Singular prepossession of a man of genius, who does not see that to COMPARE, to APPRAISE, to APPRECIATE, is to MEASURE; that every measure, being only a comparison, indicates for that very reason a true relation, provided the comparison is accurate; that, consequently, value, or real measure, and value, or relative measure, are perfectly identical; and that the difficulty is reduced, not to the discovery of a standard of measure, since all quantities may serve each other in that capacity, but to the determination of a point of comparison. In geometry the point of comparison is extent, and the unit of measure is now the division of the circle into three hundred and sixty parts, now the circumference of the terrestrial globe, now the average dimension of the human arm, hand, thumb, or foot. In economic science, we have said after Adam Smith, the point of view from which all values are compared is labor; as for the unit of measure, that adopted in France is the FRANC. It is incredible that so many sensible men should struggle for forty years against an idea so simple. But no: THE COMPARISON OF VALUES IS EFFECTED WITH OUT A POINT OF COMPARISON BETWEEN THEM, AND WITHOUT A UNIT OF MEASURE,--such is the proposition which the economists of the nineteenth century, rather than accept the revolutionary idea of equality, have resolved to maintain against all comers. What will posterity say? I shall presently show, by striking examples, that the idea of the measure or proportion of values, theoretically necessary, is constantly realized in every-day life. % 3.--Application of the law of proportionality of values. Every product is a representative of labor. Every product, therefore, can be exchanged for some other, as universal practice proves. But abolish labor, and you have left only articles of greater or less usefulness, which, being stamped with no economic character, no human seal, are without a common measure,--that is, are logically unexchangeable. Gold and silver, like other articles of merchandise, are representatives of value; they have, therefore, been able to serve as common measures and mediums of exchange. But the special function which custom has allotted to the precious metals,--that of serving as a commercial agent,--is purely conventional, and any other article of merchandise, less conveniently perhaps, but just as authentically, could play this part: the economists admit it, and more than one example of it can be cited. What, then, is the reason of this preference generally accorded to the metals for the purpose of money, and how shall we explain this speciality of function, unparalleled in political economy, possessed by specie? For every unique thing incomparable in kind is necessarily very difficult of comprehension, and often even fails of it altogether. Now, is it possible to reconstruct the series from which money seems to have been detached, and, consequently, restore the latter to its true principle?