Lefebvre dedicated a great deal of his philosophical writings to understanding the importance of (the production of) space in what he called the reproduction of social relations of production. This idea is the central argument in the book "The Survival of Capitalism", written as a sort of prelude to (1974) ("The Production of Space"). These works have deeply influenced current urban theory, mainly within human geography, as seen in the current work of authors such as David Harvey, Dolores Hayden, and Edward Soja, and in the contemporary discussions around the notion of spatial justice. Lefebvre is widely recognized as a Marxist thinker who was responsible for widening considerably the scope of Marxist theory, embracing everyday life and the contemporary meanings and implications of the ever-expanding reach of the urban in the western world throughout the 20th century. The generalization of industry, and its relation to cities (which is treated in ), "The Right to the City" and "The Urban Revolution" were all themes of Lefebvre's writings in the late 1960s, which was concerned, among other aspects, with the deep transformation of "the city" into "the urban" which culminated in its omnipresence (the "complete urbanization of society").