How then does a sum of commodities, of exchange values, become capital? Thereby, that as an independent social power, i.e., as the power of a part of society, it preserves itself and multiplies by exchange with direct, living labour-power. The existence of a class which possesses nothing but the ability to work is a necessary presupposition of capital. It is only the dominion of past, accumulated, materialized labour over immediate living labour that stamps the accumulated labour with the character of capital.
