Thales of Miletus was already considered by Aristotle as the first Greek philosopher. Born around the year 624 B.C. he is today recognized as the forerunner of modern science, in the sense that he tried to explain the world through theories and hypotheses, moving away from the traditional mythological interpretation of phenomena and nature.
No writing of Thales has been preserved, it is not even known if he wrote anything in his life, but what has come to us through the sources places him at the head of the Seven Wise Men of Greece, thanks to his knowledge and contributions in philosophy, mathematics and astronomy.
It is also not known whether he was a native of Miletus (on the current Turkish coast of the Aegean) or, as Diogenes Laertius points out, he came from Phenicia where his parents were from. But what is certain is that in Miletus he was respected for his wisdom, and both Ionians and Lydians came to him for political advice.
We already told here how he predicted the solar eclipse of the year 585 BC, which surprised the Medes and Lydians in the middle of the battle of the Halis River. Herodotus affirms (without giving him much truth) how the Lydian king Croesus had turned to Thales so that his army could cross the river, whose abundant flow made it impossible to ford:
Today historians do not completely rule out the veracity of this story. Thales had the necessary knowledge for it and, as we said, he was usually required as an adviser by kings and cities.
But despite his fame, he was not exempt from criticism from his fellow citizens. Thales was not a wealthy man, but neither was he in dire need. He probably lived in a simple way engaged in his investigations without taking care of material matters. We have proof of this in what Aristotle says:
In order to show that philosophers could easily get rich if that was his goal, Thales used his knowledge to predict that the following summer there would be a great olive harvest. With a little money he had saved he leased all the oil presses in Chios and Miletus cheaply in advance, since no one else bid for them.
When harvest time came and the Milesian peasants came to press their olives, they found that Thales relet the presses to them at much higher prices.
In this way he managed to make a small fortune. This would be the first historical mention of the creation and use of options (a type of contract that gives the buyer the right, but not the obligation, to sell or buy goods at a price agreed in advance at a future date).
According to another version, Tales would not have reserved the presses but would have bought them. This fact would constitute the first documented occasion of the creation and use of futures contracts (Agreements that oblige the contracting parties to buy or sell a certain number of goods on a future date at a price agreed in advance).
For Aristotle things were very clear:
They say that the Milesians, recognizing the wisdom of Thales, congratulated him on his sagacity, but Thales, receiving his congratulations with a smile, returned to his usual and simple way of life. Never again did anyone suggest that he cultivated virtue because he was too foolish to succeed in worldly affairs .