120

ON MEASURES

of the case have any commodity of invariable
value, by which to ascertain the fluctuations of
all other things, unless all commodities were
of invariable value, in which case there would
be no fluctuations to ascertain.
We have also seen in the present chapter,
that the demand for invariablenes of value in
any commodity to be used as a measure, is
founded altogether on a false analogy; that
Auctuations in value are not ascertained by any
measure, but by historical evidence; that a
measure of value can signify nothing but a
medium of comparison for contemporary commodities
 ; and that we have as good a measure
in this sense, not only as it is possible to have,
but as it is possible to conceive.
Besides these errors, there is to be discovered
 in Mr. Ricardo’s views, as to the uses of
a measure of value, a singular confusion of
thought, which I shall here endeavour to explain.


The soecific error of Mr. Ricardo on the subject
 of invariable value consists, as before
explained, in supposing, that il’ the causes of