It would be an impertinence for an amateur in physiological science to assert that the significance of ethical values can be understood only through a study of the mechanics of the human body, were not the ethical implications of physiology so numerous, so compelling, and so plainly apparent. Ever since anatomists and physiologists first began to demonstrate that all the vital functions of man were dependent upon his intimate structure; and more recently that conduct and thought are in the strictest sense of the term functions of man's flesh, they have been laying the foundations,--even if unconsciously,--of a scrupulously natural science of ethics. The purpose of this book is to attempt the formulation of such a science.
There is little need to state that any proposal to deal with ethics in a thoroughly naturalistic manner will be met with considerable resistance. Although it has been everlastingly recognized that human conduct is the direct product of human bodies, especially as is evidenced by our bestowal of rewards and punishments on individually specified persons,