This book is the first to explore in detail the encounter between Albert Flocon and Gaston Bachelard in postwar Paris. Bachelard was a philosopher and historian of science who was also involved in literary studies and poetics. Flocon was a student of the Bauhaus in Dessau, Germany, who specialized in copper engraving. Both deeply ingrained in the surrealist avant-garde movements, each acted at the frontiers of their respective métiers in exploring uncharted territory. Bachelard experienced the sciences of his time as constantly undergoing radical changes, and he wanted to create a historical epistemology that would live up to this experience. He saw the elementary gesture of the copper engraver—the hand of the engraver—as meeting the challenge of resistant and resilient matter in an exemplary fashion. Flocon was fascinated by Bachelard's unconventional approach to the sciences and his poetics. Together, their relationship interrogated and celebrated the interplay of hand and matter as it occurs in poetic writing, in the art of engraving, and in scientific experimentation. In the form of a double biography, Hans-Jörg Rheinberger succeeds in writing a lucid intellectual history and at the same time presents a fascinating illustrated reading of Flocon's copper engravings.