Thales bet that everything is made of water and started philosophy doing it
Around 600 BC Thales of Miletus tried explaining the world through natural causes instead of the whims of gods. He guessed that water underlies everything and that the Earth floats on it. Wrong, but the move from myth to reasoned hypothesis is why many historians call him the first Greek philosopher.
Nearly everything about his life comes from Diogenes Laërtius, who wrote some eight centuries later and relied on sources that were sometimes invented. Thales came from Miletus, a trading port where the Maeander River met the sea, close to present-day Didim in Turkey. Herodotus says he foretold a solar eclipse in 585 BC, and a later chronicler used that event to place his birth around 625 BC. Herodotus also called him Phoenician by remote descent, though most ancient writers treated him as a well-born native Milesian.
Tradition credits him with a remarkable range of feats: working out the height of the pyramids and the distance of ships at sea, locating Ursa Major, timing the solstices, and helping a Lydian army cross the Halys River. Geometry has a theorem in his name. Whether he learned mathematics in Egypt or Babylonia is disputed; later writers routinely sent famous thinkers on eastern journeys to explain their knowledge.
He was counted among the Seven Sages, alongside Solon and others, and is linked to the Delphic motto know thyself. One tale has a golden bowl bequeathed to the wisest man; it passed to Thales, travelled round all the sages and came back, and he dedicated it to Apollo. Asked by Solon why he stayed single, he supposedly said he did not want the worry of children.
His water thesis survives through Aristotle, who named Thales the founder of natural philosophy and guessed at his reasons: food is moist, seeds are moist, and heat seems to depend on moisture. Aristotle's reasoning was his own, but the claim itself is accepted as genuinely Thales's. That view of him as the first philosopher only became mainstream among eighteenth-century historians.
Source: Thales of Miletus
