The book shares Žižek's central problem of how to revitalize the radical political left through theory. It initially follows the argument developed in The Ticklish Subject that contemporary leftist thought is divided by antagonism between a Marxist revolutionary politics founded on Enlightenment philosophy and a politics of identity founded on post-modern post-structuralism.

How Žižek used Lacan's theory of character structures is examined here to describe this theoretical deadlock and explain how the dominant contemporary ideologies of liberal tolerant multiculturalism and reactionary "pseudo-fundamentalism" compete to mobilize the individual subject's unconscious drive to enjoyment. The book thus emphasizes the moments in which Žižek hints that Lacanian theory may describe a practice that facilitates the resolution of antagonisms that placate radical leftist politics. It challenges prevalent interpretations of Lacanian ends of analysis, to ultimately connect the psychoanalytic cure to the leftist project of social and political liberation.

The Subject of Liberation argues that if Lacan is to be useful to leftist politics, then the left has to develop its own definitions of the post-analytic subject, and proposes one such definition developed out of Lacanian and Žižekian theory.