Is morality objective? A beginner’s guide to meta-ethics

Every few weeks one of my students in Bologna ends an argument with the same sentence: "Well, that's just your opinion." Usually it is said with some heat, and usually the topic was something like whether it is wrong to humiliate a weaker classmate online. I have come to treat the sentence as an invitation rather than a dead end, because it is a philosophical claim. It belongs to meta-ethics, the part of ethics that asks not which acts are right or wrong, but what we are doing when we say that they are.

This guide sets out the main answers in plain terms. At the end I will say where I think my student's sentence goes wrong, and where it does not.

Three things a moral sentence might be doing

Take the sentence "cruelty is wrong". It might be doing one of three quite different jobs.

It might be stating a fact, as "iron rusts" states a fact: something true whether or not anyone believes it.

It might be reporting an attitude, as "I dislike anchovies" does: true about the speaker, not about anchovies.

Or it might not be reporting anything at all. It might be expressing a feeling, as booing does, or prescribing, as a command does.

Almost every position in meta-ethics is a way of choosing among these, or of combining them.

The realists

Moral realism says there are moral facts, and they hold independently of what anyone thinks. If every human being approved of torturing children for fun, it would still be wrong, and everyone would be mistaken. Most people's first instinct is realist.

Realists divide over what moral facts are. Non-naturalists such as G. E. Moore argued that goodness is a simple property that cannot be defined in natural terms. His "open question argument" runs like this: for any natural definition of good, say "what produces pleasure", it still makes sense to ask "but is what produces pleasure good?", which it would not if the definition were correct. Naturalists reply that moral facts are natural facts, perhaps facts about human flourishing or about what creatures of our kind need to live well.

Realism is not a modern European invention. Mencius, the Confucian philosopher of the fourth century BCE, argued that anyone who suddenly sees a small child about to fall into a well feels alarm and compassion, before any thought of advantage. He took this as evidence that the beginnings of morality are part of human nature itself. His great Confucian critic Xunzi disagreed: human nature left to itself is crooked, and goodness is the product of deliberate effort, teachers and ritual. Notice that Xunzi was not a sceptic about morality. He thought it real, but made, in the way a well-crafted pot is real and made.

God and goodness

My students meet the oldest question in this area in Plato's Euthyphro, where Socrates asks whether the pious is loved by the gods because it is pious, or is pious because the gods love it. Recast for a single God, it becomes: is an act good because God commands it, or does God command it because it is good?

Islamic theologians argued about a closely related question with great precision. The Mu'tazila held that acts have moral qualities that reason can know, and that God, being just, commands accordingly. Al-Ash'ari and his followers held that the moral status of acts depends on the divine command, and that unaided reason cannot establish it. Both sides were doing careful philosophy, and the dilemma is a challenge to be answered, not a knockdown argument against religious ethics.

Making, relativising, expressing

Constructivism says moral truths exist, but are constructed: they are what an ideal procedure of reasoning would produce, rather than facts waiting to be found.

Relativism says moral claims are true or false only relative to a culture's standards. Subjectivism makes them relative to the individual.

Emotivism, made famous by A. J. Ayer in Language, Truth and Logic (1936), says that "stealing is wrong" expresses disapproval, something like "stealing: boo!", and is neither true nor false. Prescriptivism, developed by R. M. Hare, treats moral claims as a special kind of universal command.

Error theory, defended by J. L. Mackie in Ethics: Inventing Right and Wrong (1977), takes a bolder line. Our moral claims do try to state objective facts, Mackie said, but there are no such facts, so all positive moral claims are false. He gave two arguments. The argument from queerness: objective values would be very strange things, facts that somehow demand action from anyone who grasps them, detected by some special faculty. The argument from relativity: moral codes vary widely between societies, and that is better explained by different ways of life than by some societies seeing the moral facts and others missing them.

My argument: what "that's just your opinion" gets wrong

Here is what I now tell my class.

First, disagreement alone does not show there is no fact of the matter. People once disagreed about the shape of the earth. The question is whether a moral disagreement survives once we correct for ignorance, error and self-interest, and a great deal of moral disagreement, looked at closely, turns out to be disagreement about facts or circumstances rather than about basic values.

Second, the student who says "that's just your opinion" usually means something admirable: that we should not impose our views on others, that we should be tolerant and humble. But tolerance is itself a moral value, and she is treating it as binding on me, not merely as her opinion. Relativism offered in the name of tolerance cannot, on its own terms, require anyone else to be tolerant.

Third, and here I must be fair, none of this proves realism. Mackie's queerness argument is serious, and philosophers such as Simon Blackburn have tried to show how an anti-realist can still say, sincerely, that cruelty is wrong and would be wrong whatever anyone thought. Constructivists offer another middle path. The honest conclusion is that our moral experience points towards something more than opinion, and that saying exactly what that something is remains one of the hardest problems in philosophy.

How to begin

Read the Euthyphro; it is short and rather funny. Read the passage in the Mencius about the child and the well, and Xunzi's chapter on human nature, which answers it. Then read the first chapter of Mackie's book. After each, ask which of the three jobs the author thinks a moral sentence is doing. That one question will carry you a long way.