A MEASURE AND A CAUSE OF VALUE. 173

logues asserting, that Mr. Ricardo did not
propose his principle of value (namely, the
quantity of labour) as the measure of value.
The fact is, that he sometimes speaks of it as
the cause, and sometimes as the measure, in
such a way as proves that he had not attained
to any distinct conception of the difference between
 the two ideas.
Thus in the first section of his book he accuses
 Adam Smith of erecting the labour, which
a commodity will command, into a standard
measure, instead of the labour bestowed on its
production, the latter of which he asserts to
be, ¢ under many circumstances, an invariable
standard, indicating correctly the variations
of other things*.” Farther on he speaks of estimating
 food and necessaries * by the quantity
of labour necssary for their production ;” contrasting
 it with measuring them “by the quantity
 of labour for which they will exchange? .”
In the second section, after speaking of la-*

 Principles of Political Economy and Taxation, Pp. 5,
3d edition.
+ Ibid, p. 7. The Italics are Mr. Ricardos