In this paper, I posit loneliness, as Hannah Arendt defines it in the final chapter of The Origins of Totalitarianism as the conceptual opposite of agency. I give a brief overview of Arendt's phenomenology of loneliness, which is the total loss of the common world—the state in which one is incapable of being an interlocutor, through thought, speech, or action, with others and, ultimately, incapable of appearing as an individual to others. Though loneliness is realised in its most extreme form in the concentration camps, it is a problem that haunts all human interaction. It is often very difficult, especially for marginalised and traumatised subjects, to give an account of themselves, indeed, to make any sense of their lives at all. I argue that this difficulty is not insurmountable and make the claim that ontological agency, understood as the appearance as oneself to others in the world (the exercise of self‐disclosure), is an irreducible and constant capacity of every individual, no matter how deeply silenced or oppressed she may have been. I argue, further, that ontological agency is a precondition for meaningful political agency, understood as the public articulation of a well‐formed opinion or judgment.