The questions raised by a number of commentators concerning the great differences between 21st-century capitalism and mid-19th century capitalism deserve extended answers, which I am not yet ready to attempt, but there is one tiny point I should like to clarify since it is, I think, one of the wittiest comments in Capital. It concerns the subject of transubstantiation.
In the Roman Catholic ritual of the mass the wafer and the wine are miraculously converted into the body and blood of Christ by God when the priest raises them and ask for a blessing. The taste of the wafer and the wine, their look and smell, do not change. In other words the accidents remain the same, to use the classical philosophical terminology, but the substance of the wafer and the wine are changed into the substance of the body and blood of Christ. Hence this ritual miracle is called transubstantiation. This is the central and most important miracle of Christianity and it is a miracle repeated every time that a priest anywhere in any church in the world celebrates a mass.
In the marketplace capitalists exchange commodities – linen for wheat, beef for iron, wool for copper. When two commodities, let us say a bushel of wheat and a ton of iron, exchange with one another the accidents of the commodities change – a capitalist who had iron before now has wheat and the look, the feel, the solidity, and all the other accidents of what he possesses have changed. But according to the classical political economists, at least in the simple case for which Ricardo’s labor theory of value works, the quantity of labor embodied in the two commodities is unchanged, for equals have exchanged for equals. This embodied labor, this abstract socially necessary labor as Marx would put it, is the substance of commodities, it is what the capitalist cares about in his effort to make a fair and equal exchange in the market.
The classical political economists believed that what takes place in the church is mysterious, magical, supernatural, inexplicable by ordinary reason, and they also believe that what takes place in the marketplace is ordinary, transparent, comprehensible, and utterly un-mysterious.
But, Marx says, what happens in the marketplace is merely the inversion of what happens in the church. In the church, the substance changes and the accidents remain the same whereas in the marketplace the substance remains the same and the accidents change. If what happens in the church is mysterious then so must be what happens in the marketplace. This is, in my personal opinion, a stunningly brilliant move by Marx to force his readers to recognize that capitalism requires a deep, penetrating, demystifying account.