Suppose, then, that suddenly, by a fortunate combination of efforts, by the division of labor, by the use of some machine, by better management of the natural resources,--in short, by his industry,--Prometheus finds a way of producing in one day as much of a certain object as he formerly produced in ten: what will follow? The product will change its position in the table of the elements of wealth; its power of affinity for other products, so to speak, being increased, its relative value will be proportionately diminished, and, instead of being quoted at one hundred, it will thereafter be quoted only at ten. But this value will still and always be none the less accurately determined, and it will still be labor alone which will fix the degree of its importance. Thus value varies, and the law of value is unchangeable: further, if value is susceptible of variation, it is because it is governed by a law whose principle is essentially inconstant,--namely, labor measured by time. The same reasoning applies to the production of the calendar as to that of all possible values. I do not need to explain how--civilization (that is, the social fact of the increase of life) multiplying our tasks, rendering our moments more and more precious, and obliging us to keep a perpetual and detailed record of our whole life--the calendar has become to all one of the most necessary things. We know, moreover, that this wonderful discovery has given rise, as its natural complement, to one of our most valuable industries, the manufacture of clocks and watches. At this point there very naturally arises an objection, the only one that can be offered against the theory of the proportionality of values. Say and the economists who have succeeded him have observed that, labor being itself an object of valuation, a species of merchandise indeed like any other, to take it as the principal and efficient cause of value is to reason in a vicious circle. Therefore, they conclude, it is necessary to fall back on scarcity and opinion. These economists, if they will allow me to say it, herein have shown themselves wonderfully careless. Labor is said TO HAVE VALUE, not as merchandise itself, but in view of the values supposed to be contained in it potentially. The VALUE OF LABOR is a figurative expression, an anticipation of effect from cause.