PREFACE. 
It is remarked by another author, that * he 
who is fully master of the subject of Value is 
already a good political economist.” ¢ Even 
for its own sake,” he adds, * the subject is a 
matter of curious speculation: but in relation 
to Political Economy it is all in all: for most 
of the errors (and, what is much worse than 
errors, most of the perplexity) prevailing in 
this science take their rise from this source*.” 
Although much has been written and many 
efforts have been made fo overcome the ob- 
stacles, which present themselves in this part of 
economical science, it may be affirmed with 
little risk of contradiction, that the success 
has not been in proportion to the labour be- 
stowed. There appears to have been too little 
circumspection at the outset. The ground- 
work of the subject has not been examined 
* The Templars’ Dialogues on Political Economy, 
in the London Magazine for April, 1824, pages 341 
and 342.