This study examines the place of passion and emotion in Hannah Arendt’s political philosophy by analysing their role in shaping revolutionary action and determining its outcomes. It begins by distinguishing freedom as a foundational public practice from liberation as emancipation from constraint and necessity. Through a comparison of the French and American revolutionary experiences, the study demonstrates that the affective economy of revolution determines its capacity to establish a shared political realm. When the passion for freedom continues to guide action, the possibilities of political foundation are strengthened. When necessity, misery, pity, and anger prevail, however, revolution is drawn toward violence and terror. The study concludes that the failure of revolutions is associated with the transformation of their foundational passions into emotions that undermine plurality, the public realm, and political freedom, replacing collective action with the logic of need and the management of social suffering.