Thales of Miletus has some claim to being the very earliest philosopher in the Greek world. He is famous for his claim that everything is made of water. As well as being a philosopher, he was an engineer, an astronomer, and an astute observer of the natural world.
Philosophy for the insatiably curious
Socrates lived in Athens in the 5th Century BCE. He was the archetypal philosopher: a restless seeker after wisdom, a thorn in the side of the intelligentsia of Athens, a copious drinker, and a thinker who claimed that when it came down to it, he knew nothing at all.