Thales of Miletus (c. 624–c. 546 B.C.E.) was an ancient Greek natural philosopher, cosmologist, astronomer, and mathematician. He has been credited as being the founder of natural philosophy (and philosophy in general) as well as geometry.
Thales, according to Herodotus, was, "a man of Miletus, of Phoenician descent". Miletus was an important Greek city state in the region called Ionia, on the west coast of Asia Minor. The Phoenicians were an ancient Levantine seafaring people. Thales' possible descent from a seafaring people gives a possible clue as to the origin of Thales' studies. The stars have been used for navigation since time immemorial, and Thales is alleged to have written a book entitled Nautical Astronomy. It is thus plausible that a nautical background led Thales to study astronomy, and this in turn led to considerations of cosmology, geometry, and natural philosophy.