It is doubtful if we can escape this question in theory. The required standard may come as a more modest proposal than that of Adam Smith, but some means of comparing value, as significance (as Menger’s “_Bedeutung_”) in different times will always be desirable, to say the least. In the recent controversy over the question whether gold is a good standard of deferred payments, practical men decided for gold on other (and sufficient) grounds than any alleged invariability in value, but it was inevitable that the question should suggest itself: What does constitute the same _value_ in different times (_i. e._ under changed conditions of wealth)? It is the legitimate function of economic theory to wrestle with such questions, whether to conclude that an answer is impossible (for that would be a conclusion, hard to prove and of importance when proved) or that such and such a standard may be established. The present essay will not attempt the herculean dialectical labor of setting in order and criticising all that Smith, Malthus, and Ricardo wrote on this subject. The labor doctrine as a statical theory is a problem of sufficient proportions in itself to permit specializing upon it. A brief discussion however is added concerning what Malthus wrote upon the subject of the labor-command measure. In the first edition of his _Principles_, Malthus held that there is no question of possessing a perfect measure of value at different times, but there is a question of choice between various imperfect measures. He was apparently much impressed by the charge that the value of labor changes when the quantity of commodity (_i. e._ measured in physical units) which it commands, is altered. Accordingly he proposes to take labor and “corn” together, or a “mean between them” as a standard.[128] He proceeds upon the supposition that “when corn compared with labour is dear, labour compared with corn must necessarily be cheap. At the period when a given quantity of corn will command the greatest quantity of the necessaries, conveniences, and amusements of life, a given quantity of labour will always command the smallest quantity of such objects, (and _vice versâ_); ... If, then, we take a mean between the two, we shall evidently have a measure corrected by the contemporary variations of each in opposite directions.”[129] In this double standard a unit of labor is to be a _day_ of “common” labor. For the use of the standard some unit of corn is necessary. A _peck_ is selected. The reason given for this choice is that this amount may be considered “in respect to quantity as equivalent to a day’s labour.” Accordingly, “any commodity, which at different periods will purchase the same number of days’ labour and of pecks of wheat, or parts of them, each taken in equal proportions, may be considered, upon this principle, as commanding pretty nearly the same quantity of the necessaries, conveniences, and amusements of life; and, consequently,