The publication of my paper, 'Abstract labour: Against its nature and on its time' (2010), has provoked some debate. Abstract is indeed a critical category of capitalist wealth. For Kicillof and Starosta (2011), it denotes some generic materiality of beyond class relations, which they conceive of as expenditure of human energy, a purely abstract materiality that in capitalism takes the form of value. Carchedi (2011) sees it as a social-physiological category that has a specific class content. I argued that abstract is a purely social form of the capitalistically constituted relations of production. It is, I argued, the of socially necessary time. Value is a social category. It feeds on labour-time--socially necessary time. (1) The social wealth of our society is not a matter of a concrete producing use-values--things for use, to satisfy human needs and wants. It rests on something altogether different, something seemingly supersensible that does not contain an atom of use value, and cannot be touched, smelled, or seen. It rests, says Marx, on abstract labour. What does it mean to abstractly? The idea of as an abstract activity belongs conventionally to theological thought. I am clear in my own mind that abstract is not a physiological matter: the critique of political economy is a critical social theory of the capitalist constitution of social wealth, it is not a socio-physiological treatise about the expenditure of human energy in the abstract. I am also clear in my own mind that abstract is a material category, as opposed to a theological idea or natural-social occurrence that, akin to Smith's natural human propensity to barter, acquires fundamental social existence in capitalist society. Carchedi (2011) and Kicillof and Starosta (2011) offer robust reassertions of the (socio-)physiological definition of abstract labour, and argue that Marx was unambiguous on this matter. If this really were so, then that would be bad for Marx. At its best, historical materialism is a critique of things understood dogmatically. The circumstance that muscles burn sugar does not explain capitalist social relations, nor is this physiological fact and biological insight in any way helpful in deciphering the materiality of capitalist wealth. Turning to Carchedi, I argued in a footnote (2010: 274, fn. 18) that his account provides a 'robust assertion of the physiological definition of abstract that leads him [Carchedi] to argue that calories are the measure of value'. The remainder of the footnote gives credit where credit is due: 'For any embodied labour theory of value, this view makes good--Ricardian--sense'. His objection is threefold: he declares, first, that he conceives of abstract as both a physiological and a social category; and that, second, his reference to calories is merely an example of what he conceives of as the observable expenditure of abstract labour. The purpose of the example is to show the materiality of abstract before exchange. He conceives of the materiality of abstract as a 'purely abstract activity, a purely mechanical activity, activity pure and simple'. The third objection is this: he rejects as unfounded the praise afforded to him. In his view, it is wrong to say that 'abstract and thus value is only social', posits that Marx did not break with Ricardo on this point, and that therefore 'charges of Ricardianism will not do'. I have no charge to make. Carchedi argues with revealing clarity. Like Kicillof and Starosta, Carchedi asserts the materiality of abstract as expenditure of corporeal human energy as the holy grail of value theory. They seem agreed on the idea that the spheres of exchange and circulation are lacking in materiality and that, as it were, exchange merely circulates an already existing value-materiality, rendering individual concrete labours aliquot manifestations of human energy in the abstract. …