The reader who is new to Capital might well wonder why Marx chose to begin his study of the capitalist mode of production with a detailed account of commodity production – of the lowly commodity of all things? In a book entitled Capital, why not start with a definition of the concept of capital itself – something which in fact we do not get until nearly five hundred pages later (Capital, Vol. I, Part VII, Ch. 24) – or at the very least start with the concept of capital in its money form as Marx does in the Grundrisse, the notebook he wrote in 1857–8 in preparation for writing Capital itself ? What have commodities got to do with anything, we might ask, and why apparently are they quite so important to this question? In fact, the reason Marx begins Capital with a discussion of commodities is fairly clear: he wished to take seriously one of the most fundamental claims of vulgar and classical political economy; namely, the belief that, even when they are paid only a minimum or subsistence wage, labourers are in fact paid the full value of their labour-power when they exchange this as a commodity. Marx was forced to accept this claim because he wanted to be able to argue in his turn that capitalists too are paid the full value of their labour-power (as it were) when they have received back from their enterprise a sum equivalent in value to what they put into it, and nothing more than this. If it was fair to say that the labourer is paid the full value of their work when they are paid only a subsistence wage – the bare minimum required to live and reproduce themselves as labourers – then it must also be fair to say that the capitalist is only entitled to get back from the capitalist enterprise nothing more and nothing less than they have themselves put into this. In order to make this point, Marx was forced to accept (a) that labour-power was a commodity and (b) that, as such, it therefore must exchange at its full value.