PREFACE.

vii

The causes of value have been also too negligently
 passed over. Little inquiry has been
made into the nature of these causes, or their
mode of operation, and to this slightness of
examination may be attributed several important
 errors, manifested in attempts at undue
generalization, in perversions of language,
and in the rejection of circumstances which
have a real and permanent effect.

A singular confusion has also prevailed with
regard to the ideas of measuring and causing
value, and in the language employed to express
them. The perpetual shifting from one notion
to the other, the use of common terms for both
ideas, and the consequent ambiguity, vacillation,
 and perplexity, exhibit a remarkable
picture of the difficulty of thinking with close.
hess, as well as of the defects of language as
an instrument of reasoning.
The confusion and obscurity, which mark the