The author in this interestingly written book confesses candidly that it is probably impossible to predict with complete objectivity the future of such a delicate matter as sex morality. He compromises, therefore, by admitting that his own wishes enter into his prediction and by at the same time giving reasons in support of them. The book, nevertheless, appears to be unduly personal in tone and to disdain the help that many branches of science are in a position to proffer. Freud's name, for example, appears nowhere in the book nor are the findings of psycho-analysis referred to, although such a book would not have been written had they never been made. When, for instance, the author asserts that 'the sex-impulse is a force of such intensity that it cannot be suppressed without causing deep psychological effects', he goes no further into the matter. Again, when in discussing whether there is a natural instinct against incest he descants on the artificial prejudice against it and adds that 'this