OF VALUE.

127

change in the labour required to obtain the
salmon, and how much to a change in that required
 to obtain the deer.
In this and other passages it will be found,
that although Mr. Ricardo is professedly speaking
 of a commodity produced by invariable labour,
 in the character of a measure of value, he
is in reality, without being conscious of the difference,
 altogether occupied with the consideration
 of that commodity as capable of indicating
variations in the producing labour of other commodities*.
 Instead of a measure of value,

* The same remark will apply to economists in general.
Their real object in seeking for a measure of value (however
 little they may be aware of it) is to determine in which
commodities any changes of value have originated, and not
to ascertain the extent of these changes, which, as I have
repeatedly stated, are matters of record and evidence, and
a knowledge of which is in reality pre-supposed in any application
 of what they call a measure. It is not, therefore,
 a measure of value which they are in pursuit of, but
a commodity which would indicate the sources of variation.
Whether there is any one object which would do this better
than another, would at all events be a rational. and might
prove a useful inquiry.