Marxism's chief failing is its substitution of a labour theory of value for the struggles of the labour movement. Consequently, Marxism rests on transhistorical categories that are vulnerable to his own critique of political economy. Jurgen Habermas and Axel Honneth seek to correct this by placing critical theory on a normative foundation. Unfortunately, they restrict this to the cultural sphere. By extending their notion of intersubjectivity to the economic system it can be viewed as an inactive form of morality which social movements influence in the course of their struggles.