§ 11. The truth here insisted on, that an exact quantitative relation exists between the amount of stock and plant, severally and collectively, required at the different points A, B, C, D, E, and that the amount economically serviceable at each point is determined by the quantity of current consumption, would seem self-evident. But though this has never been explicitly denied, the important results following from its recognition have been obscured and befogged by several conceptions and phrases relating to capital which have found acceptance among English economists.
Chief and foremost among these errors is the framing of a definition of capital so as to exclude the clear separation of productive goods and machinery, the economic means, from consumptive goods, the economic end. So long as a definition of capital is taken which includes any consumptive goods whatsoever, two results follow. One is a hopeless confusion in the commercial mind, for in commerce everything is capital which forms the stock or plant of a commercial firm, and nothing is capital which does not form part of such stock or plant. Secondly, to include under capital the food in the possession of productive labourers or any other consumptive goods is an abandonment of the idea of consumption as the economic end and a substitution of production.
If we follow Böhm-Bawerk and the Austrian economists in definitely refusing to include the consumptive goods of labourers as capital,[164] we get a conception of capital which is at once in accordance with the universal conception of commercial men, and which enables us to realise the vital relation between capital and consumption. We now see Capital in the form of stock and plant at each point in the industrial machine deriving its use and value from its contribution to the end, Consumption, and dependent for its quantity upon the quantity of Consumption. We have seen that a demand for commodities is the true and exact determinant of the quantity of capital at each industrial stage. It is therefore the determinant of the aggregate of wealth which can function as useful forms of capital in the industrial community at any given time. The aggregate of plant and stock which constitute the material forms of capital at the points A, B, C, D, E must in a properly adjusted state of industry have an exact quantitative relation to the consumption indicated by F. If F increases, the quantity of forms of capital at A, B, C, D, E may severally and collectively increase; if F declines, the useful forms of capital at each point are diminished. Since we have seen that the sole object of saving from the social point of view is to place new forms of capital at one of the points A, B, C, D, E, it is evident that the amount of useful saving is limited by the rate of consumption, or financially, by the amount of "spending." Where there is an improvement in the general productive power of a community, only a certain proportion of that increased power can be economically applied to "saving"--_i.e._, to the increase of forms of capital; a due proportion must go to increased spending and a general rise in consumption.