I believe that we are justified in asserting that at the present time the sexual differentiation manifested in respect of quite a number of psychical qualities is the result of direct inheritance. It would be quite wrong to assume that all these differences arise in each individual in consequence of education. It does, indeed, appear to me to be true that inherited tendencies may be increased or diminished by individual education; and further, that when the inherited tendency is not a very powerful one, it may in this way even be suppressed. We must not forget the frequent intimate association between structure and function. Rough outdoor games and wrestling thus correspond to the physical constitution of the boy. So, also, it is by no means improbable that the little girl, whose pelvis and hips have already begun to indicate by their development their adaption for the supreme functions of the sexually mature woman, should experience obscurely a certain impulsion toward her predestined maternal occupation, and that her inclinations and amusements should in this way be determined. Many, indeed, and above all the extreme advocates of women's rights, prefer to maintain that such sexually differentiated inclinations result solely from differences in individual education: if the boy has no enduring taste for dolls and cooking, this is because his mother and others have told him, perhaps with mockery, that such amusements are unsuited to a boy; whilst in a similar way the girl is dissuaded from the rough sports of boyhood. Such an assumption is the expression of that general psychological and educational tendency, which ascribes to the activity of the will an overwhelmingly powerful influence upon the development of the organs subserving the intellect, and secondarily also upon that of the other organs of the body. We cannot dispute the fact that in such a way the activity of the will may, within certain limits, be effective, especially in cases in which the inherited tendency thus counteracted is comparatively weak; but only within certain limits. Thus we can understand how it is that in some cases, by means of education, a child is impressed with characteristics normally foreign to its sex; qualities and tendencies are thus developed which ordinarily appear only in a child of the opposite sex. But even though we must admit that the activity of the individual may operate in this way, none the less we are compelled to assume that certain tendencies are inborn. The failure of innumerable attempts to counteract such inborn tendencies by means of education throws a strong light upon the limitations of the activity of the individual will; and the same must be said of a large number of other experiences.