In addition to his readings of American feminist cultural theorist bell hooks (1952-2021), and French intellectual Michel Foucault (1926–1984), Soja's greatest contribution to spatial theory and the field of cultural geography is his use of the work of French Marxist urban sociologist Henri Lefebvre (1901–1991), author of The Production of Space (1974).

Soja focuses his critical postmodern analysis of space and society, or what he calls spatiality, on the people and places of Los Angeles.

In Thirdspace "everything comes together… subjectivity and objectivity, the abstract and the concrete, the real and the imagined, the knowable and the unimaginable, the repetitive and the differential, structure and agency, mind and body, consciousness and the unconscious, the disciplined and the transdisciplinary, everyday life and unending history.

"[12] Soja constructs Thirdspace from the spatial trialectics established by Henri Lefebvre in The Production of Space and Michel Foucault's concept of heterotopia.

He synthesizes these theories with the work of postcolonial thinkers from Gayatri Chakravorty Spivak to bell hooks, Edward Said to Homi Bhabha.

"[14] Thirdspace is a transcendent concept that is constantly expanding to include "an-Other," thus enabling the contestation and re-negotiation of boundaries and cultural identity.