The power of one object to command another in exchange is influenced either by a change in the object itself, or by a change in the other. If we found a case where there was never a change in the first object itself, then we should have, in that first, a measure of natural or absolute as opposed to nominal or relative value, _i. e._ a measure of that value of an article which satisfies the “conditions of the supply” of it, and enables its production to be continued without loss to the producers. By “conditions of supply” is meant Ricardo’s “cost of production” with the addition of ordinary profits. No measure of market or relative values is possible; and to have a measure of natural value itself we must make two postulates,—that natural value depends on “labour and profits” (_sic_), on rent little if at all, and that the “wages” of labour are also the “value” of labour,—what labour is paid is also what labour will fetch. It is easy to apply the measure where _only_ labour is concerned, for then the labour that the things _cost_ is a sufficient measure; it would be evident, at any change, that the things had become cheaper, not the labour dearer. But in present society value is more complicated; labour is no doubt the chief source of it, but profits are a very considerable one.[587] The natural conditions of supply, however, may be stated in terms of labour, just as if labour had been the sole ingredient. This would give us a measure for the _same_ country at the same place and time. The total quantity of labour that an article cost, with the addition of ordinary profits stated in terms of labour, would be the same as that quantity of labour which an article would purchase in its natural value.