In the spring of 585 B.C. in the Eastern Mediterranean, the moon came out of nowhere to hide the face of the sun, turning day into night.

Back then, solar eclipses were cloaked in scary uncertainty. But a Greek philosopher was said to have predicted the sun’s disappearance. His name was Thales. He lived on the Anatolian coast — now in Turkey but then a cradle of early Greek civilization — and was said to have acquired his unusual power by abandoning the gods.

The eclipse had an immediate worldly impact. The kingdoms of the Medes and Lydian had waged a brutal war for years. But the eclipse was interpreted as a very bad omen, and the armies quickly laid down their arms. The terms of peace included the marriage of the daughter of the king of Lydia to the son of the Median king.

The impiety of Thales had a more enduring impact, his reputation soaring over the ages. Herodotus told of his foretelling. Aristotle called Thales the first person to fathom nature. The classical age of Greece honored him as the foremost of its seven wise men.

Today, the tale illustrates the awe of the ancients at the sun’s disappearance and their great surprise that a philosopher knew it beforehand.

The episode also marks a turning point. For ages, eclipses of the sun were feared as portents of calamity. Kings trembled. Then, roughly 2,600 years ago, Thales led a philosophical charge that replaced superstition with rational eclipse prediction.