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. § 12. This will hardly be disputed, except by those who still follow Mill in maintaining that the whole of the current production could be "saved," with the exception of what was required to support the efficiency of labour, a doctrine to which even he could only give passing plausibility by admitting that the increased savings which resulted from an attempt to do this would take the shape of luxuries consumed by the said labourers--that is to say, would not be "savings" at all, but a transfer of "spending" from one class to another.[165] If capital be confined to commercial capital, and "saving" to the establishment of the forms of such capital, no one will deny that the quantity of "saving" which can be effectually done by a community at any time depends upon the current rate of consumption, or that any temporary increase of such saving must be justified by a corresponding future increase in the proportion of spending.[166]