" The lower strata of the middle class—the small tradespeople, shopkeepers, retired tradesmen generally, the handicraftsmen and peasants—all these sink gradually into the proletariat, partly because their diminutive capital does not suffice for the scale on which Modern Industry is carried on, and is swamped in the competition with the large capitalists, partly because their specialized skill is rendered worthless by the new methods of production. Thus the proletariat is recruited from all classes of the population. "

― Karl Marx , The Communist Manifesto