What remains valid of the first chapter of Marx’s Capital

What of the first chapter of Marx’s Capital remains valid if one adopts Sraffian price theory? More than one might think, given that the thesis that labour is the substance of value must be abandoned; the two main new clarifications the chapter intended to contribute, namely the analysis of fetishism (with that of the forms of value which is its necessary premise), and the concrete labour/abstract labour distinction, remain valid. The reason why the first pages of the chapter are unclear and aprioristic is traced to Marx’s decision to postpone to Volume III the ‘compensation-of-deviations’ argument with its premise that commodities do not exchange in proportion to embodied labour, a decision which obliges him to assume in this chapter a strict labour theory of value without explanation of why it holds. Böhm-Bawerk’s interpretation of the ‘only-one-property-remains’ argument is criticised. Marx’s persuasion that when things are quantitatively comparable relative to a common quality there must be a common ‘substance’ in them determining that comparability is discussed. The need to ‘reduce’ labour to homogeneity clarifies the meaning of abstract labour but contradicts Marx’s insistence on the notions of ‘human labour in general’ and ‘equality and equivalence of all kinds of labour’.