The Argument from Relativity

Back in the late '70's, in a book called Ethics:  Inventing Right and Wrong, John Mackie put forward an argument he called "The Argument from Relativity," and a lot of people have spilled a lot of ink over the years trying to figure out what to say about it.  He doesn't put things in quite this way, but still I think it's fair to say the idea is basically this: 

(1) People disagree about the answers to ethical questions.

(2) (1) is better explained by the fact that people's moral views reflect their different ways of life than by the hypothesis that they express "perceptions, most of them seriously inadequate and badly distorted," of the objective truth

(3) So we ought to believe the first explanation.

Recently while in conversation with a friend, it occurred to me that there is a pretty straightforward objection to this argument:  it's not clear to me that the hypotheses Mackie mentions in (2) are mutually exclusive.  Mightn't it be the case that the perceptions of some of the parties to the dispute are badly distorted precisely because of their way of life?  Perhaps it is only with the right kind of upbringing, or in the right cultural context, that one can come to perceive the moral truth.  (Presumably this is what Aristotle would say were he and Mackie somehow to find themselves in conversation.)  And if it might, then Mackie's (2) presents us with a false choice, and we needn't accept his argument's skeptical upshot.  Instead we can simply grant his claim that people's ethical views seem to reflect their ways of life to at least some extent but still insist that the claims made by the parties to an ethical dispute express mostly distorted perceptions of the objective ethical truth.

It may be that this is a bit of a cheap shot, since in fact it might better reflect Mackie's thought if, instead of (2), I were to substitute (2*)

(2*) (1) is better explained by saying that ethical claims express commitment to a moral code rather than potentially true claims about the objective ethical facts.

But (2*) is obviously false, since the claim that ethical claims express commitment to a moral code does not explain (1) but rather entails its falsity.  This is because, if that is true, then if one person says that abortion is always wrong and another says that sometimes it's okay, they're not actually disagreeing as to whether or not some claim is true but rather just expressing different commitments.  The situation is basically the same as one where one person says he's made it his policy not to wear patterned ties and another says that his is to wear only patterned ties, which is obviously not a case of disagreement about what sort of ties one should wear.  It that's right, then the argument's not sound and perhaps not even valid.  (The issue hinges on whether or not you think every claim follows from a contradiction.  If that's right, then a suitably revised version of (3) does actually follow from (1) and (2*), so the argument is valid.)

Or maybe Mackie's thought was instead that

(2**) (1) is better explained by saying that ethical claims are basically claims about what is or isn't allowed  by some moral code we can have no reason to accept (so that their truth is in this sense relative to an arbitrary code) rather than potentially true claims about the objective ethical facts.

But, again, this doesn't help Mackie.  If ethical claims were relative in this sense, then the only kinds of ethical disagreements that would be possible would be disagreements about what was or was not allowed by a particular code, so that ethical disagreements would look pretty much the same as disagreements about which moves are allowed in chess.  There could be no disagreements about which standards to accept because, on this view, it does not make sense to ask which moral code is true, just as it doesn't make any sense to ask which set of rules is the right one for chess.  There is no right or wrong set of rules:  it's just that people who use different rules are not playing chess.  But, for precisely that reason, (2**) seems actually a pretty bad explanation of (1), since many moral disagreements seem to be disagreements about which standards to accept.  So if (2**) was Mackie's idea, then, again, it appears that his argument doesn't support any skeptical conclusions.