When the author finally decided to write the counterpart of “Woman”, it occurred to him that if the amatory emotions are the same in men and women, they ought to be treated together in one volume. Hence the present work “Love, A Treatise on the Science of Sex-Attraction.” Naturally the present volume recapitulates all that the author has previously written in his three books, “Woman,” “Genesis,” and “Neurasthenia Sexualis.” The three previous works are mere chapters of the present treatise. Still every author grows with his work. After years of study of the subject of sex, he was able to expand the sphere of his previous lessons, so that even those readers who have read his three previous books will still find some new points in this work. If the readers should agree with this opinion, the author will consider himself well paid for his labors. THE AUTHOR. New York, May, 1915. PREFACE TO SECOND EDITION The main criticism of “Love” by the reviewers of the first edition was directed against the frequency of Latin words and phrases used in veiling some of the more unpleasant aspects of the normal and especially the pathological sex-activities. Still it was not prudery which dictated this course. The ancient language was used as a protection against the criticism of those who would take umbrage to plain sex expressions. There is quite a number of people who are not only possessed of the Oedipus complex or the Electra complex, but who are also obsessed of the obscenity complex. For the impure everything is impure. Fortunately such people’s knowledge of Latin is, as a rule, very slight, and for them this treatise will remain a sealed book. Physicians and lawyers for whom this book was written know enough Latin grammar, enabling them to apprehend the meaning of all those phrases necessary for the understanding of the main points of the treatise. To facilitate the reader’s task the following vocabulary of the Latin words often used has been appended.