For we have not forgotten that our perpetual-motion schemers, in spite of all their searchings and gropings among the wheels of their machines, always missed the all-important element of friction, which the broader illumination afforded by a knowledge of general mechanical principles afterwards brought to light. And as in this volume I have contended that our symbol of the wheel, with its dynamical, not statical, method of approach, affords a parallel illumination for the science of Political Economy, my readers will naturally expect me to show what light, if any, it can throw on this perplexed problem of Value. And accordingly, without further ado, let us venture to put this problem of Value, like the rest, on our wheel; and after setting the wheel agoing, see what kind of solution it will turn out. But first, I must make some addition to the wheel, in order that the smaller complications may find a place for themselves on it, as a fisherman might do to his net when he was more than usually anxious that none of the smaller fishes should escape him.

Now the first addition we must make to our wheel - and without which, indeed, no solution of the detailed problems of Political Economy is possible, - is to furnish it not only with an axle like an actual wheel, but with spokes radiating from it on every side to every part of the circumference. On the axle, or central platform, are to sit all those who are engaged in organizing and controlling the mechanism both of the production and the consumption of wealth, - the bankers, the brokers, and the dealers of the central Corn, Metal, and other exchanges; the spokes being the feelers which keep them, as the central intelligence department of the whole, in instant touch with every part both of the Production and of the Consumption sides or aspects of the wheel. And the first advantage we propose to get for the science from this addition is, that it will separate at once all those economical or industrial transactions which are not strictly on the wheel at all - and which cannot therefore be admitted as the basis for arguments properly belonging to the science of Political Economy - for although in the form of business bargains, they often really belong to the domain of other sciences, like Psychology - from transactions strictly belonging to the science.

For, unless an article, or commodity, or service, has its place both on the Production and Consumption sides of the wheel, and so can come within the purview of the men on the axle, through their feelers at all points of the circumference, it cannot be said to be on the wheel at all as part of the legitimate subject-matter of Political Economy. And the first effect of this elaboration of our wheel will be to throw out of consideration as arguments, all analyses which would resolve the broad facts of industry - as, for example, the actual supply and demand of actual commodities, of which the men on the axle can keep track and register - into terms of the mere personal motives, caprices, or satisfactions, of individuals, which have induced them to make, or refrain from making purchases, to enter into industrial speculations or refrain from entering into them, etc.; - and for this reason, that the men on the axle can neither have any cognizance of the infinite variations of these motives, caprices, or satisfactions, or of their number or their strength, inasmuch as they have no record of them, and even if they had, would find them entirely unmanageable, requiring a book-keeping which would fill up the world with its ledgers and derange the human reason! It is as if they should convert a plain fraction, say 1/3, into its recurring decimal .3333333, etc., where the procession of figures, like Macbeth's ghosts, might stretch out to the crack of doom before they could come down on the figure on which they were to pause, and of which they were in search.

Besides, there can be no advantage in it of any kind, inasmuch as all these miscellaneous motives of every degree of strength, which enter into the 'marginal' supply and demand of the article in question, would register themselves, after all, in the exact market price represented by the simple fraction J. On the other hand, should a single element of marginal utility or cost be left out, the result would no longer accurately register the actual value or market price. And therefore, although you can, if you please, speculatively resolve the relation between supply and demand into terms of these 'marginal' motives, costs, or satisfactions, like our recurring decimals; for practical purposes, they are as barren as the speculations of the Schoolmen as to the number of angels that could dance on the point of a needle; or as a calculation of the number of movements of a violinist's elbow in playing a concerto. And just as with the infinite forms of the crests and hollows of the waves of the sea, you can trust that they will find their level, on the simple law of gravitation, although you never could prove it by any possible detailed calculation of the ultimate, endless, intricacies of movement involved; so for practical purposes you can trust that the simple supply and demand of commodities or services, as measured in terms of money. is the ultimate scientific determinant of their relative value, into whatever differentiations of difficulty, cost, marginal utility, or personal satisfaction, you choose from psychological curiosity to resolve them.

For although money may not be the ideal measure of value, it is the only one at present practical or possible. And as the quantities of the supply of any article will always balance the quantity of its demand when once it is put on the wheel, inasmuch as Production and Consumption must always balance each other by a quickening or slowing of the whole wheel; and further, as the value of any article by itself, or its exchange value in reference to another, will, when it is converted into terms of money, always be determined by some relation between these quantities; it is evident that we need go no deeper than the simple relations of the quantity of the demand and supply of anything, whatever its ultimate nature may be, to solve the problem of Value, when once the article in question is put on the wheel, and the result registered on the axle in terms of money. And so all these dialectics of the academical Economists on the problem of Value, with their ultimate analyses of the respective factors into the brick-dust of degrees of satisfaction, or utility, 'margin of indifference,' 'final productivities,' etc., are so much surplusage, which not only confuse the problem, but add nothing of value to its solution.