White Innocence
In his letter to his nephew, Baldwin first brings up the ironic fact that white people are most guilty for their presumed innocence. By this, he means that white insistence on innocence is even more harmful than white mistreatment of African Americans, because it allows them to deny the reality of their situation and continue their pattern of behavior. If white people continue to feel innocent of any crime, then they will not change their ways. But it is ironic that Baldwin would refer to their "innocence" as their "greatest crime."
Violence as a Means of Gaining White Respect
Baldwin explains that, for many of his peers, the best way to intimidate white people and thereby gain some measure of respect or power in their society was to make use of violence. It is ironic that the only way black people could achieve better treatment or respect from white people was through violence, because it was precisely black violence that white people most feared and claimed as one of the reasons for black inferiority. However, because white people left them few other options for improving their lot other than turning to violence, it was they who turned many of Baldwin's peers toward this violent path.
God as Savior
Over time, Baldwin came to recognize that his Christian faith was too full of irony to sustain him any longer. He realized that Christianity purported to offer salvation to everyone, including black people, by building a relationship for them with God. However, Baldwin leans that the Christian God is presumed to be a white one, who favors white people over black people. He recognizes a kind of irony in the expectation that black people be saved and fulfilled by a force that assumes them to be inferior.
Beauty in Suffering
Baldwin notes at the end of his second essay that some of the greatest beauty he sees in the world has come out of black suffering. Ironically, black people are able to find a certain kind of beauty in the world precisely because they have experienced so much ugliness and pain. This is a kind of beauty that Baldwin believes white people are unable to see because they have been on the other side of this pain, perpetuating it, instead of feeling it themselves. It is thus up to black people to teach their oppressors how to see the beauty to which they have access only to as a consequence of this repression—an ironic situation to find themselves in.