There is a kind of power no one should have over anyone else, even if they don’t do anything with this power, or even if they only use this power for good. The republican tradition of political philosophy calls this kind of power domination. Here, I develop a theory of domination, and use this theory to advance our understanding of political legitimacy and justification. My account of domination refines recent neo-republican attempts to identify dominating social power with the capacity to (...) interfere arbitrarily with the choices of others. I argue that this capacity is not sufficient for domination. Instead, domination requires that one agent possess “impositional” power over someone else: power enough to make their refusal to cooperate more costly than cooperation across a wide range of forms that cooperation might take. But not all impositional power is domination; impositional power is domination to the extent that those wielding it do so in “deliberative isolation”—in accord only with their own sense of what’s best. The nature of domination, what it takes to minimize it, and its connection to deficits in political values like freedom and equality, are the subject of Chapter 2. The remainder of the dissertation uses the results of that chapter to construct a non-voluntarist alternative to the standard liberal account of how to reconcile political power with freedom and equality. Chapters 3 and 4 show how consent—actual or hypothetical—is not necessary to legitimize political power. What is necessary is that such power enable us to fulfil our duties against dominating others, while remaining accountable to us so that the state does not itself become a source of domination. How duties against domination can legitimize states is the primary subject of Chapter 3. Chapter 4 turns to the question of what we owe our fellow citizens as we cooperate together in the task of holding the state accountable. The answer to this question amounts to a repurposing and reformulation of public reason liberalism. Adviser: Joseph Mendola. (shrink)