I have to agree with the implications of both Allin's and Costas'
replies to my post. Marx does tie himself to commodity money
in Capital I, and it does cause problems for his theory of
money, which as Allin points out are: the question of what does
the value of money represent--the value of gold or a symbol of value
in general?; and the role of fiat money, which in this commodity
money sense of Marx's, ends up not being a "symbol of value". And
as Costas points out that begs the question of what fiat money
represents.
What I was pointing to in my post is that there is a different
concept of money floating around, undeveloped, in Marx's writings,
one that (in effect) begins with fiat money, rather than
commodity money, because it focuses on what money does (its function)
, and not on what is money (its physical manifestation, as gold or
pieces of paper). This concept leads to a much more sophisticated
analysis of money than does the commodity money concept, which
inevitably leads to a variant of the Quantity Theory. But I
would not argue that it was Marx's dominant manner of analysing
money--that title, unfortunately, definitely belongs to the
commodity money analysis of Volume I.
Cheers,
Steve Keen