Can there be anything new to say on this topic? I hope so: Gil Skillman [PEN-L:4342, 2 Mar 1995, 17.17.09.31] writes that "Andrew [Kliman] suggests that for Marx the notion that commodity exchange 'expresses something equal' is a *postulate*." What I wrote [PEN-L:4328, 1 Mar 1995, 11:00.33.69] was that "His demonstration goes from the postulated exchange of equivalents ..., to the existence of a common 'something,' not the converse." In other words, what is postulated is the equivalence, while what is derived is the existence of a common something which is none of the commodities themselves. It might seem self-evident to Gil or others that if two things are equal, they are equal by virtue of having a property in common which is different from the physical existence of either. But Marx took the pains to derive this, because it was not self-evident to Samuel Bailey, the author of the _Verbal Observations_, etc., and even the best of the Ricardians tended to confuse value with exchange- value, which enabled the Baileys, etc. to score some points against the concept of value. Thus it seems to me that there is a genuine derivation taking place, on the basis of a postulated equivalence. John Rosenthal [PEN-L:4350, 3 Mar 1995] has again performed a valuable service in clarifying the meaning of "gleich" as possibly indicating a qualitative "equivalence," which does help explain what in fact was being postulated. I also thought he put the point very nicely when he wrote that "Unless we assume that the ratios at which commodities exchange is entirely a function of idiosyncratic features of the actual exchanges which take place, then it is pretty obvious that their exchange-values ... are indeed comparable and hence that the 'common element' that enables this comparison must indeed exist." In his Notes on Adolph Wagner, Marx indicates that what he was doing in the first chapter was in fact analyzing a price list! (I have the translation by Terrell Carver, in Karl Marx, _Texts on Method_, 1975; Carver's intro. makes a point of this). Now I don't remember whether Marx was referring to to passage under discussion or the later derivation of the forms of value, but the point is the same. Let us take the following: 250 tins bootblacking .....................$500 1 qtr. wheat ..............................$500 4 bolts of silk ...........................$500 etc. This is essentially just the reverse of the series Marx presents: 1 qtr. wheat = x bootblacking, or = y silk, or = z gold, etc. Now notice two things. Firstwhat is at issue is not an actual act of exchange, but a series of *expressions* of equality. (This helps explain the term "exchange relation"--here we have a series of exchange relations, which do not imply any actual exchanges take place.) Second, Marx is beginning with a *datum*, a fact, something which obviously exists--if we use the correct numbers for x, y, and z, such a series will always exist, given this form of society, capitalism. The question is: do the 250 tins of bootpolish, the quarter of wheat, the 4 bolts of silk express something equal? If yes, is it $500? Ok, but doesn't this mean the $500 is equal to the 250 tins, the 1 quarter of wheat, etc? Now, this is circular reasoning, and the only way to break out of the cir- cularity to to recognize that they are all equal by virtue of having something else in common, different from all of them. If one reads the section of the Theories of Surplus-Value on Bailey, it becomes very clear that this is what Marx was driving at in the opening pages of Capital. One minor point. John wrote that "Bohm-Bawerk *accepts all this*", i.e., the existence of a common element. I don't think he actually did. He wrote that change of ownership involves inequality (otherwise they wouldn't trade), and thus questioned the notion that exchange is an exchange of equivalents. But he quickly moved on, because his main beef was with what he (mis)construed Marx as saying, that equal quantities of labor exchange. Andrew Kliman
