Thus it was that in the midst of a people who worshipped traditionally a multitude of gods and goddesses, such as we have them exhibited in the Homeric and Hesiodic poems, the chief, perhaps the only, and the yet unwritten literature of that day, beings with a personal character and will, who were supposed to divide the government of the world between them, with a more or less recognised sovereignty of one chief, arose men who set themselves by the light of reason to think steadily and continuously how that world in which they were living had become what it was. Such a movement of mind indicated in itself dissatisfaction with the existing religion, wherein the gods were considered the causes of things, and their wills the rulers of them, though in the background even here loomed the idea of fate, the representative, as it were, of brute matter, from which the Greek mind could never disengage itself. Yet we do not find that these philosophers set themselves openly to attack the existing religion; rather leaving it in possession, and themselves usually complying with its forms, they pursued their own train of thought, as it were by its side, not choosing to look whither it would lead them.
Such very much appears the position of inquirers in the first period of Greek philosophy, which is generally made to extend from its rise under Thales to the time of the Sophists and Socrates. Their thoughts were mainly occupied with the appearances of the physical world: they speculated how it could have arisen. Thus Thales, we are told, imagined its first principle to be water; Anaximander, boundless matter; Anaximenes, air; the Pythagoreans said, all is number; the Eleatic school, all is the one unchangeable being.(328) On the contrary Heracleitus conceived the one Being as ever in motion, involved in perpetual change: in accordance with which he nowhere finds true knowledge, and thinks the mass of men have no understanding for eternal truth.(329) Empedocles of Agrigentum sets forth the four elements, earth, water, air, and fire, as the material principles or roots of things, attaching to these two ideal principles as moving forces, Love as the unitive, and Hatred as the severing.(330) Anaxagoras, over and above mechanical causes, to which he limited himself in the explanation of everything in particular, recognises a divine spirit, which as the finest of all things is simple, unmixed, passionless reason, which came upon chaos, forming and ordering the world out of it.(331) Democritus of Abdera takes for his principles the Full and the Empty, identifying these with Being and Non-being, or Something and Nothing. His Full consists of indivisible atoms.(332)