How does the author suggest his nephew perceive the "details and symbols of your life" in "My Dungeon Shook"?

Baldwin claims that the "details and symbols of your life have been deliberately constructed to make you believe what white people say about you." He goes on to say, "Please try to remember that what they believe, as well as what they do and cause you to endure, does not testify to your inferiority but to their inhumanity and fear."