R. M. Bucke dedicates this book to his friend, American poet Walt Whitman, for his “exalted moral nature.” Bucke divides man’s moral nature into three parts: 1) active nature, by which he acts, 2) intellectual nature, by which he knows, and 3) moral nature proper, by which he feels. Moral nature, Bucke believes, has a physiological basis in the sympathetic nervous system (pictured opposite p. 48) and intellectual nature in the cerebral spinal system (pictured opposite p. 60). He concluds that an evolution in man’s moral nature reflects a development of his sympathetic nervous system. The signature of F. E. Perrin at front is likely that of London, Ontario resident Finley Ewart Perrin.