Lumpenproletariat, (German: “rabble proletariat”), according to Karl Marx in The Communist Manifesto, the lowest stratum of the industrial working class, including also such undesirables as tramps and criminals. The members of the Lumpenproletariat—this “social scum,” said Marx—are not only disinclined to participate in revolutionary activities with their “rightful brethren,” the proletariat, but also tend to act as the “bribed tools of reactionary intrigue.”