In sociology and political science, bourgeoisie (Fr.: [buʁ.ʒwa'zi] | Eng.: /bʊrʒwɑziː/) and the adjective bourgeois are terms that describe a historical range of socio-economic classes. Since the late 18th century in the Western world, the bourgeoisie describes a social class that is characterized by their ownership of capital and their related culture. In contemporary academic theories, the term bourgeoisie usually refers to the ruling class in capitalist societies. In Marxist theory, the abiding characteristics of this class are their ownership of the means of production.