Two, ostensibly different, versions of the social contract appear in Hobbes’s Leviathan, a commonwealth by institution and one by acquisition. These versions unexpectedly converge in chapter 20 with his remarkable claim that both commonwealths have the same rights and consequences of sovereignty. I argue that the first of these versions gives rise to a disjunction that logically commits Hobbes to either an impotent state or a Thrasymachean styled tyranny. After this, I describehow he tries to distance himself from the unsettling (...) implications of this disjunction by conflating two importantly different ideas, authorization and empowerment. Next, I explain how this conflation undermines his empowerment thesis for the first version, a difficulty further compounded by the failure of the jus naturalis to supply a normative foundation for this form of commonwealth. I then briefly detail his account of the second version and explain why a Thrasymachean styled tyranny emerges as the only possibility in a commonwealth by acquisition. Finally, after conceding a measure of plausibility to his claim of equivalency for his two forms of commonwealth, I conclude that Hobbes’s commitment to a coalescence of his two versions in chapter 20 effectively transforms his theory of a social contract into a defense of tyranny. (shrink)