It is sometimes asserted that the capitalist has as good a right to interest as the farmer has to the offspring of his animals. Both are the products of the owner's property. In two respects, however, the comparison is inadequate and misleading. Since the owner of a female animal contributes labour or money or both toward her care during the period of gestation, his claim to the offspring is based in part upon these grounds, and only in part upon the title of interest. In the second place, the offspring is the definite and easily distinguishable product of its parent. But the sixty dollars derived as interest from the ownership of ten shares of railway stock, cannot be identified as the exact product of one thousand dollars of railway property. No man can tell whether this amount of capital has contributed more or less than sixty dollars of value to the joint product, i.e., railway services. The same is true of any other share or piece of concrete capital. All that we know is that the interest, be it five, six, seven, or some other per cent., describes the share of the product which goes to the owner of capital in the present conditions of industry. It is the conventional not the actual and physical product of capital. Another faulty analogy is that drawn between the productivity of capital and the productivity of labour. Following the terminology of the economists, most persons think of land, labour, and capital as productive in the same sense. Hence the productivity of capital is easily assumed to have the same moral value as the productive action of human beings; and the right of the capitalist to a part of the product is put on the same moral basis as the right of the labourer. Yet the differences between the two kinds of productivity, and between the two moral claims to the product are more important than their resemblances. In the first place, there is an essential physical difference. As an instrument of production, labour is active, capital is passive. As regards its worth or dignity, labour is the expenditure of human energy, the output of a _person_, while capital is a material thing, standing apart from a personality, and possessing no human quality or human worth. These significant intrinsic or physical differences forbid any immediate inference that the moral claims of the owners of capital and labour are equally valid. We should logically expect to find that their moral claims are unequal.