Impartiality is a more complex concept than is generally recognized. Judging a person to be impartial is not as straightforward as judging a person to have some moral virtue such as kindness or trustworthiness. People do not even understand what it means to claim that one is impartial unless they know both the group toward which that person is impartial and the respect in which one is impartial with regard to that group. The impartiality required by morality also requires a specification of the group toward which morality requires impartiality and the respect in which it requires impartiality with regard to that group.

The most common characterization of general impartiality is that it requires that like cases be treated alike. Almost all philosophers take this characterization as trivially true, but it is mistaken. Consider a baseball umpire who is upset because he believes that umpires are not appreciated...