Roy Bhaskar and Ernesto Laclau met recently at the University of Essex in order to debate their respective approaches, critical realism and discourse theory. This chapter considers the conceptual overhaul both Bhaskar and Laclau have undertaken. It aims to develop the major points of philosophical contention between the two, that is Laclau's distinction between existence and being and Bhaskar's distinction between the intransitive and transitive dimensions. Discourse theory as espoused by Ernesto Laclau, and subsequently post-Marxism, is a very different response and is somewhat philosophically distant to critical realism. Laclau applies a deconstructive logic usually associated with Jacques Derrida to the realm of politics. For Laclau, the notion of discourse as developed in much contemporary thought has distant roots in the transcendental turn in modern philosophy, with an emphasis not primarily on facts but rather on their conditions of possibility. Both Bhaskar and Laclau have attempted to develop their own projects from inside and outside the Marxist tradition.