The expectation is well founded. Not a single conclusive argument can be brought forward to show that the productivity of capital directly and necessarily confers upon the capitalist a right to the interest-product. All the attempted arguments are reducible to two formulas: "res fructificat domino" ("a thing fructifies to its owner") and "the effect follows its cause." The first of these was originally a legal rather than an ethical maxim; a rule by which the title was determined in the civil law, not a principle by which the right was determined in morals. The second is an irrelevant platitude. As a juristic principle, neither is self evident. Why should the owner of a piece of capital, be it a house, a machine, or a share of railway stock, have a right to its product, when he has expended neither time, labour, money, nor inconvenience of any kind? To answer, "because the thing which produced the product belongs to him," is merely to beg the question. To answer, "because the effect follows the cause," is to make a statement which has nothing to do with the question. What we want to know is why the ownership of a productive thing gives a right to the product; why this particular effect should follow its cause in this particular way. To answer by repeating under the guise of sententious formulas the thesis to be proved, is scarcely satisfactory or convincing. To answer that if the capitalist were not given interest industry and thrift would decrease and human welfare suffer, is to abandon the intrinsic argument entirely. It brings in the extrinsic consideration of social consequences. _The Claims of Service_