It’s not the content of Thales’ (c. 624–c. 545 B.C.E.) thought that proved to be so important, but rather his willingness to boldly think about the whole of physical existence. Thales’ home was Miletus, which had strong ties to Egypt. Like the Egyptians, he believed that the earth floated on water and that water or moisture was the primary substance or stuff of the world. Aristotle thought that Thales had been impressed by the importance of water and fluids for life generally. Indeed, Thales seems to have thought that life is present in every part of the universe and that it was divine; hence, he is said to have remarked, “Everything is full of gods.” Thales’ most striking and novel insight was that the movements and qualities of water could be used to explain the behavior of living things, as well as natural events. The behavior of water was, in that way, a primary moving principle (a primary moving principle was a thing that was responsible for the movement of all other things), at the same time that water was held to be the primary “stuff” of the universe.