The “theoretical values,” so-called above, are those which would be in proportion to labor costs. The law of labor cost declares that the value of any given commodity is determined by its cost in labor. In admitting that in fact actual particular values do not follow this law, Marx has abandoned the law. (For a consideration of the erroneous claim that the average rate of surplus-value determines the average rate of profits, the reader may refer to Böhm-Bawerk’s essay.) The point desired to be made here, is that Ricardo’s difficulty of “fixed and circulating” capital is the same as that in the Marxian theory. Ricardo stated that variations in the proportions in which fixed and circulating capitals are combined in different industries introduces a second cause of change in the relative value of a commodity. The first cause is change in the quantity of labor required to produce a commodity; the second is a change in the general rate of wages. In the chapter in this history devoted to Ricardo, it has been argued at length[91] that what Ricardo said was only a round-about explanation of the fact that the values required by the labor theory are not the same as actual values. McCulloch, following Ricardo, discusses the same problem in the same way, and concludes that changes in the rate of wages will cause variations of values aside from the influence of pure labor cost. But he adds to what Ricardo has said, attempting a justification of the pure labor-cost theory on the grounds that it regulates average value. I trust what has been said will make it clear that McCulloch’s defense is identical in essence with that of Marx, though different in form. McCulloch wrote as follows, in 1849: “It should also be observed, that though fluctuations in the rate of wages occasion some variation in the exchangeable value of _particular_ commodities, they neither add to nor take from the _total value_ of the entire mass of commodities. If they increase the value of those produced by the least durable capitals, they equally diminish the value of those produced by the more durable capitals. Their aggregate value continues, therefore, always the same. And though it may not be strictly true of a particular commodity, that its exchange value is directly as its cost, or as the quantity of labour required to produce it and bring it to market, it is most true to affirm this of the _mass of commodities taken together_.”[92] McCulloch also expressed the same thought twenty-one years earlier, in 1828. Though a change of the rate of wages may cause a particular commodity to vary from its “real value,” “the exchangeable value of some other commodity must vary to the same extent in a contrary direction.”[93]