As a contribution to critical social theory, this book reconsiders Marx’s critique of political economy through the concept of labour as “not-capital”. Engaging with thinkers who have dealt with Marx’s concepts of “not-capital” and “not-value”, Tetler examines whether and how these concepts can contribute significantly towards a renewal of the critique of political economy beyond the limits of traditional Marxism. In doing so he provides the first in depth interrogation of these concepts, both within Marx’s work itself and within and across the various intellectuals who have put them to use in their attempts to address the faults of traditional Marxism. He argues that the theory of value that sits at the heart of Marx’s critique of political economy requires a negative conception of labour. In helping establish this, the notions of labour as not-capital/value are shown to have formidable ramifications concerning the crisis-ridden nature of capitalist social relations and the struggles operative within and against them.