In Invisible Man, race is a tool of characterization because it shapes a character's identity. Prior to the Civil War, this was even more true: if you were black, you were a slave. Since Invisible Man is set in the days after slavery and before the Civil Rights movement had gained momentum, race in the novel is based on the historic fact of race relations at the time – namely, that being black determined how far you could rise. Invisible Man makes a more complex argument, however. While it takes race and racism as a central fact of American life, it points to the idea of race as another category preventing us from seeing ourselves and each other as human beings. Race thus functions in the novel as the primary determinant of which stereotype is inflicted upon the characters.
Reverend Barbee is blind and Brother Jack is half-blind, indicating not only the flawed nature of their actual vision, but also the flawed nature of their vision of the world.
Thoughts and opinions are used to characterize the differences between the narrator and the Brotherhood, most notably, in their argument over Brother Clifton's funeral. Where the narrator takes an individual and personal approach to social change and relations with others, the Brotherhood prides itself on being scientific, cold, abstract, and focused on the collective rather than the individual.
Brother Tod Clifton is the only character that dies in the novel, and in German, his first name means "death." As for other significant names, "Trueblood" sounds suspect to us – what do you think? Lastly, there's the case of the narrator. We never learn either his real name or his fake Brotherhood name, which could just be a commentary on his dislike of labels. Or Ellison is really pushing us to interrogate what identity means? Which leaves us with the ubiquitous question: who is this narrator, anyway?
One more interesting use of names in Invisible Man is the name "Emerson" for the man the narrator met just prior to finding a job at Liberty Paints. In real life, author Ralph Ellison was actually born Ralph Waldo Ellison, named by his father after the American philosopher Ralph Waldo Emerson. In Invisible Man, young Emerson is the only white person to be open and honest with the narrator about the contents of Dr. Bledsoe's so-called "recommendation" letters. Though not perfect, young Emerson helps the narrator to see more of the truth of his life situation, and also gives the narrator his first break in Harlem by sending him to look for a job at Liberty Paints.
Ras's accent gives him a dimension of foreignness that is unique within this very American novel. We'd imagine it also helps with the whole black nationalist thing.
The narrator is hired as a speaker for a good reason. He is thoughtful and in touch with how to affect people with his words. Even though he is from the South, Ellison doesn't indicate that the narrator has much of an accent or whether he uses a Southern dialect. Yet one woman describes his voice as primitive at times, that she can hear "tom-toms" in it. The richness of his appeal as a speaker comes from his ability to tap into his listeners' deeper emotions, which the Brotherhood, with its emphasis on the intelligence of its audience, disapproves of greatly.
You probably noticed how odd the "Brother" talk is. Along with the discouragement of outside contact, the Brotherhood self-centers the speech of its participants, always adheres to ideology, and is always thinking of an abstract master plan.
"Poor southern uneducated speech" is used most prominently by Trueblood, highlighting his lack of education, but the narrator also uses it ironically in his scene with Sybil when he says, "I rapes real good when I'm drunk." His use of this sentence emphasizes the disconnect between Sybil's fantasy of a black brute and the reality of the narrator's education, breeding, and character.