 Capitalist exploitation thus consists in the forced appropriation by capitalists of the surplus value produced by workers. Workers under capitalism are compelled by their lack of ownership of the means of production to sell their labor power to capitalists for less than the full value of the goods they produce. Capitalists, in turn, need not produce anything themselves but are able to live instead off the productive energies of workers. And the surplus value that capitalists are thereby able to appropriate from workers becomes the source of capitalist profit, thereby “strengthening that very power whose slave it is” (Marx 1847: 40).