Andrew writes, in the midst of a response to Paul: [.....]
> Just as in Ch. 5 of Vol. I, Marx is saying profit doesn't arise from
> unequal exchange. It doesn't matter whether we're talking about exchange
> at prices differing from values or from prices differing from average
> prices--the point is the same in either case, as Marx makes clear at the
> end of Ch. 5. (Gil: please note that I am providing an interpretation
> of Marx here and that the accuracy of that interpretation does NOT
> require that I prove the non-tautological nature of the claim, much less
> its validity.)
Fine by me, Andrew. Marx certainly asserts that surplus value cannot
arise from price-value disparities in exchange--**taken alone**. For
that matter it can't arise from price-value equivalence in exchange,
taken alone, either. This follows immediately from his definition of
surplus value (which requires the creation of new value, the latter defined
as socially necessary labor time expended in production) since exchange isn't
production. Whether you want to call this a strict tautology or not
is a matter of semantics.
The problem is Marx's inference, in the very last paragraph of Ch. 5,
as augmented by the last footnote, that capitalist exploitation must
be explained on the basis of the condition that all commodities
exchange at their respective values. This quite obviously does not
follow from the arguments given in the chapter. For example, these
arguments do not rule out the possibility that surplus value requires
that "something must take place in the background which is not
visible in the circulation itself",plus price-value *disparities*.
Indeed, this was certainly the case with respect to cases of
capitalist exploitation which preceded the capitalist mode of
production-- e.g. proto-industrial merchant's capital--as Marx
repeatedly affirms in his unpublished and published writing
stretching from 1857 to 1867.
Gil