These equations simply signify that equal quantities of universal social labor-time are embodied in one yard of linen, two pounds of coffee, half a pound of tea, etc. But as a matter of fact the individual labors which are represented in these particular use-values, become universal, and, in that form, also social labor, only when they are actually exchanged for one another in proportion to the labor-time contained in them. Social labor-time exists in these commodities in a latent state, so to say, and is first revealed in the process of exchange. We do not proceed from the labor of individuals as social labor, but, on the contrary, from special labor of private individuals which appears as universal social labor only by divesting itself of its original character in the process of exchange. Universal social labor is, therefore, no ready-made assumption, but a growing result. And thus we are confronted with a new difficulty, that on the one hand commodities must enter the process of exchange as embodiments of universal labor-time, while, on the other hand, this embodiment of the labor-time of individuals as social labor-time is itself a result of the process of exchange. Every commodity becomes an exchange value by divesting itself of its use-value, or of its original nature. The commodity must therefore assume a double capacity in the process of exchange. But that second capacity of exchange value can appear only in the shape of another commodity, because only commodities confront each other in the process of exchange. How is a particular commodity to represent directly _materialized universal_ labor-time, or―to put it differently―how is individual labor-time, which is embodied in a particular commodity to be made directly universal in character? The concrete expression of the exchange value of a commodity, i. e., of every commodity as a universal equivalent, is represented in an endless series of equations, such as: 1 yard of linen = 2 lbs. of coffee. 1 yard of linen = 1/2 lb. of tea. 1 yard of linen = 8 lbs. of bread. 1 yard of linen = 6 yards of calico. 1 yard of linen = etc. The above form is theoretical in so far as commodities are only _thought of_ as definite quantities of materialized universal labor-time. But the capacity of a particular commodity to serve as a universal equivalent from a mere abstraction becomes a _social_ result of the process of exchange by a simple inversion of the above series of equations, viz.: 2 lbs. of coffee = 1 yard of linen. 1/2 lb. of tea = 1 yard of linen. 8 lbs. of bread = 1 yard of linen. 6 yards of calico = 1 yard of linen.