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. While staying within the accepted interpretations of the rule, he changes the strike zone every three innings; he starts with a widest zone, goes to the narrowest one, and then returns to a widest one. If he changes without regard to which team benefits or is harmed by this change, then he is impartial with regard to the two teams in calling balls and strikes. Because he does not treat like cases alike—that is, he calls balls and strikes differently in the first and fifth innings—he is a bad umpire, but he is still completely impartial with regard to the two teams with respect to calling balls and strikes. He is inconsistent, but inconsistency should not be confused with impartiality. A good umpire must be consistent as well as impartial. An inconsistent umpire will be suspected of not being impartial, but when the disgruntled umpire is not influenced at all by who is benefited or harmed, he remains impartial with respect to calling balls and strikes with regard to the two teams.
A person is impartial with regard to a group in a specified respect insofar as that person acts impartially in that respect with regard to that group. The basic concept of impartiality is defined as follows:
A is impartial in respect R with regard to group G if and only if A's actions in respect R are not influenced at all by which member(s) of G are benefited or harmed by these actions.
A teacher can be impartial with regard to a group G—for example, the students in her class in respect R; or, for example, grading their exams—but not impartial in a different respect, such as calling on them in class, for she may favor boys over girls in this respect. Two umpires, both consistent and impartial with regard to two teams, need not be impartial with regard to pitchers and batters. If one prefers a higher scoring game and the other a lower scoring one, they may, within the accepted interpretations, call some pitches differently. Both show partiality toward pitchers or toward batters, but both are still impartial with regard to the two teams.
Some contemporary consequentialists claim that morality requires impartiality whenever any sentient being's interests are involved. However, not only is there disagreement about whether all sentient beings are included in the group toward which morality requires impartiality, it is generally recognized that even with agreement about the group, morality does not require impartiality with respect to all actions affecting people's interests. It is generally agreed that morality does not even require impartiality when following moral ideals—for example, relieving or preventing pain, or helping the needy. Unless one does not act on these ideals at all, it is impossible to act on them impartially even with regard to all moral agents; no one can relieve or prevent pain impartially with regard to all moral agents. The only respect in which morality requires impartiality is with respect to violating moral rules—for example, those rules prohibiting killing, causing pain, deceiving, and breaking promises. It is only with regard to these kinds of moral rules—those that can be formulated as prohibitions—that it is humanly possible to act impartially with regard to a group large enough to be an appropriate group.
The examples of the teacher and umpire show that the group with regard toward which impartiality is usually required is often small and usually does not include the agent. The impartiality required by morality differs from this kind of impartiality in that it requires impartiality with respect to violating a moral rule toward a group composed of at least all moral agents, including the person violating the rule. Morality requires impartiality with regard to those moral agents affected by a violation of a moral rule—for example, being partial toward friends is not morally allowed. It also requires impartiality with respect to whether one can violate a moral rule; that is, it is not morally allowed to violate a rule in circumstances if it would be irrational to be willing for everyone to know that they are allowed to violate the rule in those same circumstances.
Sometimes all impartial rational persons favor violating a moral rule—for example, deceiving a hired killer in order to save an innocent person's life. Because morality always requires impartiality with respect to violating moral rules, it must be possible to violate a moral rule and still be acting impartially in this respect. This kind of impartiality can be achieved by violating a moral rule only when one would be willing for everyone to know that they are allowed to break the rule in the same circumstances. This achieves Kant's point about morality not allowing a person to make special exceptions for herself without creating the kinds of problems caused by the claim that morality requires acting on the categorical imperative.
Kant claims that morality requires that the group with regard to which one must be impartial with respect to violating a moral rule include only moral agents, that is, those persons who are required to act morally. Jeremy Bentham claims that the group includes all sentient beings. Most people, including most philosophers, do not agree with either Kant or Bentham; almost all want to include infants and children in the group toward which morality requires impartiality, but there is considerable disagreement about whether morality requires impartiality with regard to fetuses or to nonhuman animals. However, many who think that morality does not require impartiality with regard to nonhuman animals hold that morality does provide some protection to sentient nonhuman animals.
Because the concept of impartiality presupposes that there be some group with regard to which one is impartial, it does not make sense to claim that there is an impartial method for picking the group with regard to which morality requires impartiality. Recognizing that rational persons can differ about the composition of the group with regard to which morality requires them to be impartial helps explain the moral disputes concerning abortion and the treatment of animals. Morality limits the freedom of moral agents, so that the larger the group with regard toward which morality requires impartiality with respect to violating a moral rule, the greater the limitation on the freedom of moral agents. A rational person can rank this freedom of moral agents higher than the welfare of nonmoral agents or vice versa. The former is more likely to hold that morality does not require impartiality with regard to nonmoral agents, whereas the latter may hold that it does.
Even when there is agreement about the composition of the group with regard to which morality requires impartiality with respect to violating a moral rule, rational persons who are impartial with regard to all members of this group can still disagree. Because rational persons can rank the various evils—for example, death, pain, and disability—differently, one impartial rational person can favor everyone knowing that they are allowed to break a rule in circumstances in which another impartial rational person would not favor this. Impartiality does not require unanimity, as some philosophers such as Kant and Rawls seem to claim. If it did, then assuming that all Supreme Court justices know all of the relevant information, and do not suffer from any other mental dysfunction, one would be forced to hold that whenever the United States Supreme Court issues a split decision, at least one justice is not impartial.
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Kant, Immanuel. Grounding for the Metaphysics of Morals. 1785. Many editions.
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Rawls, John. A Theory of Justice. Cambridge, MA: Harvard University Press, 1971.
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Bernard Gert (1996, 2005)