Kant’s justification of possession appears to beg the question (petitio principii) by assuming rather than proving the legitimacy of possession. The apparent question-begging in Kant’s argument has been recapitulated or exacerbated but not resolved in the secondary literature. A detailed terminological, textual, and logical analysis of Kant’s argument reveals that he provides a sound justification of limited rights to possess and use things (qualified choses in possession), not of private property rights. Kant’s argument is not purely a priori; it is (...) in Kant’s Critical sense ‘metaphysical’ because it applies the pure a priori ‘Universal Principles of Right’ to the concept of finite rational human agency. The application of this principle implicitly involves a ‘Contradiction in Conception’ test. I explicate this test in detail and show, inter alia, how Kant’s argument relates to the modern natural law tradition. I further argue that Kant’s ‘Universal Principle of Right’ is justified by appeal to a fundamental principle of justification, the Principle of Mutual Acceptability. This justification also suggests that the debate between Kantians and Utilitarians about whether human ‘dignity’ is an incommensurable value is moot because Kant’s test of the Categorical Imperative need not appeal to ‘dignity’. Finally, I show that the limited rights to possession and use justified by Kant’s argument suffice for his social contract argument for the legitimacy of the state. (shrink)