Many readers of Kant’s ethical writings take him to be primarily concerned with offering guidelines for action. At the least, they write about Kant as if this were the purpose of his ethical writings. For example, Christine Korsgaard, in her influential article Kant’s Analysis of Obligation: The Argument of Groundwork I, writes that, ‘‘the argument of Groundwork I is an attempt to give what I call a ‘motivational analysis’ of the concept of a right action, in order to discover what (...) that concept applies to, that is, which actions are right.’’ Similar comments are not hard to find in the secondary literature. This, however, is a fundamentally misguided way of reading Kant, since he repeatedly asserts that we do not need to do moral philosophy in order to discover which actions are right. We already know how to behave morally and do not need philosophers to tell us this. ‘‘Common human reason,’’ Kant argues, ‘‘knows very well how to distinguish in every case that comes up what is good and what is evil, what is in conformity to duty or contrary to duty.’’ Because people with pre-philosophical understanding know how to act morally, the purpose of moral philosophy cannot be to provide us with a set of rules for correct behavior. If we take Kant’s claims about common human reason seriously, then his aim in the Groundwork of the Metaphysics of Morals cannot be to discover which actions are right. (shrink)