These two classes, consisting of relatively few capitalists who own tools in the form of great machines that they did not make and that they cannot use, and of a vast army of wage workers who did make these machines and who do use them, but who do not own them—these two classes’ tool-owners and tool-users; that is to say, masters and slaves, exploiters and exploited; to put it into perfectly plain terms, robbers and robbed-these two economic forces whose interests ceaselessly clash, are pitted against each other in a mighty struggle for the mastery.