Thales of Miletus (624 BC - 546 BC)

Thales' attempt to give a naturalist explanation of the world is regarded as the beginning of science and philosophy. His description rejects the traditional idea of a creator and states that everything in nature is a variation of an originating substance, which functions as a universal controlling force: water. For the Greek material monist, there is no distinction between the organic and the inorganic. "All things are full of gods," he says, meaning that everything encapsulates a divine element (an impersonal soul) which constitutes the motive force causing objects to move and people to act. Thales urges people to lead a just life but believes their morals have a better chance of reforming under an autocratic rule.