If a ram and a sheep are capital which yields just interest, because their wool and their progeny are increments due to nature, and if a ram and a sheep are exchangeable for some kind of machine, the possession of the one must be placed on a par with the possession of the other.

The machine must be treated, though it is not so in strictness, as if it were prolific in the same sense as the beasts are; and a part of what it is used to produce must be paid by the user to the owner of it.
Now, both these arguments--that which deals with the fact of natural increase, and that which deals with the assimilation of all such possessions as are interchangeable--are in principle sound.

The first, indeed, touches the very root of the whole matter; but the first is exaggerated in his statement of it, and unduly limited in his application, and the second is wholly unnecessary for proving what he desires to prove.

The first is exaggerated in his statement of it because, as a matter of fact, the kind of capital whose interest is described by him as the gift of nature is not the major, it is only a minor part of the capital yielding interest under the conditions which obtain to-day.

A part far larger is capital in the form of machinery; and if the distinction which George draws between the two is a true one, the case of the flocks and herds should be assimilated to that of the machines, not the case of the machines to that of the flocks and herds.
Interest should be denied to both kinds of capital because machines are not naturally prolific, instead of being conceded to both because flocks and herds are so.