Kant’s political theory stands in the social contract tradition, but departs significantly from earlier versions of social contract theory. Most importantly Kant holds, against Hobbes and Locke, that we have not merely a pragmatic reason but an obligation to exit the state of nature and found a state. Kant holds that each person has an innate right to freedom, but it is possible to simultaneously honor everyone’s right only under the rule of law. Since we are obligated to respect each person’s right to freedom, and can do so only in a state, we are obligated to submit to the authority of the state if we have one, and to establish one if we do not. In the first half of the essay I reconstruct this argument in more detail. In the second half I survey four points of controversy: (i) What is the relationship between Kant’s political philosophy and his moral philosophy? (ii) How does the innate right to freedom support the postulate that we are permitted to acquire property and other private rights? (iii) How does the postulate support an obligation to found the state? (iv) How should we understand Kant’s views about political revolutions?