In this paper I argue first that Marx's Critique of Political Economy employs “critique” in the Kantian meaning of the term—i.e., determining the domain of legitimate application of the categories involved and maintaining that outside these borders understanding is led into error and entangled in metaphysics.
According to Marx, his predecessors in political economy transgressed these boundaries of application, and therefore conceived of all different modes of production as being essentially similar to commodity production, and thus implied that commodity production and the bourgeois form of life corresponding to it are “natural” not historical and transitory. In Marx's conception there are no super-historical economic categories or laws.
I argue moreover that Marx's methodology of reconstructing the “development” of socioeconomic entities and categories from their “germ” or “cell” also serves his critical intention. Whereas social theorists of the time referred with organic metaphors to human collectives (“family,” “community,” etc.), Marx referred with such metaphors to economic entities only (“commodity,”“money,” etc.). The difference is crucial, since the first carries deterministic consequences for the development of society while the latter does not: Social form and historical development in Marx are contingent and not necessary, historical and not natural, transitory and not eternal.
I also stress that Marx's procedure of critique is internal. He uses only such assumptions, observations, and arguments as could in principle also be used by the scholars criticized. Nevertheless the outcome of the critique is not merely a new theory but an entirely different one — i.e., a historical conception of the discipline of political economy and of its laws.