wheat per year, and 100 men can produce, in one year, 120 quarters. Here
the price paid for labour is to the produce of that labour as 100 to
120, and profits are 20 per cent. Suppose now that, in another country,
wages are just double what they are in the country before supposed;
namely, two quarters of wheat per year, for each labourer. But suppose,
likewise, that the productive power of labour is double what it is in
the first country; that by the greater fertility of the soil, 100 men
can produce 240 quarters, instead of 120 as before. Here it is obvious,
that the real price paid for labour is twice as great in the one country
as in the other; but the produce being also twice as great, the ratio
between the price of labour and the produce of labour is still exactly
the same: an outlay of 200 quarters gives a return of 240 quarters, and
profits, as before, are 20 per cent.

Profits, then (meaning not gross profits, but the rate of profit),
depend (not upon the price of labour, tools, and materials--but) upon
the ratio between the price of labour, tools, and materials, and the
produce of them: upon the proportionate share of the produce of industry
which it is necessary to offer, in order to purchase that industry and
the means of setting it in motion.

* * * * *

We have hitherto spoken of tools, buildings, and materials, as
essentials of production, co-ordinate with labour, and equally
indispensable with it. This is true; but it is also true that tools,
buildings, and materials, are themselves the produce of labour; and that
the only cause (cases of monopoly excepted) of their having any value,
is the labour which is required for their production.