It is difficult to write about Thales, since none of his own writing survives. He was an engineer, scientist, mathematician, and philosopher, the first natural philosopher in the Milesian School. It is also thought that he was the teacher of Anaximander (611 BC - 545 BC). There are those who believe he wrote a book on navigation, but there is little evidence of such a tome. In fact, if he wrote any works at all, they did not even survive until the time of Aristotle (384 BC - 322 BC). Whether the book ever existed, Thales probably did define the constellation Ursa Minor.
Seven SagesDespite the fact that much of what is known about thalse is pure hear-say, he was definitely well respected in ancient Greece, being the only philosopher before Socrates to be among the Seven Sages.
There are reports that Thales predicted an eclipse of the Sun in 585 BC. While the 19 year cycle for Lunar eclipses was well known by this time, solar eclipses were harder to predict, since they were visible from different locations on Earth. Most likely, if he did make such a predictipon, it was a lucky guess based on experience saying that another eclipse was due.
After the eclipse on 28 May, 585 BC Herodotus wrote, "Day was all of a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on."
Impressive Bu HumanThales is often credited with some impressive work with geometry. It is said he measured the heights of pyramids by measuring their shadows and could determine the distances of ships from shore. How much of our knowledge of Thales is accurate is anyone's guess. Most of what we know is due to Aristotle who wrote in his Metaphysics: "Thales of Miletus taught that 'all things are water'." Apparently Thales believed the Earth floated in water and everything came from water.
Like the absent minded professor stereotype we know of today, Thales has been described in both glowing and derogatory tales. One story, told by Aristotle, says Thales used his skills to predict that the next season's olive crop would be bountiful. He then purchased all the olive presses and made a fortune when the prediction came true. Plato, on the other hand, told a story of how one night Thales was gazing at the sky as he walked and fell into a ditch. There was a pretty servant girl nearby who came to his rescue, then said to him "How do you expect to understand what is going on up in the sky if you do not even see what is at your feet".
Thales died about 547 BC in Miletus, Asia Minor (now Turkey).