In so far as the right to the whole product of labour has been based upon the labour theory of value, it may be summarily dismissed from consideration. The value of products is neither created nor adequately measured by labour; it is determined by utility and scarcity. Labour does, indeed, affect value, inasmuch as it increases utility and diminishes scarcity, but it is not the only factor that influences these categories. Natural resources, the desires and the purchasing power of consumers determine value quite as fundamentally as does labour, and cause it to vary out of proportion to the labour expended upon a commodity. To-day there are probably not many adherents of the right-to-the-whole-product doctrine who attempt to base it upon any theory of value. The majority appeal to the simple and obvious fact that the labourers, together with the active directors of industry, are the only human beings who expend energy in the productive process. The only labour that the capitalist and the landowner perform in return for the interest and rent that they respectively receive, consists in choosing the particular goods in which their money is to be invested. As capitalist and landowner, they do not participate in the turning out of products. They are owners but not operators of the factors of production. In the sense, therefore, of active agents the labourers and the business men are the only producers. Whether land and capital should be called _productive_, whether the product should be regarded as _produced_ by land and capital as well as by labour and undertaking activity, is mostly a matter of terminology. Inasmuch as they are instrumental in bringing forth the product, land and capital may properly be designated as productive, but not in the same sense as labour and business energy. The former are passive factors and instrumental causes of the product, while the latter are active factors and original causes. Moreover, the former are non-rational entities, while the latter are attributes of human beings. As we have seen in former chapters, it is impossible to prove that mere ownership of a productive thing, such as a cow, a piece of land, or a machine, necessarily creates a right to either the concrete or the conventional product. The formula, "_res fructificat domino_," is not a self evident proposition. Nor are there any premises available from which the formula can be logically and necessarily deduced. On the other hand, we cannot prove conclusively that ownership of productive property does _not_ give a right to the product. Whence it follows that the owners of land and capital have at least a presumptive claim to take rent and interest from their possessions. Moreover, those owners of capital who would not have saved money without the hope of interest have a just claim thereto on account of their sacrifices in saving.