In the sale C―M, as well as in the purchase M―C, two commodities, entities of exchange value and use-value, confront each other, but the exchange value of the commodity exists only ideally as price; while as regards gold, although it is really a use-value, its use-value is confined only to its being the bearer of exchange value and is, therefore, merely a formal use-value, having no relation to a real individual want. The antithesis of use-value and exchange value is thus distributed at the two extreme poles of C―M, so that the commodity confronts gold as a use-value which has yet to realize in gold its exchange value or its price, while gold confronts the commodity as an exchange value, whose formal use-value is yet to be realized in the commodity. Only through this duplication of the commodity as commodity and gold, and, further, through the twofold and polar relation by virtue of which each extreme represents but ideally what its opposite is in reality and is in reality what its opposite is only ideally―in short, only through the appearance of commodities as two-sided polar opposites are the contradictions solved that are inherent in the process of exchange. So far we have considered C―M as sale, as the conversion of commodity into money. But if we look at it from the other end, the same process will assume the form M―C, or purchase, i. e., the conversion of money into commodity. Sale is necessarily its opposite at the same time; it is the former if we look at the process from one end, and the latter if we regard the process from the other end. In practice this process differs only in that the initiative in C―M originates at the commodity end or with the seller, while in M―C it comes from the money end or the buyer. In describing the first metamorphosis of the commodity, its conversion into money as a result of the completion of the first phase of circulation C―M, we assume at the same time that another commodity has been converted into money and is now in its second phase of circulation, M―C. Thus we get into a vicious circle of assumptions. Circulation itself constitutes such a vicious circle. If we did not consider M in M―C as the result of a metamorphosis of another commodity, we would thereby take exchange out of the process of circulation. But outside of the latter the form C―M disappears and only two different Cs confront each other, say iron and gold, the exchange of which does not constitute a part of the process of circulation, being direct barter. Gold, at the source of its production, is a commodity like any other commodity. Its relative value and that of iron or of any other commodity is expressed here in quantities in which they are mutually exchanged. But in the process of circulation this operation is implied, the value of gold being already given in the prices of commodities. Nothing can, therefore, be more erroneous than the idea that gold and commodity enter into