The Politics,c. 330 BC
It would be well to collect the scattered stories of the ways in which individuals have succeeded in amassing a fortune, for all this is useful to persons who value the art of making money. There is the anecdote of Thales the Milesian and his financial device, which involves a principle of universal application but is attributed to him on account of his reputation for wisdom. He was reproached for his poverty, which was supposed to show that philosophy was 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 capital, he gave earnest money 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 wanted them 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. He is supposed to have given a striking proof of his wisdom, but, as I was saying, his device for getting money is of universal application, and is nothing but the creation of a monopoly. It is an art often practiced by cities when they are in want of money; they make a monopoly of provisions.