Law No. 4. The industrial state has an incomparably greater population capacity than the agricultural state {107}. Law No. 5. In the economy nothing takes place without a material interest {126}. In doing this we shall not consider those points which Herr D hring has merely copied from his predecessor Carey; we are not concerned with Carey, nor with defending Ricardo's views on rent of land against Carey s distortions and stupidities. We are only concerned with Herr D hring, and he defines rent as The case of self-management, as Herr D hring calls it or rather, the management of farms by bailiffs for the landowner s account, as happens most frequently in Germany does not alter the matter. If the landowner also provides the capital and has the farm run for his own account, he pockets the profit on capital in addition to the rent, as is self-understood and cannot be otherwise on the basis of the existing mode of production. And if Herr D hring asserts that up to now no one has found it necessary to conceive the rent (he should say revenue) resulting from the owner's own management as divided into parts, this is simply untrue, and at best only proves his own ignorance once again. For example: He eventually escapes from his quandary by an audacious trick: According to Herr D hring, therefore, the only difference between rent of land and earnings of capital is that the former is obtained in agriculture and the latter in industry or commerce. And it was of necessity that Herr D hring arrived at such an uncritical and confused view of the matter. We saw that his starting-point was the really historical conception , that domination over the land could be based only on domination over man. As soon, therefore, as land is cultivated by means of any form of subjugated labour, a surplus for the landlord arises, and this surplus is the rent, just as in industry the surplus-labour product beyond what the labourer earns is the profit on capital.
1877: Anti-Duhring - Natural Laws of the Economy