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 be- 
tween the two ideas. 
Thus in the first section of his book he ac- 
cuses 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 es- 
timating food and necessaries * by the quantity 
of labour necssary for their production ;” con- 
trasting it with measuring them “by the quan- 
tity 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