Abstract
If self-determination enables one to know truths and rule oneself, then it’s central to metaphysics and ethics because metaphysics concerns truths, and ethics grasps good actions requiring self-rule. Aristotle and Mencius agree about the relation between metaphysics and ethics. Nevertheless, closer examination shows differences in their conceptions of the self, how it knows truths, the nature of truth, and the effectiveness of the wise/virtuous on the world. Given the significance of self-determination to theory and practice, comparing Mencius’s and Aristotle’s views illuminates it and the challenges for each author’s view.