Published in 1933, at a time of widespread unemployment and bank failures, this book by the young Sidney Hook received great critical acclaim and established his reputation as a brilliant expositor of ideas. By revolutionary interpretation Hook meant quite literally that Marx's main objective was to stimulate revolutionary opposition to class society. Hook later abandoned the revolutionary views expressed in this volume, but he never abandoned his warm positive views of Marx as a thinker and a fighter for freedom. He eventually concluded that 20th century history had proved both him and Marx wrong about the necessity of revolutionary means to achieve their mutual social goals. But, says his son Ernest B. Hook in an introduction, this concession of error he did not see . . . as an admission of intellectual weakness, but the natural position of a reasonable person when, in the light of observation and experience, he concludes he has erred. This expanded edition makes readily available for scholars an influential work long out of print and provides critical insight into the intellectual development of one of the 20th-century's great thinkers.