Fourthly: In the _Measure of Value Stated and Illustrated_, I considered the value of commodities as, on an average, determined by the natural and necessary conditions of their supply. These conditions I stated to be the accumulated and immediate labour worked up in commodities with the ordinary profits upon the whole advances for the time that they were advanced. And it appeared, both in the early part of the discussion, and in the Table, that the quantity of labour which a commodity would ordinarily command must represent and measure the quantity of labour worked up in it with the addition of profits. It was certainly a very remarkable fact, that when Mr. Ricardo chose the labour worked up in commodities “as, under many circumstances, an invariable standard,” and rejected the labour which they would ordinarily purchase as subject to as many fluctuations as the commodities compared with it,[88] he should not have seen that the labour which a commodity will ordinarily command, necessarily involves his own proposition, with that addition to it merely which can alone make it correct; and that it is precisely because the labour which a commodity will ordinarily command measures the labour actually worked up in it with the addition of profits, that it is justifiable to consider it as a measure of value. If then the ordinary value of a commodity be considered as determined by the natural and necessary conditions of its supply, it is certain that the labour which it will ordinarily command is alone the measure of these conditions.