36

ON THE VALUE

by the same labour, they would fall to half
their former value, the correctness of which
will be hereafter examined in the chapter on
the methods of estimating value.
The error, however, which it belongs to the
purpose of the present chapter to point out, is
a departure from his own definition of value.
Instead of regarding labour as rising or falling
according as it commands a greater or smaller
quantity of the commodities exchanged for it,
which is a direct corollary from the definition
of value as the power of purchasing or commanding
 other objects in exchange, he represents
 it as rising or falling only when a larger
or smaller proportion of the commodity produced
 goes to the labourer. This variation in
the proportion of the product is undoubtedly
one source of variation in the value of labour,
but it is not the sole source. As value, when
applied to labour, denotes its relation to other
things, that value must vary, not only from
causes which affect labour, but from causes
which affect the commodities received in exchange
 for it. To take Mr. Ricardos own