In the early 20th century, Marxist theory was enriched and rejuvenated by adopting the concept of reification, introduced by the Hungarian theorist Georg Lukacs to identify and denounce the transformation of historical processes into ahistorical entities, human actions into things that seemed part of an immutable "second nature." For a variety of reasons, both theoretical and practical, the hopes placed in de-reification as a tool of revolutionary emancipation proved vain. In these original and imaginative essays, delivered as the Tanner Lectures at the University of California, Berkeley in...