Why do we sometimes prefer to consult the interests of others rather than our own interests? What is the relationship between selfishness and benevolence? Is altruism merely a mask for self-interest? At first sight these may appear to be empirical, psychological questions, but it is obviously the case that even if they are construed as such, the answers will depend on the meaning assigned to such key expressions as "self-interest," "benevolence," "sympathy," and the like. It is in connection with elucidating the meaning of such expressions that philosophical problems arise—problems that are of particular interest because we cannot understand such expressions without committing ourselves, in some degree, to some particular conceptual schematism by means of which we can set out the empirical facts about human nature. That there are alternative and rival conceptual possibilities is a fact to which the history of philosophy...