This is a comprehensive history of the postwar avant-garde. The author integrates such diverse moments in American culture as abstract expressionism, bebop jazz, gestalt therapy, Black Mountain College, Jungian psychology, beat poetry, experimental dance, Zen Buddhism, Alfred North Whitehead's cosmology, and the anti-nuclear movement. He aims to show how a variety of artistic movements actually had one unifying theme: spontaneous improvization. The author describes the intersection of Jackson Pollock's drip painting technique with the history of dance and bodily expression, and uncovers parallels between the beat fascination with Zen and bebop prosody. Through readings of works and explanations of their social, political and intellectual contexts, Belgrad reconstructs the mentality of this counterculture and describes how the aesthetics of spontaneity contradicted the dominant consumer society of the 1950's. Focusing on the works of key cultural figures such as Charles Olson and Jack Kerouac, the author aims to revise who and what are the most significant voices of the period.