In all history, nothing is so surprising or so difficult to account for as the sudden rise of civilization in Greece. Much of what makes civilization had already existed for thousands of years in Egypt and in Mesopotamia, and had spread thence to neighbouring countries. But certain elements had been lacking until the Greeks supplied them. What they achieved in art and literature is familiar to everybody, but what they did in the purely intellectual realm is even more exceptional. They invented mathematics and science and philosophy; they first wrote history as opposed to mere annals; they speculated freely about the nature of the world and the ends of life, without being bound in the fetters of any inherited orthodoxy. What occurred was so astonishing that, until very recent times, men were content to gape and talk mystically about the Greek genius. It is possible, however, to understand the development of Greece in scientific terms, and it is well worth while to do so.
Philosophy begins with Thales, who, fortunately, can be dated by the fact that he predicted an eclipse which, according to the astronomers, occurred in the year 585 B.C. Philosophy and science—which were not originally separate—were therefore born together at the beginning of the sixth century.
...In every history of philosophy for students, the first thing mentioned is that philosophy began with Thales, who said that everything is made of water. This is discouraging to the beginner, who is struggling—perhaps not very hard—to feel that respect for philosophy which the curriculum seems to expect. There is, however, ample reason to feel respect for Thales, though perhaps rather as a man of science than as a philosopher in the modern sense of the word.
Thales was a native of Miletus, in Asia Minor, a flourishing commercial city, in which there was a large slave population, and a bitter class struggle between the rich and poor among the free population. "At Miletus the people were at first victorious and murdered the wives and children of the aristocrats; then the aristocrats prevailed and burned their opponents alive, lighting up the open spaces of the city with live torches." Similar conditions prevailed in most of the Greek cities of Asia Minor at the time of Thales.
Miletus, like other commercial cities of Ionia, underwent important economic and political developments during the seventh and sixth centuries. At first, political power belonged to a land-owning aristocracy, but this was gradually replaced by a plutocracy of merchants. They, in turn, were replaced by a tyrant, who (as was usual) achieved power by the support of the democratic party. The kingdom of Lydia lay to the east of the Greek coast towns, but remained on friendly terms with them until the fall of Nineveh ( 612 B.C.). This left Lydia free to turn its attention to the West, but Miletus usually succeeded in preserving friendly relations, especially with Croesus, the last Lydian king, who was conquered by Cyrus in 546 B.C. There were also important relations with Egypt, where the king depended upon Greek mercenaries, and had opened certain cities to Greek trade. The first Greek settlement in Egypt was a fort occupied by a Milesian garrison; but the most important, during the period 610-560 B.C., was Daphnae. Here Jeremiah and many other Jewish refugees took refuge from Nebuchadrezzar (Jeremiah 43:5 ff); but while Egypt undoubtedly influenced the Greeks, the Jews did not, nor can we suppose that Jeremiah felt anything but horror towards the sceptical Ionians.
As regards the date of Thales, the best evidence, as we saw, is that he was famous for predicting an eclipse which, according to the astronomers, must have taken place in 585 B.C. Other evidence, such as it is, agrees in placing his activities at about this time. It is no proof of extraordinary genius on his part to have predicted an eclipse. Miletus was allied with Lydia, and Lydia had cultural relations with Babylonia, and Babylonian astronomers had discovered that eclipses recur in a cycle of about nineteen years. They could predict eclipses of the moon with pretty complete success, but as regards solar eclipses they were hampered by the fact that an eclipse may be visible in one place and not in another. Consequently they could only know that at such and such a date it was worth while to look out for an eclipse, and this is probably all that Thales knew. Neither he nor they knew why there is this cycle.
Thales is said to have travelled in Egypt, and to have thence brought to the Greeks the science of geometry. What the Egyptians knew of geometry was mainly rules of thumb, and there is no reason to believe that Thales arrived at deductive proofs, such as later Greeks discovered. He seems to have discovered how to calculate the distance of a ship at sea from observations taken at two points on land, and how to estimate the height of a pyramid from the length of its shadow.
Many other geometrical theorems are attributed to him, but probably wrongly. He was one of the Seven Wise Men of Greece, each of whom was specially noted for one wise saying; his, according to tradition, was "water is best."
According to Aristotle, he thought that water is the original substance, out of which all others are formed; and he maintained that the earth rests on water. Aristotle also says of him that he said the magnet has a soul in it, because it moves the iron; further, that all things are full of gods.
The statement that everything is made of water is to be regarded as a scientific hypothesis, and by no means a foolish one. Twenty years ago, the received view was that everything is made of hydrogen, which is two thirds of water. The Greeks were rash in their hypotheses, but the Milesian school, at least, was prepared to test them empirically. Too little is known of Thales to make it possible to reconstruct him at all satisfactorily, but of his successors in Miletus much more is known, and it is reasonable to suppose that something of their outlook came from him. His science and his philosophy were both crude, but they were such as to stimulate both thought and observation.
There are many legends about him, but I do not think more is known than the few facts I have mentioned. Some of the stories are pleasant, for instance, the one told by Aristotle in his Politics: "He was reproached for his poverty, which was supposed to show that philosophy is of no use. According to the story, he knew by his skill in the stars while it was yet winter that there would be a great harvest of olives in the coming year; so, having a little money, he gave deposits for the use of all the olive-presses in Chios and Miletus, which he hired at a low price because no one bid against him. When the harvest time came, and many were wanted all at once and of a sudden, he let them out at any rate which he pleased, and made a quantity of money. Thus he showed the world that philosophers can easily be rich if they like, but that their ambition is of another sort."
The History of Western Philosophy, Bertrand Russell, chapter 2