In the first place then, it is evident that we shall never get the price out of a relation between the cost and the satisfaction, so far as an individual at any given point of time, is concerned, inasmuch as there are always times when no object will give him satisfaction, as for example, as we have said, when he has just eaten his loaf and does not want another at any price, or when he has already bought all the household necessaries he requires, and does not want any more. In the former case, the unit of time necessary to get the market price would have to be continued and extended until his appetite came round again; and in the latter, he is no longer in the market as consumer, and so there cannot be in his case the relation between consumption and production necessary to determine a value. So far, then, it is evident that the relation must be one operating not at points of time, but in a continuous section of time, the length of which must correspond to the length of time necessary to make the article or commodity. If it took an individual a week to make his loaf of bread, it must last him a week, or he would starve in the end; if it took him a year to make a fishing rod and hook, the fish caught must, for the same reason, last him a year. And it is the same with a nation.

If it takes it a year to make a commodity in sufficient quantities to supply the wants of its people, so that any particular individual may be able to get it at the point of time at which he wants it, some other individual must put it on the market at that time; and therefore, in order that all the persons in the nation may have it as they want it, it must be put on the market at all the points of time. And from this, again, it follows that if the time is represented by a single revolution of the wheel, the only scientific terms in which Value can be expressed are those of the quantity and pace of commodities around a wheel; and that the problem of Value must be a relation between the quantity of a thing produced in a given time, and taken off in the same time; or if the quantity is fixed, on the relation between the time it takes to be put on the wheel, and the time it takes to be taken off; - all the costs, difficulties, and scarcities involved in the production of commodities, all the marginal utilities, personal satisfactions, etc., involved in their consumption, being summed up, as it were, and finding their expression, in the relative quantity or rapidity of their coming on and going off the wheel; all these elements which enter into it being submerged hence-forth, and so passing out of cognition or estimate, and replaced by the single category of units of economic quantity produced, as against units of economic quantity consumed, in given units of time.

If the commodity cannot be had in its usual quantity at a given moment of time, it means that some obstruction has taken place on the production side of the wheel - as a failure of crops, or the exhaustion of a mine, or an industrial 'corner,' - and as the two sides of the wheel must, as we have seen, keep time with each other, the consumption side must slow down to keep pace with it; and this it can only do by a rise of price. On the other hand, if the commodity is accumulating in greater quantities at any point than can be taken off, it means that the production side has been stimulated and is running too fast, - whether it be through better harvests, better machinery, new inventions, quicker and simpler processes, or what not, - and that the consumption side can only keep pace with it by a lowering of price, and so a carrying off of the congestion by a demand for a greater quantity at that lowered price; the pace being determined on the one side, as in a four-in-hand, by the slowest-footed of those engaged in the production of the commodity, that is to say by those who can only get their goods on the wheel under the greatest difficulties of labour and cost; and on the other, by those consumers who have the greatest hesitation, disinclination, or difficulty, in taking them off; all the rest of the producers benefiting by the increase of price caused by their slower-footed brethren, and all the consumers losing by it; while all the rest of the consumers gain by their own laggards, and all the producers lose by them.

From all of which it is evident, that the market price of any commodity is simply, in the language of the market, a relation between the quantity of its supply and the quantity of its demand at a given point of time, and at a given price; any change in the market price having the effect of determining, through the agency of the men on the axle, what amounts will be thrown on the wheel at its next revolution; and this, in turn, reacting on the price at which it will be taken off again; - the two sides of the wheel keeping time and step together as before. And from this, again, it follows that there is no normal, or natural, price of a commodity, depending on Labour-cost alone, as Mill and Ricardo thought, - and as distinguished from the separate market prices from day to day, which depend on the relation between the supply and the demand; - and further, that these market prices of a commodity, like the supply and demand of the commodity itself, are not fixed but fluid, attending the commodity around the wheel as its shadow, and keeping time and step with it as its lackey, just as we saw the paper credits do in a former chapter.