A small but important correction is needed to my response
to Allin, which seems to have slipped through the late-night
censor's pen:
The paragraph which begins
"We require a category of value in order to make the statement
that has just been made. But this category of value is *not*
derived from exchange"
This should read
"We require a category of value in order to make the statement
that has just been made. But though this category of value is
derived from exchange, its magnitude is *not* derived from
exchange."
Apologies for any confusion this may have caused.
Alan