Ancient Skeptic philosophers

Xenophanes of Colophon ( ; ; – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer. He was born in Ionia and travelled throughout the Greek-speaking world in early classical antiquity.

Pyrrho of Elis (; ; ) was a Greek philosopher of Classical antiquity, credited as being the first Greek skeptic philosopher and founder of Pyrrhonism.

Greek Pyrrhonist philosopher (c.320–c.235 BC)

Anaxarchus (; ; c. 380 – c. 320 BC) was a Greek philosopher of the school of Democritus. Together with Pyrrho, he accompanied Alexander the Great into Asia. The reports of his philosophical views suggest that he was a forerunner of the Greek skeptics.

4th-century BC Greek philosopher

Nausiphanes (; lived c. 325 BC) was an ancient Greek atomist philosopher from Teos.

Xeniades () was a skeptical philosopher from Corinth, probably a follower of the pre-Socratic Xenophanes. There may have been two such persons, as he is referenced by Democritus c. 400 BC, though was also supposedly the purchaser of Diogenes the Cynic c. 350 BC, when he was captured by pirates and sold as a slave. Xeniades was supposed to have been the man who persuaded Monimus to become a follower of Diogenes, and was the source of his skeptical doctrines.

6th-century BCE Indian ascetic teacher