ESTIMATING VALUE. 157 
dity in relation to which it has thus varied, or, 
at all events, the commodity should be clearly 
indicated by the tenour of the language em- 
ployed. Otherwise, two disputants in Political 
Economy may share the fate of the two 
knights, who fell sacrifices to their obstinacy in 
maintaining, the one that a shield was of gold, 
the other that it was of silver, both being 
equally correct in their assertions, and their 
difference arising, as a thousand differences 
arise, from the simple circumstance of having 
looked at opposite sides of the same object. 
The present subject may be further elucidated 
by citing a passage from Mr. Ricardo. « The 
labour of a million of men in manufactures,” 
says he, ¢ will always produce the same value, 
but will not always produce the same’ riches. 
By the invention of machinery, by improve- 
ments in skill, by a better division of labour, 
or by the discovery of new markets, where 
more advantageous exchanges may be made, a 
million of men may produce double or treble 
the amount of riches, of necessaries, conve-