The general characterisation of the ideal woman, “W,” is followed by the construction of individual types, which are finally resolved into two elemental figures (Platonic conceptions to some extent), the Courtesan and the Mother. These are differentiated by their pre-occupation with the sexual act (the main, and in the ultimate sense, sole interest of “W”), in the first case, as an end in itself, in the second as the process which results in the possession of a child. The abnormal type, the hysterical woman, leads up to a masterly psychological (not physiological) theory of hysteria, which is acutely and convincingly defined as “the organic mendacity of woman.” Weininger himself attached the highest importance to the ethico-philosophical chapters that conclude his work, in which he passes from the special problem of sexuality to the problems of individual talent, genius, æsthetics, memory, the _ego_, the Jewish race, and many others, rising finally to the ultimate logical and moral principles of judgment. From his most universal standpoint he succeeds in estimating woman as a part of humanity, and, above all, subjectively. Here he deliberately comes into sharp conflict with the fashionable tendencies towards an unscientific monism and its accompanying phenomena, pan-sexuality and the ethics of species, and characterises very aptly the customary superficialities of the many non-philosophical modern apostles, of whom Wilhelm Bölsche and Ellen Key are perhaps the most representative types. Weininger, in defiance of all reigning fashions, represents a consolidated dualism, closely related to the eternal systems of Plato, of Christianity, and of Kant, which finds an original issue in a bitterly tragic conception of the universe. Richard Wagner (whom Weininger calls the greatest of human beings after Jesus) gives artistic expression in his _Parsifal_ to the conception Weininger sets forth scientifically. It is, in fact, the old doctrine of the divine life and of redemption to which the whole book, with its array of detail, is consecrated. In Kundry, Weininger recognises the most profound conception of woman in all literature. In her redemption by the spotless Parsifal, the young philosopher sees the way of mankind marked out; he contrasts with this the programme of the modern feminist movement, with its superficialities and its lies; and so, in conclusion, the book returns to the problem, which, in spite of all its wealth of thought, remains its governing idea: the problem of the sexes and the possibility of a moral relation between them--a moral relation fundamentally different from what is commonly understood by the term, of course. In the two chapters: “The Nature of Woman and her significance in the Universe,” and “Woman and Mankind,” we drink from a fountain of the ripest wisdom. A tragic and most unhappy mind reveals itself here, and no thoughtful man will lay down this book without deep emotion and