Abstract
Kant’s ethics conceives of rational beings as autonomous–capable of legislating the moral law, and of motivating themselves to act out of respect for that law. Kant’s ethics also includes a notion of the highest good, the union of virtue with happiness proportional to, and consequent on, virtue. According to Kant, morality sets forth the highest good as an object of the totality of all things good as ends. Much about Kant’s conception of the highest good is controversial. This paper focuses on the apparent conflict between Kant’s claim that we are autonomous, and passages in which he seems to suggest that we require belief in the possibility of the highest good to motivate moral action. I distinguish three distinct versions of these problematic claims that seem to be present in Kant’s texts: that the highest good serves as (1) a motivational supplement to respect for the moral law, (2) a fundamental spring of right action, and (3) a condition of the bindingness of moral requirements. I argue that the texts are better interpreted to yield alternatives to (2) and (3) that do not conflict with our autonomy. I also argue that, properly understood, (1) does not conflict with our autonomy. In arguing for the last claim, I explore Kant’s notion of radical evil and its implications for human agency and virtue.