> It is wrong to rule out empirical test in judging the validity
> of the labour theory of value. It is in principle possible for
> the common substance behind value to be something other than
> labour. One could hypothesise that some other input that
> entered directly or indirectly into the production of all others
> was the common substance. Energy would be an obvious candidate,
> or more abstractly negative entropy.
For what it's worth, I didn't "rule out" any such thing. I only said
that tests of the labor theory of value would not yield implications
one way or the other about the notion that exchange "expresses
something equal."
Gil Skillman