London School of Economics, UK Abstract. At the core of republican thought, on Philip Pettit’s account, lies the conception of freedom as non-domination as opposed to freedom as non-interference in the liberal sense. I revisit the distinction between liberal and republican freedom and argue that republican freedom incorporates a particular rule-oflaw requirement, whereas liberal freedom does not. Liberals may also endorse such a requirement, but not as part of their conception of freedom itself. I offer a formal analysis of this rule-of-law requirement and compare liberal and republican freedom on its basis. While I agree with Pettit that republican freedom has broader implications than liberal freedom, I conclude that we face a trade-off between two dimensions of freedom – scope and robustness – and that it is harder for republicans to solve that trade-off than it is for liberals.