What is the argument from relativity?

J. L. Mackie, answered from the texts and cited to the page.

J. L. Mackie answers

The argument from relativity takes as its premiss the well-known variation in moral codes across societies and historical periods, and the differences in moral belief between groups and classes within a single community.¹ That variation is, by itself, merely a fact of anthropology — it entails nothing directly about whether moral judgements are objectively true or false.

The indirect force it carries is this: radical differences in first-order moral judgements make it difficult to treat those judgements as apprehensions of objective truths.² But the argument is not simply that people disagree. Disagreement in history or biology or cosmology does not show there are no objective facts in those fields.³ What distinguishes the moral case is the causal story.

Scientific disagreement arises from speculative inference on inadequate evidence; moral disagreement seems instead to reflect people's adherence to different ways of life. The connection runs that way: people approve of monogamy because they participate in a monogamous way of life, not the other way round.⁴ The variations in moral codes are more readily explained by the hypothesis that they reflect ways of life than by the hypothesis that they express perceptions — most of them seriously inadequate and badly distorted — of objective values.⁵

The objectivist has a standard reply: what carries objective validity is not specific rules but very general principles — universalizability, or some utilitarian principle — which, married to differing circumstances and social patterns, generate the observed variation in specific codes.⁶ This is a partial counter, and I grant it partial force.

But it requires the objectivist to say that objective moral character attaches immediately only to these abstract principles, while all more specific judgements are valid only derivatively and contingently. And much of what ordinary moral thought treats as basic is not covered by such principles at all — what Hare calls ideals, or less kindly, fanaticism.⁷

That is why I call the argument from relativity the weaker of the two main supports for moral scepticism. It has genuine force, but a determined objectivist can always say that divergent societies simply perceive objective values with varying degrees of accuracy. The argument from queerness is where the real weight falls: if there were objective values, they would be entities of a very strange sort, utterly different from anything else in the universe, and awareness of them would require a faculty of moral perception equally unlike anything we otherwise possess.⁸ Relativity is evidence; queerness is the deeper problem.

Sources

1. The argument from relativity has as its premiss the well-known variation in moral codes from one society to another and from one period to another, and also the differences in moral beliefs between different groups and classes within a complex community.

   Ethics, Inventing Right and Wrong, pp. 33–34

2. radical differences between first order moral judgements make it difficult to treat those judgements as apprehensions of objective truths.

   Ethics, Inventing Right and Wrong, pp. 33–34

3. Disagreement on questions in history or biology or cosmology does not show that there are no objective issues in these fields for investigators to disagree about.

   Ethics, Inventing Right and Wrong, pp. 33–34

4. it is that people approve of monogamy because they participate in a monogamous way of life rather than that they participate in a monogamous way of life because they approve of monogamy.

   Ethics, Inventing Right and Wrong, pp. 33–34

5. the actual variations in the moral codes are more readily explained by the hypothesis that they reflect ways of life than by the hypothesis that they express perceptions, most of them seriously inadequate and badly distorted, of objective values.

   Ethics, Inventing Right and Wrong, p. 34

6. the items for which objective validity is in the first place to be claimed are not specific moral rules or codes but very general basic principles which are recognized at least implicitly to some extent in all society.

   Ethics, Inventing Right and Wrong, p. 34

7. these are very far from constituting the whole of what is actually affirmed as basic in ordinary moral thought. Much of this is concerned rather with what Hare calls 'ideals' or, less kindly, 'fanaticism'.

   Ethics, Inventing Right and Wrong, p. 34

8. If there were objective values, then they would be entities or qualities or relations of a very strange sort, utterly different from anything else in the universe. Correspondingly, if we were aware of them, it would have to be by some special faculty of moral perception or intuition, utterly different from our ordinary ways of knowing everything else.

   Ethics, Inventing Right and Wrong, pp. 35–36