It would, then, be a sufficient answer to those who attack interest, and propose to transfer it from its present recipients to the state, to elucidate, as has here been done, the two following points: firstly, that to interest as a means of enjoying wealth--the right to such enjoyment itself not being here disputed--the only alternative is a system which would thus prove fatal to everybody; and, further, that, conversely, the enjoyment of wealth through interest not only possesses this negative advantage, but is actively implicated in, and is the natural corollary of, that progressive accumulation of force in the form of productive machinery to which all the augmented wealth of the modern world is due. By the identification of the enjoyment of capital with the enjoyment of some portion of the products of it, the good of the individual capitalist is identified with the good of the community; for it will, in that case, be the object of all capitalists to raise the productivity of all capital to a maximum; while a system which would compel the possessor, if he is to enjoy his capital at all, to do so by diminishing its substance and allowing its powers to dwindle, would identify the only advantage he could possibly get for himself with the impoverishment of everybody else, and ultimately of himself also.
But the crucial facts of the case have not been exhausted yet. There are few phenomena of any complex society which are not traceable to more causes than one, or at least to one cause which presents itself under different aspects. Such is the case with interest. Its origin, its functions, and its justification, in the modern world, must be considered under an aspect, at which hitherto we have only glanced.
Throughout the present discussion we have been assuming that the questions at issue turn ultimately on the character of human motive. On both sides it has been assumed that men of exceptional powers will not produce exceptional amounts of wealth, unless they are allowed the right of enjoying some substantial proportion of it. This is a psychological truth which, together with its social consequences, has been dealt with elaborately in two of our earlier chapters. It was there shown that the production of exceptional wealth by those men whose peculiar powers alone enable them to produce it, involves efforts on their part which, unlike labour, cannot be exacted of them by any outside compulsion, but can only be educed by the prospect of a secured reward; and that this reward consists, as has just been said, of the enjoyment of a part of the product proportionate to the magnitude of the whole. But what the proportion should be, and in what manner it should be enjoyed, were questions which were then passed over. They were passed over in order that they might be discussed separately. It was pointed out, however, that the reward, in order to be operative, must be such as will be felt to be sufficient by these men themselves, and that its precise amount and quality can be determined by them alone--just as, if what we desire is to coax an invalid to eat, we can coax him only with food which he himself finds appetising. Let us now take these questions up again, and examine them more minutely, and we shall find that interest is justified from a practical point of view by the fact that the enjoyment of capital by this particular means is not only the sole manner of enjoying it which is consistent with the general welfare, but also constitutes the advantage which, in the eyes of most great producers, gives to capital the larger part of its value, and renders the desire of producing it efficient as a social motive.