28 
ON THE NATURE 
work he says, ‘I cannot agree with M. Say in 
estimating the value of a commodity by the 
abundance of other commodities, for which it 
will exchange *®.” In accordance with the de- 
finition, this means that he cannot agree with 
M. Say in estimating the power of a commo- 
dity to purchase other commodities, by the 
quantity of the latter, which it will purchase. 
But if the power of a commodity to purchase be 
not measured by the quantity purchased, what 
other mode of estimation can be found? It is 
no great degree of boldness to challenge the 
whole body of economists to produce a differ- 
ent meaning of the word power, or a different 
measure of its degrees. 
One of the most accomplished of Mr. Ri- 
cardo’s disciples, the author of the Templars’ 
Dialogues on Political Economy, whose writings 
relative quantity of labour which is necessary for its pro- 
duction, and not on the greater or less compensation which 
is paid for that labour.” See title of Section i, Chap. 1. 
* Page 333, third edition.