Free will in antiquity
In Plato's Gorgias (and in the Protagoras 345c4-e6), Socrates argues that no one does wrong willingly, one of the most famous doctrines to be associated with him. When framed in modern (Western) terms, the implication is that it is ignorance, rather that free individual agency, that is responsible for morally wrong actions.
Critical thinking
The earliest documentation of critical thinking are the teachings of Socrates recorded by Plato. Socrates established the fact that one cannot depend upon those in "authority" to have sound knowledge and insight. He demonstrated that persons may have power and high position and yet be deeply confused and irrational. He established the importance of asking deep questions that probe profoundly into thinking before we accept ideas as worthy of belief.