In the West today, Marxism has become a major intellectual language. But it is a language made up of many dialects, whose common root is not always easily discernible. This divergence and diversity has been occasioned both by specific historical conditions and by different utilisations of Marxism. Traditionally, and possibly also popularly, it has been seen primarily as an adjunct, guide and stimulant to political action. However, at least since the contributions of the Frankfurt School in the 1920s, it has been used with efficacy as an academic approach, an independent method whose direct connection with immediate political activity has been tangential or unclear. In post-war Western Europe, as Perry Anderson has shown (1976; and see also 1983), Marxism has been heard much more loudly in academia than in political debating chambers, more in the lecture room than on the factory floor, and the most interesting developments of Marxist thought have occurred almost exclusively in this intellectual forum. The historical and social reasons for the use of Marxist categories as epistemological tools rather than as political weapons, a use which negates the well-known Marxist insistence on the necessary relationship between theory and practice, are complex and beyond the scope of our brief introduction — Anderson traces some of these causes with great clarity.