The Root of Friendship addresses the connections between self-love and self-governance in the thought of St. Thomas Aquinas and defends three related theses. First, Aquinas's account of proper self-love is a description of the nature and importance of a person's subjective self- experience. Second, his notion of self-governance cannot be understood fully unless we grasp its basis in self-love. Finally, his account both satisfies contemporary conditions of relevance for self-governance and offers attractive solutions to issues raised in analytic discussions on such matters.