as for a material cause; in other words, when he asked not only of what elements the world is composed, but also by what forces were they brought together. He tells us of two such causes, Love and Strife, the one a combining, the other a dissociating power. If for these half-mythological names we read attractive and repulsive forces, the result will not be very different from our own current cosmologies. Such terms, when so used as to assume the existence of occult qualities in matter, driving its parts asunder or drawing them close together, are, in truth, as completely mythological as any figments of Hellenic fancy. Unlike their modern antitypes, the Empedoclean goddesses did not reign together, but succeeded one another in alternate dominion during protracted periods of time. The victory of Love was complete when all things had been drawn into a perfect sphere, evidently the absolute Eleatic Being subjected to a Heracleitean law of vicissitude and contradiction. For Strife lays hold on the consolidated orb, and by her disintegrating action gradually reduces it to a formless chaos, till, at the close of another world-period, the work of creation begins again. Yet growth and decay are so inextricably intertwined that Empedocles failed to keep up this ideal separation, and was compelled to admit the simultaneous activity of both powers in our everyday experience, so that Nature turns out to be composed of six elements instead of four, the mind which perceives it being constituted in a precisely similar manner. But Love, although on the whole victorious, can only gradually get the better of her retreating enemy, and Nature, as we know it, is the result of their continued conflict. Empedocles described the process of evolution, as he conceived it, in somewhat minute detail. Two points only are of much interest to us, his alleged anticipation of the Darwinian theory and his psychology. The former, such as it was, has occasionally been attributed to Lucretius, but the Roman poet most probably copied Epicurus, although the very brief summary of that philosopher’s physical system preserved by Diogenes Laertius contains no allusion to such a topic. We know, however, that in Aristotle’s time a theory identical with that of Lucretius was held by those who rejected teleological explanations of the world in general and of living organisms in particular. All sorts of animals were produced by spontaneous generation; only those survived which were accidentally furnished with appliances for procuring nourishment and for propagating their kind. The notion itself originated with Empedocles, whose fanciful suppositions have already been mentioned in a different connexion. Most assuredly he did not offer it as a solution of problems which in his time had not yet been mooted, but as an illustration of the confusion which prevailed when Love had only advanced a little way in her ordering, harmonising, unifying task.