It’s possible that there were others before him, but we have no evidence of them. So most historians are content to say that philosophy began with Thales.
To be sure, there are alternative views. A more modest, and almost universally accepted claim, is that Greek philosophy began with Thales. That allows for Hebrew or Sanskrit thinkers who may have philosophized a few centuries earlier.
Greek philosophy continued for the next 150 years or so, filling the ‘pre-Socratic’ era. Many of this first wave of Greek philosophers did not live in Greece, but rather in Greek settlements on islands in the Mediterranean, in southern Italy, or in Ionia. (Ionia is a western coastal region in Turkey.)
The pre-Socratic philosophers explored topics often related to time, space, mathematics, and physics. They were interested in cosmology and logic.
The focus and location of Greek philosophy would change.
Geographically, this second wave of Greek philosophers - the ‘classical’ philosophers - would be located in Greece.
In terms of their content, these classical thinkers turned away from the abstract topics of pure philosophy and toward social, political, moral, and ethical matters.
This trend began with Socrates. He’d been a soldier in the Peloponnesian War (431 to 404 B.C.). The war and the political rhetoric surrounding the war posed problematic questions.
Cognitive dissonance arose from ethically questionable Athenian actions: extorting cash and goods from other Greek city-states.
Following Socrates, Plato and Aristotle would also wrestle with such questions.
In the ‘classical’ era, philosophers addressed questions about justice and about an ideal society. The problems of the time lured them away from the more disciplined and less dramatic questions of the pre-Socratics.
