and whose parents he has accurately known. If he proceeds attentively, with correct judgment, and candidly, the confirmation of our principle will not be lacking. Thus, for example, he will find the special tendency to lie, which belongs to many men, equally present in two brothers, because they have inherited it from the father; on this account also the comedy, “The Liar and his Son,” is psychologically correct. However, two inevitable limitations must here be borne in mind, which only open injustice could interpret as evasions. First, _pater semper incertus_. Only a decided physical resemblance to the father removes this limitation; a superficial resemblance, on the other hand, is not sufficient to do so; for there is an after‐effect of earlier impregnation by virtue of which the children of the second marriage have sometimes still a slight resemblance to the first husband, and children begotten in adultery to the legitimate father. Such an after‐effect has been still more distinctly observed in the case of brutes. The second limitation is, that in the son the moral character of the father certainly appears, yet under the modification which it has received through another and often very different _intellect_ (the inheritance from the mother), and thus a correction of the observation becomes necessary. This modification may be important or trifling in proportion to that difference, but it can never be so great that the fundamental traits of the paternal character do not always appear under it recognisably enough, like a man who has disguised himself by an entirely different kind of dress, wig, and beard. For example, if by inheritance from the mother a man is pre‐eminently endowed with reason, thus with the power of