Socrates says that “the unexamined life is not worth living.” He embodied that principle in his own life by questioning himself and questioning others, examining opinions and beliefs to clarify them and to see if they had valid supporting reasons.
We often hold beliefs that we haven’t really thought about, but once we do examine them, we understand them better. Sometimes we revise them because we realize we were mistaken and ought to abandon a belief for an improved one.
Socrates thought this process of examination, of really trying to discover what Justice and the Good are, both as individuals and in dialogue with others, was foundational to developing as a human being, to becoming a wise and just person, and to becoming a just society.