In the following pages the attempt is made to connect, on a psychological basis, extremes, which as early as the time of Socrates were felt to be in vital relationship with each other. In modern times, Schopenhauer may be said to have treated the metaphysics of the subject, but its psychology, despite the increasing interest in each of the terms involved, has heretofore been neglected. The present article bases the connection on the one hand, the equivalence and interchangeability on the other, of the sexual passions (including the Anger-Fears) and the more intellectual instincts of Art, Religion, and the interests and enthusiasms generally, upon the fundamental quality of erethism found in every animal cell. The psychological expression of this bodily state is traced from its simplest manifestation, through animal combat and courting, the courting of the lower races, and the ensuing and accompanying religious, dramatic, and otherwise symbolic phenomena of Phallicism (all to be regarded as essentially subdivisions of courting) to the more complex conditions of modern times. Sexual perversions are regarded as atavistic degenerations, failures, or fetishisms of the psychological laws of courting. Modern art is represented as being the psychical expression of an erethism which is an equivalent, and historically a derivative, of that of sex; and as being therefore an overflow of some of the deepest emotions as well as a product of the intellectual capacities. A plea is thus entered for the emphasis of those activities which will form the noblest and most natural irradiations of this plastic and variable passion of sex. A full portrayal of the facts which support this view has not been possible within the limits of a single article. References are, however, made in sufficient number, it is hoped, to enable the reader to complete the picture by efforts of his own.