In Marxist theory, the Lumpenproletariat (ˌlʌmpənprəʊlɪˈtɛəriət) is the underclass devoid of class consciousness. Karl Marx and Friedrich Engels coined the word in the 1840s and used it to refer to the unthinking lower strata of society exploited by reactionary and counter-revolutionary forces, particularly in the context of the revolutions of 1848. They dismissed the revolutionary potential of the Lumpenproletariat and contrasted it with the proletariat. Among other groups, criminals, vagabonds, and prostitutes are usually included in this category. The Social Democratic Party of Germany made wide use of the term by the turn of the century. Vladimir Lenin (1870–1924) and Leon Trotsky (1879–1940) followed Marx's arguments and dismissed the revolutionary potential of the group, while Mao Zedong (1893–1976) argued that proper leadership could utilize it. The word Lumpenproletariat, popularized in the West by Frantz Fanon's The Wretched of the Earth in the 1960s, has been adopted as a sociological term. However, what some consider to be its vagueness and its history as a term of abuse has led to some criticism. Some revolutionary groups, most notably the Black Panther Party and the Young Lords, have sought to mobilize the Lumpenproletariat. Karl Marx and Friedrich Engels are generally considered to have coined the term Lumpenproletariat. It is composed of the German word Lumpen, which is usually translated as "ragged" and prolétariat, a French word adopted as a common Marxist term for the class of wage earners in a capitalist system. Hal Draper argued that the root is lump ("knave"), not lumpen. Bussard noted that the meaning of lump shifted from being a person dressed in rags in the 17th century to knavery in the 19th century. The American Heritage Dictionary of the English Language defines it as "the lowest stratum of the proletariat. Used originally in Marxist theory to describe those members of the proletariat, especially criminals, vagrants, and the unemployed, who lacked awareness of their collective interest as an oppressed class.