In the former case money is the medium of exchange of commodities, in the latter the commodity helps money to become money. Money which appears merely as a means of circulation in the first form becomes an end in the second form; while commodity which appeared first as the end, now becomes but a means. Since money is itself the result of circulation C—M—C, the result of circulation appears at the same time as its starting point in the form M—C—M. While in the case of C—M—C the interchange of matter constituted the real import of the process, the form of the commodity resulting from this first process constitutes the import of the second process
In the form C—M—C the two extreme members are commodities of the same value, but qualitatively different use-values. Their mutual exchange C—C constitutes actual interchange of matter. In the form M—C—M the two extremes are gold and at the same time gold of equal value. To exchange gold for a commodity in order to exchange the commodity for gold, or if we consider the final result M—M, to exchange gold for gold, seems absurd.