Why did Hume drop sympathy as a key concept of his moral philosophy, and why—on the other hand—did Smith make it into the ‘didactic principle’ of his Theory of Moral Sentiments? These questions confront us with the basic issue of ethical theory concerning human nature. My point in dealing with these questions is to show what views of human nature their respective choices involved. And my procedure will be to take a close look at the revisions they made to their (...) ethical theories to bring out the contrasting aspects of their views of human nature. (shrink)