Is morality objective? · Quiz question 8/35

Opposite Alien Morals

Alien Morality and Moral Disagreement

Meet aliens who believe the exact opposite morality just as sincerely. Is there any way to say who's right? Moral disagreement and Moral Twin Earth.

As it appears in the quiz

We meet an alien civilization whose morality is the exact opposite of ours. They believe in their morals just as seriously as we do.

There's no objective way to decide whose morality is right.

Who came up with it

The classic argument from deep moral disagreement to anti-realism is J. L. Mackie's "argument from relativity" (1977): the wide variation in moral codes is better explained by different ways of life than by people perceiving objective moral facts. In the early 1990s, Terence Horgan and Mark Timmons used "Moral Twin Earth" — people who use "good" for a different set of things than we do — to argue against naturalist realism, since we still feel we'd genuinely disagree with them.

Original papers & key readings

What it's really asking

If you agreed, you think there's no neutral standard to decide between sincerely held moral systems. Science settles disputes with observation and experiment; morality seems to have no such referee — a big motivation for anti-realism.

Realists reply that disagreement doesn't mean there's no fact. Science had long disagreements too, and a lot of moral disagreement comes from factual mistakes, self-interest and bias. Robust realists like David Enoch say moral facts are indispensable to deliberation. Interestingly, many philosophers think that if the aliens really have pain and interests, there'd be common ground for judgment.

Where philosophers stand

Anti-realism / relativism (agrees)

There's no neutral way to settle deep disagreement. Morality is rooted in each community's way of life.

Key names: J. L. Mackie, Harman, Nietzsche

Moral realism (disagrees)

Disagreement doesn't prove there's no fact. One side — or both — may be wrong.

Key names: Derek Parfit, Enoch, G. E. Moore

Constructivism / rationalism

There are minimal principles any rational being must accept — aliens included.

Key names: Kant, Jürgen Habermas

Philosophers to check out

Sources