This dissertation remaps the intellectual terrain of Abstract Expressionism, uncovering the deeply communal nature of the artists' aesthetic projects and shifting the narrative away from the usual biographical and psychoanalytic models. Drawing on extensive archival research, I argue that the early years of The Club, from 1949 to 1955, are central to understanding Abstract Expressionism. Not only does the evidence of the artists' weekly discussions suggest intellectual sources that have never before been associated with Abstract Expressionism (vitalism, Martin Heidegger's existentialism, Paul Goodman's Gestalt therapy, and Zen), but it also indicates that this social community embodied anarchist mutual aid that avoided the ideological Cold War rhetoric that pitted individualism against totalitarian collectivism. Vitalism's connectedness, Heidegger's Being-with, Gestalt therapy's organism-environment field, and Zen's awareness and interrelatedness addressed the fundamental issue of the individual's relationship with the collective, striking a new key that was neither Communist nor Capitalist. Using these discursive frames, I reread Harold Rosenberg's articulation of Action Painting and offer a new interpretation of the artists'"signature styles" as a community of difference rather than as emblematic of sovereign individuality. By looking at the artists' material processes and their compositional strategies, I recover on the surfaces of their canvases the communitarian impulses that also directed their intellectual discussions and their everyday lives. While Abstract Expressionism has come to signify heroic individuality and Cold War patriarchy, I want to suggest that it signifies the very obverse--radical community that recognized separate-togetherness. This rereading puts Abstract Expressionism squarely within the reformulation of Leftist politics that began after World War II and came to fruition in the New Left and the"new sensibility" of the 1960s.