Definition for Thales
From Biology Forums Dictionary
Thales (? to 555 B.C.E.): Greek natural philosopher, regarded as the first philosopher, born in Miletus. His journeys took him to Egypt and Babylon, where he acquired land-surveying and astronomical techniques, and apparently predicted the solar eclipse in 585 BC. None of his writings are extant, but Aristotle credits him with the doctrine that water is the original substance (Arche) from which all things are derived. Diogenes Laertius tells a fanciful tale of his meteorological prowess being used to amass a fortune in the olive oil business—not, as Thales says there, because wealth is desirable inherently, but to show that a wise man could be rich, if he so chose.