But this transformation itself can only take place under certain circumstances that centre in this, viz., that two very different kinds of commodity possessors must come face to face and into contact, on the one hand, the owners of money, means of production, means of subsistence, who are eager to increase the sum of values they possess, by buying other people's labor power; on the other hand, free laborers, the sellers of their own labor power, and therefore the sellers of labor.