102

ON MEASURES

measure of value can mean nothing but a commodity
 employed as a medium of comparison,
and that so far from its being impossible to
have any thing perfectly capable of performing
this function, we are in the daily use of one
possessing all the perfection which it is possible
 to conceive. Inregard to measuring or comparing
 value, there is no operation which can
be intelligibly described or consistently imagined,
 but may be performed by the media of
which we are in possession.
It is astonishing, indeed, to find how slight
are the analogies with which economists have
contented themselves on this subject, and which
have served to preclude any close investigation
of processes essentially different, although confounded
 under the same appellation. One of
the most striking instances of this carelessness
of examination is the notion of its being necessary,
 that a commodity should possess invariable
 value, in order to form a perfect measure
 of value; a notion which has passed unquestioned
 from one writer to another, and been