Devout Catholic, converted Jew, homosexual, and a rumored ether addict, Max Jacob seems an unlikely representative of the various avant-garde movements with which he has been identified. Although a close friend of Pablo Picasso and Guillaume Apollinaire, as well as such younger writers as Michel Leiris, Jean Cocteau, and Edmond Jabès, whom he encouraged and inspired, Jacob has been accorded only a tangential status in the Orphist, Surrealist, and other postsymbolist movements of the period. His real but eccentric contributions to modernist poetics were eclipsed by those of his contemporaries who assumed the role of modern master with greater facility. Unlike such poets as Apollinaire and Blaise Cendrars, Jacob combined clownish dandyism with deep religious humility in a way that discomfited his avant-garde peers and impeded serious consideration of his achievements. The work itself proved difficult to categorize. His poetic experiments were diverse and far-reaching but...