Thales

Circa 625-Circa547 b.c.e

Philosopher

Source

Mystery. Thales of Miletus lived and worked in the prosperous port city of Miletus on the coast of Asia Minor. Tradition credits him with a variety of ingenious solutions to practical problems, but Thales left no writings to posterity. Much of what is known about him comes from Aristotle, who regarded him as the first real phusiologos or natural scientist. Thales held that water was the basic building block of all matter.

Achievements. Thales allegedly visited Egypt, where he is supposed to have learned geometry, studied the rise and fall of the Nile, and determined the height of pyramids by measuring their shadows. He is said to have designed a canal that split the deep Lydian river Halys in two, diverting some of its flow into another channel so that the army of Croesus could safely cross it. His prediction of a solar eclipse in the year 585 b.c.e. was well known in the ancient world. When mocked on account of his poverty, he is said to have noted by observing the stars that there would be a large crop of olives at the next harvest. Thales then borrowed money from friends and used it to buy up all the olive presses in Miletus. When harvest arrived and the demand for presses was high, he rented them out at many times their original purchase price and thus made a large profit. Aristotle, who tells this story, states that it proves that philosophers could be rich if they wanted to, but they are not really interested in money.

Source

G. E. R. Lloyd, Early Greek Science: Thales to Aristotle (New York: Norton, 1970).