The crucial importance of Karl Marx’s thought for his own time and for ours is beyond dispute, but the there have always been two considerable impediments to understanding: first, the supposed complexity with which Marx articulated his ideas; second, the accretions which commentators, disciples, and hagiographers have built into the original structure. Henri Lefebrve, who has held the chair in sociology at Strasbourg and since 1965 in Paris, has written an interpretative introduction which restores the clarity of outline and the vigor of the original. Lefebrvre also demonstrates by ample quotation that Marx, far from being the tortuous and intractable stylist we had imagined, is a masterful and witty writer.   But beyond this, the reader is presented with a thesis. Lefebvre argues that Marx was not a sociologist, not an economist, not yet an historian or a philosopher. On the other hand, one can find in his writings a sociology, a political economy, a theory of history, and significant intimations of a philosophy. The explanation of this apparent paradox lies in the fact that Marx was writing in a period prior to the compartmentalizing of science, when the nature of things could still be grasped as a whole. Thus, through Marx, we can obtain a coherent picture of reality as it was at the inception of the modern age. An understanding of Marx is necessary for an understanding of our time. This book is indispensible not only as a guide to Marx, but for its sight into contemporary problems.