Empedocles of Agrigentum, a sort of magician and high-priest, almost a deity, whose life and death are but little known, appears to have possessed an encyclopaedic brain. From him is derived the doctrine of the four elements, for whereas the philosophers who preceded him gave as the sole source of things--some water, others air, others fire, others the earth, he regarded them all four equally as the primal elements of everything. He believed that the world is swayed by two contrary forces--love and hate, the one desiring eternally to unite, the other eternally to disintegrate. Amid this struggle goes on a movement of organization, incessantly retarded by hate, perpetually facilitated by love; and from this movement have issued--first, vegetation, then the lower animals, then the higher animals, then men. In Empedocles can be found either evident traces of the religion of Zoroaster of Persia (the perpetual antagonism of two great gods, that of good and that of evil), or else a curious coincidence with this doctrine, which will appear again later among the Manicheans. PYTHAGORAS.--Pythagoras appears to have been born about B.C. 500 on the Isle of Elea, to have travelled much, and to have finally settled in Greater Greece (southern Italy). Pythagoras, like Empedocles, was a sort of magician or god. His doctrine was a religion, the respect with which he was surrounded was a cult, the observances he imposed on his family and on his disciples were rites. What he taught was that the true realities, which do not change, were numbers. The fundamental and supreme reality is _one_; the being who is one is God; from this number, which is one, are derived all the other numbers which are the foundation of beings, their inward cause, their essence; we are all more or less perfect numbers; each created thing is a more or less perfect number. The world, governed thus by combinations of numbers, has always existed and will always exist. It develops itself, however, according to a numerical series of which we do not possess the key, but which we can guess. As for human destiny it is this: we have been animated beings, human or animal; according as we have lived well or ill we shall be reincarnated either as superior men or as animals more or less inferior. This is the doctrine of _metempsychosis_, which had many adherents in ancient days, and also in a more or less fanciful fashion in modern times. To Pythagoras have been attributed a certain number of maxims which are called the _Golden Verses_. XENOPHANES; PARMENIDES.--Xenophanes of Colophon is also a "unitarian." He accepts only one God, and of all the ancient philosophers appears to be the most opposed to mythology, to belief in a multiplicity of gods resembling men, a doctrine which he despises as being immoral. There is one God, eternal, immutable, immovable, who has no need to transfer Himself from one locality to another, who is _without place_, and who governs all things by His thought alone.