Iron Age Greece
The Greek Philosopher Pythagoras, as described by Clement of Alexandria
c. 575–495 BC, Crotona, southern Italy.
Both Pythagoras and Plato derived their ideas from the barbarians: Egyptians and Persians; and the Druids among the Gauls; and the philosophers of the Celts.
Clement of Alexandria was born in the middle of the 2nd century AD, possibly in Athens, of non-Christian parents, and received an excellent education. He rose to become head of the early-Christian Catechetical School of Alexandria.
In the final book of his Great Trilogy, Clement of Alexandria was keen to show that the philosophy of the Greeks was rooted in the ideas of those he termed 'barbarians'. Both Pythagoras and Plato derived their ideas from the barbarians. Plato, he points out, is openly keen to admit that this is so. Philosophy flourished in barbarian lands. Numa, a King of Rome was a Pythagorean. Philosophy then found its way into Greece.
First in its ranks were the prophets of the Egyptians; and the Chaldeans among the Assyrians; and the Druids among the Gauls; and the Samanæans among the Bactrians; and the philosophers of the Celts; and the Magi of the Persians...
Clement of Alexandria, c. 150–215 AD. Great Trilogy: 3. The Stromata. Chapter XV – The Greek Philosophy in Great Part Derived from the Barbarians.