Asking what discursive conditions enabled the unchallenged reign of neoliberal capitalism in Eastern Europe after 1989, this dissertation argues that Stalinist philosophy leaves a silent yet powerful structuring legacy in post-socialist politics and intellectual discourse. Stalinist Marxism-Leninism has survived in the presumption that there is a necessary relationship between authoritarianism and politics on the left, and conversely, between democracy and free-market capitalism. Rejecting the premise that there is an inevitable, trans-historical relationship between socialism and authoritarianism, this project locates the historical juncture that sealed them together in the discursive production of Leninism and the doctrines of Dialectical Materialism and Historical Materialism during Stalinist Soviet Union. With a focus on socialist Bulgaria, the dissertation examines the political uses and material effects of the Stalinist ideologemes throughout the intellectual history of East-European Marxist thought. In addition, it retrieves Marxist humanist intellectual movements from the post-Stalinist 1960s and 1970s, which contested the legitimacy of the Stalinist doctrine. Challenging Marxism-Leninism's claim to the historical inevitability of state authoritarianism, they imagined a "third way" for socialism's future--a third way between liberal democracy and authoritarian socialism. In conclusion, the dissertation turns to the question of what possibility for politics on the left remains in the post-socialist historical conditions, a left that finds itself inevitably implicated in the histories of state socialisms. Redressing these foreclosures requires recovering the emancipatory ideas and practices out of the contradictory experiences of the socialist past and reformulating their critical potentials for the future.