The substitution of investment in the place of industry as the central and substantial fact in the process of production is due not to the acceptance of hedonism simply, but rather to the conjunction of hedonism with an economic situation of which the investment of capital and its management for gain was the most obvious feature. The situation which shaped the common-sense apprehension of economic facts at the time was what has since been called a capitalistic system, in which pecuniary enterprise and the phenomena of the market were the dominant and tone-giving facts. But this economic situation was also the chief ground for the vogue of hedonism in economics; so that hedonistic economics may be taken as an interpretation of human nature in terms of the market-place. The market and the "business world," to which the business man in his pursuit of gain was required to adapt his motives, had by this time grown so large that the course of business events was beyond the control of any one person; and at the same time those far-reaching organisations of invested wealth which have latterly come to prevail and to coerce the market were not then in the foreground. The course of market events took its passionless way without traceable relation or deference to any man's convenience and without traceable guidance towards an ulterior end. Man's part in this pecuniary world was to respond with alacrity to the situation, and so adapt his vendible effects to the shifting demand as to realise something in the outcome. What he gained in his traffic was gained without loss to those with whom he dealt, for they paid no more than the goods were worth to them. One man's gain need not be another's loss; and, if it is not, then it is net gain to the community. Among the striking remoter effects of the hedonistic preconception, and its working out in terms of pecuniary gain, is the classical failure to discriminate between capital as investment and capital as industrial appliances. This is, of course, closely related to the point already spoken of. The appliances of industry further the production of goods, therefore capital (invested wealth) is productive; and the rate of its average remuneration marks the degree of its productiveness.[34] The most obvious fact limiting the pecuniary gain secured by means of invested wealth is the sum invested. Therefore, capital limits the productiveness of industry; and the chief and indispensable condition to an advance in material well-being is the accumulation of invested wealth. In discussing the conditions of industrial improvement, it is usual to assume that "the state of the arts remains unchanged," which is, for all purposes but that of a doctrine of profits per cent., an exclusion of the main fact. Investments may, further, be transferred from one enterprise to another. Therefore, and in that degree, the means of production are "mobile." * * * * *