nsable conditions. First, there can be no rent if labour does not produce more than the amount which is just necessary to the labourers to secure the continuance of their labour, for it is impossible that without such a surplus any one, without himself labouring, can regularly receive an income. Secondly, there could be no rent if arrangements did not exist which deprive the labourers of this surplus, either wholly or in part, and give it to others who do not themselves labour, for in the nature of things the labourers themselves are always the first to come into possession of their product. That labour yields such a surplus rests on economic grounds that increase the productivity of labour. That this surplus is entirely or in part withdrawn from the labourers and given to others rests on grounds of positive law; and as law has always united itself with force it only effects this withdrawal by continual compulsion.
"The form which this compulsion originally took was slavery, the origin of which is contemporaneous with that of agriculture and landed property. The labourers who produced such a surplus in their labour-product were slaves, and the master to whom the labourers belonged, and to whom consequently the product itself also belonged, gave the slaves only so much as was necessary for the continuance of their labour, and kept the remainder or surplus to himself. If all the land, and at the same time all the capital of a country, have passed into private property, then landed property and property in capital exert a similar compulsion even over freed or free labourers. For, first, the result will be the same as in slavery, that the product will not belong to the labourers, but to the masters of land and capital; and secondly, the labourers who possess nothing, in face of the masters possessing land and capital, will be glad to receive a part only of the product of their own labour with which to support themselves in life; that is to say, again, to enable them to continue their labour. Thus, although the contract of labourer and employer has taken the place of slavery, the contract is only formally and not actually free, and Hunger makes a good substitute for the whip. What was formerly called food is now called wage."*26
Thus, then, all rent is an exploitation,*27 or, as Rodbertus sometimes calls it still more forcibly, a robbery of the product of other people's labour.*28 This character applies to all kinds of rent equally; to land-rent as well as to profit on capital, and to the emoluments of hire and loan interest derived from them. Hire and interest are as legitimate in connection with the undertakers as they are illegitimate in connection with the labourers, at whose cost, in the last resort, they are paid.*29
The amount of rent increases with the productivity of labour; for under the system of free competition the labourer receives, universally and constantly, only the amount necessary for his maintenance—that is, a definite quantum of the product. Thus the greater the productivity of labour the less will be the proportion of the total value of the product claimed by this quantum, and the greater will be the proportion of the product and of the value remaining over to the proprietor as his share, as rent.*30
Although, according to what has been already said, all rent forms a homogeneous mass having one common origin in practical economic life, it is divided into two branches, land-rent and profit on capital. Rodbertus then explains the reason and the laws of this division in a most peculiar way. He starts from the theoretical assumption, which he carries through all his investigation, that the exchange value of all products is equal to their labour-costs; in other words, that all products exchange with each other in proportion to the labour they have cost.*31 Rodbertus indeed is aware that this assumption does not exactly correspond with reality. Still he believes that the deviations amount to nothing more than that "the actual exchange value falls sometimes on the one side, sometimes on the other," in which cas