_X_. True, Philebus, he has done so; and he _now_ holds that labor is invariable, supposing that his opinions have not altered within the last twelve months. But he was so far from holding this in 1820 (at which time it was that he chiefly insisted on the distinction between nominal and real value), that he was not content with the true arguments against the possibility of an invariable value, but made use of one, as I shall soon show you, which involves what the metaphysicians call a _non-ens_--or an idea which includes contradictory and self-destroying conditions. Omitting, however, the inconsistency in the idea of _real_ value as conceived by Mr. Malthus, there is this additional error engrafted upon the Smithian definition, that it is extended to "the necessaries and conveniences of life" in general, and no longer confined exclusively to labor. I shall, therefore, as another case for illustrating and applying the result of our dispute, 2. Cite a passage from Mr. Malthus' "Political Economy" (p. 59): "If we are told that the wages of day-labor in a particular country are, at the present time, fourpence a day, or that the revenue of a particular sovereign, seven or eight hundred years ago, was four hundred thousand pounds a year, these statements of nominal value convey no sort of information respecting the condition of the lower class of people in the one case, or the resources of the sovereign in the other. Without further knowledge on the subject, we should be quite at a loss to say whether the laborers in the country mentioned were starving or living in great plenty; whether the king in question might be considered as having a very inadequate revenue, or whether the sum mentioned was so great as to be incredible. [Footnote: Hume very reasonably doubts the possibility of William the Conqueror's revenue being four hundred thousand pounds a year, as represented by an ancient historian, and adopted by subsequent writers.--Note of Mr. Malthus.] It is quite obvious that in cases of this kind,--and they are of constant recurrence,--the value of wages, incomes, or commodities, estimated in the precious metals, will be of little use to us alone. What we want further is some estimate of a kind which may be denominated real value in exchange, implying the quantity of the necessaries and conveniences of life which those wages, incomes, or commodities, will enable the possessor of them to command."