Regarding the treatise on the "science of society" (for he had decided to call it that instead of "sociology") mentioned in the Preface, it should be said that Professor Sumner left a considerable amount of manuscript in the rather rough form of a first draft, together with a great mass of classified materials. He wrote very little on this treatise after the completion of _Folkways_, and not infrequently spoke of the latter to the present writer as "my last book." It is intended, however, that the _Science of Society_ shall be, at some time in the future, completed, and in such form as shall give to the world the fruits of Professor Sumner's intellectual power, clarity of vision, and truly herculean industry. The present revision of _Folkways_ incorporates but few and unimportant corrections. Certain of these are from the hand of the author, and others from that of the present writer. A photograph of Professor Sumner has been chosen for insertion in the present edition. It was taken April 18, 1902, and is regarded by many as being the most faithful representation in existence of Sumner's expression and pose, as he appeared in later years. This is the Sumner of the "mores," with mental powers at ripe maturity and bodily vigor as yet unimpaired by age. The Yale commencement orator of 1909 said of Sumner, in presenting him for the Doctorate of Laws: "His intellect has broadened, his heart has mellowed, as he has descended into the vale of years." While advancing age weakened in no respect the sheer power and the steady-eyed fearlessness of mind and character which made Sumner a compelling force in the university and in the wider world, it seems to some of us that the essential kindliness of his nature came out with especial clearness in his later years. And it is the suggestion of this quality which lends a distinctive charm, in our eyes, to the portrait chosen to head this volume. A. G. KELLER YALE UNIVERSITY CONTENTS CHAPTER PAGE I. FUNDAMENTAL NOTIONS OF THE FOLKWAYS AND OF THE MORES 1 II. CHARACTERISTICS OF THE MORES 75 III. THE STRUGGLE FOR EXISTENCE 119 IV. LABOR, WEALTH 158 V. SOCIETAL SELECTION 173 VI. SLAVERY 261 VII. ABORTION, INFANTICIDE, KILLING THE OLD 308 VIII. CANNIBALISM 329 IX. SEX MORES 342 X. THE MARRIAGE INSTITUTION 395 XI. THE SOCIAL CODES 417 XII. INCEST 479