 Nagel doubts that anyone actually is a psychological egoist (1970: 84–85), but his major concern is to refute ethical egoism, by showing that altruism is a rational requirement on action. His idea is not simply that we ought in certain circumstances to help others for their sake; it is also that we are acting irrationally if we do not. That is because it is required of us as rational beings to view ourselves and others from what Nagel calls “the impersonal standpoint”. As he puts it, 