196 ON THE CAUSES
extraordinary profit which is obtained by the
possession of an instrument of production, pro-
tected up to a certain point from competition.
If the owner of this instrument, instead of
using it himself, lets it out to another, he re-
ceives from him this surplus of profit under the
denomination of rent. In this view of the
subject, the extraordinary profit might exist, al-
though the land in cultivation were all of the
same quality ; nay, must exist before inferior
land was cultivated ; for it could be only in
consequence of extraordinary gains obtained
by the monopolizers of the best land, that ca-
pital and labour would be expended on soils of
a subordinate order. Rent, therefore, might ex-
ist, while all the land nnder cultivation was of
equal fertility. Perhaps it might not exist
under these circumstances during any long
period, but its existence at all would prove
that it was the effect of monopoly, an extra-
ordinary profit, and not the consequence of the
cultivation of inferior soils.

The extraordinary profit out of which rent