1910. This book is addressed to disciplined minds, and in special to biologists. As the author wrote it, he did not have the general public in his mind, and so did not hesitate to devote nearly an entire chapter to "disharmonies in the apparatus of reproduction." Contents: Part I: Disharmonies in the Nature of man: introduction, summary of opinions on the nature of man; harmonies and disharmonies amongst beings inferior to man; simian origin of man; disharmonies in the organization of the digestive system of man; disharmonies in the instinct of self-preservation; Part II: Attempts to Diminish the Ills Arising from the Disharmonies of the Human Constitution (Religious and Philosophical Systems): religious attempts to combat the ills arising from the disharmonies of the human constitution; attempts in systems of philosophy to remedy the ills arising from the disharmonies of the human constitution; Part III: What Science Is Able to Do to Alleviate the Disharmonies of the Human Constitution: what science can do against disease; introduction to the scientific study of old age; instruction to the scientific study of death.