60. This being the nature of labour, the "Cost" of anything is the quantity of labour necessary to obtain it;—the quantity for which, or at which, it "stands" (constant). It is literally the "Constancy" of the thing;—you shall win it—move it—come at it, for no less than this.
Cost is measured and measurable (using the accurate Latin terms) only in "labour," not in "opera."[26] It does not matter how much work a thing needs to produce it; it matters only how much distress. Generally the more the power it requires, the less the distress; so that the noblest works of man cost less than the meanest.
True labour, or spending of life, is either of the body, in fatigue or pain; of the temper or heart (as in perseverance of search for things,—patience in waiting for them,—fortitude or degradation in suffering for them, and the like), or of the intellect. All these kinds of labour are supposed to be included in the general term, and the quantity of labour is then expressed by the time it lasts. So that a unit of labour is "an hour's work" or a day's work, as we may determine.[27]
61. Cost, like value, is both intrinsic and effectual. Intrinsic cost is that of getting the thing in the right way; effectual cost is that of getting the thing in the way we set about it. But intrinsic cost cannot be made a subject of analytical investigation, being only partially discoverable, and that by long experience. Effectual cost is all that the political Economist can deal with; that is to say, the cost of the thing under existing circumstances, and by known processes.
Cost, being dependent much on application of method, varies with the quantity of the thing wanted, and with the number of persons who work for it. It is easy to get a little of some things, but difficult to get much; it is impossible to get some things with few hands, but easy to get them with many.
62. The cost and value of things, however difficult to determine accurately, are thus both dependent on ascertainable physical circumstances.[28]
But their price is dependent on the human will.
Such and such a thing is demonstrably good for so much. And it may demonstrably be had for so much.
But it remains questionable, and in all manner of ways questionable, whether I choose to give so much.[29]