My commentators have raised many important questions about, and made some very forceful objections to, what I have had to say in these lectures. I can only wish that I could give satisfactory responses to them all. In what follows, I address just a few of the points which they have raised. Specifically, in section 11 address the question why we must will in accordance with a universal law. In section 2 I discuss some ways in which, according to my commentators, my account of obligation departs from Kant's, to its detriment, and I try to defend myself both against the claims of departure and of detriment. In section 3 I discuss the status of desire, both in Kant's account and in my own. In section 4 I take up the question whether my focus on the idea of identity makes my account of moral motivation unattractively egoistic. Finally in section 5 I consider some issues about the relationship between giving a psychological explanation of the sense of obligation, and giving a justification of obligation itself.

AN OLD QUESTION RAISED AGAIN: THE UNIVERSALIZABILITY REQUIREMENT

Near the beginning of lecture 3 (3.2.3), I cited the argument by which Kant undertakes to establish that we must submit our maxims to a test of universalizability.