Thales

Thales of Miletus, born around 626 to 623 BC and died around 548 to 545 BC, was a pre-Socratic Greek philosopher from Miletus in Ionia, Asia Minor, and one of the Seven Sages, founding figures of Ancient Greece. Beginning in eighteenth century historiography, many came to regard him as the first philosopher in the Greek tradition, breaking from the prior use of mythology to explain the world and instead using natural philosophy, and he is thus referred to as the first to have engaged in mathematics, science and deductive reasoning. His view that all of nature is based on the existence of a single ultimate substance, which he theorized to be water, was widely influential among the philosophers of his time, and he thought the Earth floated on water. Thales is the namesake of Thales's theorem and was said to have calculated the heights of the pyramids and the distance of ships from the shore; as an astronomer he reportedly predicted the weather and a solar eclipse. Plutarch wrote that at that time, Thales alone had raised philosophy from mere speculation to practice.