Sebastiano Timpanaro (1923-2000) was one of the most original leftist thinkers of the 20th century. His thought spans a unique range of subjects, from materialism to classical philology, from the Enlightenment to Freud, from science to socialism, from the history of linguistics to 19th century Italian literature. Timpanaro confronted this manifold material with addictive clarity and incisive honesty. This book is the first serious attempt in any language to introduce Timpanaro's thought in its entirety. Drawing on original archival research, Geue shows the astonishing breadth of Timpanaro's intellect and his eccentric dual profile as a Marxist and technical philologist. From this emerges not only a compelling portrait of a neglected radical thinker, but also a rallying call for the Left to revive its commitment to scientific truth and rigorous detail.