I am glad you brought up Plato for a couple of issues I take merit with. First, what Plato’s argument is missing is the fact that like all of us he was brought up in a civilization like us all and he was raised to their customs, laws, politics, religion, views and influences and like us all he was educated to some degree within that civilization, specifically by Socrates. So Plato was already a prisoner of the unconscious bonds of his own culture, which inevitably bias his perceptions of, and reactions to the world.
Cultural