Karl Marx reminds us that materialism is not empiricism. In fact in his hands materialism may not be materialism. Which is to say, Marxism's defining characteristic is that it is mystic. Of course this assertion flies in the face of its most fundamental epistemological principle. Namely, that in turning Hegel the right way up the idealist mumbo jumbo of the Hegelian dialectic took on materialist form. As such it was accessible to everyone, an analytical tool that explained the contingent nature of all cultural and intellectual phenomena. Furthermore, it laid out a program of revolution whereby the world itself would be upturned. The upshot of all this is the orthodox axiom that in adding materialism to the mix Marx had rescued Hegel. He had made him, in every sense, sensible. As Brecht said in his poem “In Praise of Communism,” to understand all of this is “easy.”

The trouble is, once we have accepted that history is driven by the appropriation of the means of production and the development of class society, Marx's materialism doesn't go much further in ontological terms. In modern society, moreover, the mechanism of change—class warfare—rests on a formula that in a highly naive manner calculates the exact sum the capitalist has stolen from the worker. This is the so-called surplus value of labor, and it becomes the Boyle's law of dialectical materialism in the capitalist era, underpinning the elaborate macrostructure that follows: the evolution of the proletariat into a universal class that attains an unprecedented degree of historical understanding, the mechanisms by which the bourgeoisie produces its own gravediggers, and so on. Therefore it has to be an unqualified and unassailable expression of market value, no matter how unstable the market is. Ironically, Marx's positivism forces him to pay at least as much homage to the rationality and authority of the capitalist market as any disciple of Fri edrich Hayek.