One of the first authors who thus endowed non-human objects with human feelings was the Greek philosopher Empedokles, who flourished about twenty-three centuries ago. Just as the last of the great German metaphysicians, Schopenhauer, believed that all the forces of Nature—astronomic, chemical, biological, etc.—are identical with the human Will, of which they represent different stages of development or “objectivation,” so Empedokles insisted that the two ruling passions of the human soul, Love and Hate, are the two principles which pervade and rule the whole universe. In the primitive condition of things, he taught, the four elements, Earth, Water, Air, and Fire are mingled harmoniously, and Love rules supreme. Then Hate intervenes and produces individual, separate forms. Plants are developed, and after them animals, or rather, at first, only single organs—detached eyes, arms, hands, etc. Then Love reasserts its force and unites these separate organs into complete animals. Strange monstrosities are the result of some of these unions—animals of double sex, human heads on the bodies of oxen, or horned heads on the bodies of men. These, however, perish, while others, which are congruous and adapted to their surroundings, survive and multiply. Thus Empedokles, “the Greek Darwin,” was the originator of a theory of evolution based on the alternate predominance of cosmic Love and Hate; Love being the attractive, Hate the repulsive force. In the preface to the first volume of _Don Quixote_, Cervantes refers those who wish to acquire some information concerning Love to an Italian treatise by Judah Leo. The full title of the book, which appeared in Rome in the sixteenth century, is _Dialoghi di amore, Composti da Leone Medico, di nazione Ebreo, e di poi fatto cristiano_. There are said to be three French translations of it, but it was only after long searching that I succeeded in finding a copy, at the Bibliothèque Nationale in Paris. It proved to be a strange medley of astrology, metaphysics, theology, classical erudition, mythology, and mediæval science. Burton, in the chapter on Love, in his _Anatomy of Melancholy_, quotes freely from this work of Leo, whom he names as one of about twenty-five authors who wrote treatises on Love in ancient and mediæval times. Like Empedokles, Leo identifies cosmic attraction with Love. But he points out three degrees of Love—Natural, Sensible, and Rational. By Natural Love he means those “sympathies” which attract a stone to the earth, make rivers flow to the sea, keep the sun, moon, and stars in their courses, etc. Burton (1652) agrees with Leo, and asks quaintly, “How comes a loadstone to draw iron to it ... the ground to covet showers, but for love? ... no stock, no stone, that has not some feeling of love. ’Tis more eminent in Plants, Hearbs, and is especially observed in vegetals; as betwixt the Vine and Elm a great sympathy,” etc.