quantity of labor-time with regard to all commodities. The same exchange values are now estimated in greater or smaller quantities of gold than before, but they are estimated in proportion to the magnitude of their values, and consequently retain the same proportion to each other. The ratio 2 ÷ 4 ÷ 8 remains the same when expressed as 1 ÷ 2 ÷ 4 or as 4 ÷ 8 ÷ 16. The change in the quantity of gold in which exchange values are estimated with a variation in the value of gold, interferes as little with the function of gold as a measure of value, as the fifteen times smaller value of silver as compared with that of gold interferes with the performance of that function by the latter. Since labor-time is the common measure of gold and commodities, and since gold figures as the measure of value only in so far as all commodities are measured by it, the idea that money makes commodities commensurable, is therefore a mere fiction of the process of circulation.[39] It is rather the commensurability of commodities as incorporated labor-time, that turns gold into money. Commodities enter the process of exchange in the concrete form of use-values. They are yet to be turned into the real universal equivalent through their alienation. The determination of their prices merely amounts to their ideal transformation into the universal equivalent, a process of equation to gold which is yet to be realized. But since commodities are, in their prices, transformed into gold only in imagination, or are converted only into imaginary gold, and since their money form is not differentiated as yet from their concrete selves, it follows that gold has also been turned into money only in imagination; it appears so far but as a measure of value, and in fact definite quantities of gold serve merely as names for certain quantities of labor-time. The form in which gold is crystallized in money always depends upon the way in which commodities express their own exchange value to each other. Commodities now confront one another in a double capacity: actually as use-values, ideally as exchange values. The twofold aspect of labor contained in them is reflected in their mutual relations; the special concrete labor being virtually present as their use-value, while universal abstract labor-time is ideally represented in their price in which commodities appear as commensurable embodiments of the same value―substance differing merely in quantity.