Ellison uses Brother Jack, the leader of the Brotherhood, to point out the failure of abstract ideologies to address the real plight of African Americans and other victims of oppression. At first, Jack seems kind, compassionate, intelligent, and helpful, a real boon to the struggling narrator, to whom he gives money, a job, and—seemingly—a way to help his people fight against prejudice. But as the story progresses, it becomes clear that the narrator is just as invisible to Jack as he is to everyone else. Jack sees him not as a person but as a tool for the advancement of the Brotherhood’s goals. It eventually becomes clear to the narrator that Jack shares the same racial prejudices as the rest of white American society, and, when the Brotherhood’s focus changes, Jack abandons the Black community without regret.

The narrator’s discovery that Jack has a glass eye occurs as Jack enters into a fierce tirade on the aims of the Brotherhood. His literal blindness thus symbolizes how his unwavering commitment to the Brotherhood’s ideology has blinded him, metaphorically, to the plight of Black people. He tells the narrator, “We do not shape our policies to the mistaken and infantile notions of the man in the street. Our job is not to ask them what they think but to tell them!” Throughout the book, Jack explains the Brotherhood’s goals in terms of an abstract ideology. He tells the narrator in Chapter 14 that the group works “for a better world for all people” and that the organization is striving to remedy the effects of too many people being “dispossessed of their heritage.” He and the other brothers attempt to make the narrator’s own speeches more scientific, injecting them with abstractions and jargon in order to distance them from the hard realities that the narrator seeks to expose.

To many Black intellectuals in the 1930s, including Ellison, the Communist Party in particular seemed to offer the kind of salvation that Jack appears to embody—only to betray and discard the African-American cause as the party’s focus shifted in the early 1940s. Ellison’s treatment of the Brotherhood is largely a critique of the poor treatment that he believed the Black community had received from communism, and Jack, with his red hair, seems to symbolize this betrayal.