Rent can develop as money-rent only on the basis of commodity production, in
 particular capitalist production, and it develops to the same extent that
 agricultural production becomes commodity production, that is, to the same
 extent that non-agricultural production develops independently of agricultural
 production, for to that degree the agricultural product becomes commodity,
 exchange-value, and value. In so far as commodity-production and thus the
 production of value develops with capitalist production so does the production
 of surplus-value and surplus product. But in the same proportion as the latter
 develops, landed property acquires the capacity of capturing an ever-increasing
 portion of this surplus-value by means of its land monopoly and thereby, of
 raising the value of its rent and the price of the land itself. The capitalist
 still performs an active function in the development of this surplus-value and
 surplus-product. But the landowner need only appropriate the growing share in
 the surplus-product and the surplus-value, without having contributed anything
 to this growth. This is the characteristic peculiarity of his position, and not
 the fact that the value of the products of the land, and thus of the land
 itself, increases to the degree that the market for them expands, the demand
 grows and with it the world of commodities which confronts the products of the
 land — in other words, the mass of non-agricultural commodity producers
 and non-agricultural commodity-production. But since this takes place without
 any action on his part, it appears to him as something unique that the mass of
 value, the mass of surplus-value, and the transformation of a portion of
 surplus value into ground-rent should depend upon the social production
 process, on the development of commodity-production in general. For this
 reason, Dove, for instance, tries to evolve rent from this. He says that rent
 does not depend upon the mass of the agricultural product, but upon its value,
 [P. Dove, The Elements of Political Science, Edinburgh, 1854, p.279.
 — Ed.] however, this depends upon the mass and productivity of
 the non-agricultural population. But it is also true of every other product
 that it can only develop as a commodity partly as the mass and partly as the
 variety of other commodities which form equivalents for its increase. This has
 already been demonstrated in connection with the general presentation of value.
 [English edition: Vol. I, p. 88. — Ed.] On the one hand, the
 exchangeability of a product in general depends on the multiplicity of
 commodities existing in addition to it. On the other hand, on it depends in
 particular the quantity in which this product can be produced as a commodity.