216 ON THE CAUSES 
whatever in the fixed capital or the quantity 
of labour, there should happen to be a rise in 
the value of labour; according to Mr. Ricardos 
own showing, a and B would be instantly al- 
tered in their relation to each other; that is, 
they would become unequal in value. At the 
former period being equal in value, they must, 
according to the doctrine under consideration, 
have been the products directly or indirectly of 
equal quantities of labour; but if at the latter 
period their values were taken as repre- 
sentative of the relative quantity of labour ex- 
pended on each, the result obtained would be, 
that they were the products of unequal quantities 
of labour. The doctrine, therefore, that the 
values of commodities are representative of the 
respective quantities of labour required for 
their production, which is a direct corollary 
from the proposition that commodities are to 
each other in value as is their producing labour 
in quantity, cannot possibly be true. 
This again, it may be said, is allowed by 
Mr. Ricardo and his followers: but if they