---
title: Foundations of Ethics
sort: 100
section-id: ethics
description: Metaethics versus normative ethics, the question of moral realism, and why ethical theory matters for practical reasoning.
language: en
---

# Foundations of Ethics

Ethics is the branch of philosophy concerned with questions about value, obligation, and the good life. Before we can adjudicate between competing moral theories — utilitarian, Kantian, Aristotelian — we must first examine what kind of inquiry ethics is. This is the domain of *metaethics*.

## The Metaethical Questions

Metaethics asks: What is the nature of moral claims? When we say "Torturing innocents is wrong," are we:

1. Stating an objective fact about the world?
2. Expressing a subjective attitude?
3. Issuing a kind of command or prescription?
4. Doing something altogether different?

These are not merely academic quibbles. The answer constrains what normative ethics can hope to achieve. If there are no moral facts, then ethical argument collapses into persuasion. If there are moral facts but we cannot know them, then ethical confidence is always epistemically precarious.

## Moral Realism

Moral realists hold that there are objective moral facts — facts that hold independently of what any individual or culture believes. G.E. Moore (1903) argued that "good" is a simple, indefinable, non-natural property that we perceive through a kind of moral intuition.^[Moore, G.E. (1903). *Principia Ethica*. Cambridge University Press.]

Naturalistic moral realists, by contrast, identify moral properties with natural properties. Cornell realists such as Peter Railton and Richard Boyd argue that moral terms refer to natural facts about human flourishing, desire-satisfaction, or social coordination.^[Boyd, R. (1988). "How to be a Moral Realist." In Sayre-McCord (ed.), *Essays on Moral Realism*.]

The **open question argument** (Moore) challenges naturalism: for any natural property N, it is always an open question whether something that is N is thereby good. If "good" just meant "maximises pleasure," then "Is pleasure-maximising action good?" would be a tautology — but it is not. This suggests that moral properties are not identical to natural ones.

## Anti-Realist Positions

### Expressivism
A.J. Ayer's *Language, Truth and Logic* (1936) presented the classic emotivist thesis: moral statements are not truth-apt at all. "Stealing is wrong" means something like "Boo, stealing!" — it expresses disapproval rather than describing a fact.^[Ayer, A.J. (1936). *Language, Truth and Logic*. Gollancz.]

Simon Blackburn developed *quasi-realism* to address the main objection to expressivism: that moral statements appear in contexts (conditionals, embedded clauses) where purely expressive readings are implausible. "If stealing is wrong, then getting your brother to steal for you is also wrong" cannot mean "If boo stealing, then boo getting your brother to steal."

### Error Theory
J.L. Mackie (1977) accepted that moral statements purport to state facts but argued they are systematically false. There are no objective moral properties in the world. We are all making a kind of category error when we assert moral claims.^[Mackie, J.L. (1977). *Ethics: Inventing Right and Wrong*. Penguin.] Mackie's *argument from queerness* claims that objective moral properties would be entities of a very strange kind — utterly unlike anything in the natural world — and our capacity to know them would require an equally strange epistemic faculty.

### Constructivism
Kantian constructivists (Christine Korsgaard, John Rawls) occupy a middle position: moral truths are not mind-independent facts discovered by intuition, but neither are they merely expressions of attitude. They are constructed through procedures of rational reflection or agreement under idealised conditions. Moral facts are *the output* of a normative procedure, not independently existing objects.^[Rawls, J. (1980). "Kantian Constructivism in Moral Theory." *Journal of Philosophy*, 77(9).]

## Normative Ethics: An Overview

Normative ethics asks: what ought we to do, and why? Three traditions dominate:

| Tradition | Central Question | Key Figure |
|---|---|---|
| Consequentialism | What outcomes should we produce? | John Stuart Mill |
| Deontology | What duties bind us regardless of outcome? | Immanuel Kant |
| Virtue Ethics | What kind of person should I be? | Aristotle |

Each tradition is examined in subsequent chapters. Here we note that they often converge in practice while diverging in their theoretical foundations — a useful starting heuristic.

## Moral Epistemology

How do we come to know moral truths (assuming there are any)? Candidates include:

**Moral intuition** — Direct, non-inferential moral knowledge. Strong intuitions (that gratuitous cruelty is wrong) are treated as data points that any adequate theory must accommodate. The method of *reflective equilibrium* (Rawls) involves moving back and forth between intuitions and principles until they cohere.

**Moral perception** — On some realist accounts, we literally perceive moral properties as we perceive colours (though with a different faculty). This view faces difficulty explaining inter-subjective disagreement.

**Reason alone** — Kantians hold that moral knowledge is a priori, derived from pure practical reason. We shall examine this in detail in the chapter on deontology.

## The Fact-Value Distinction

Hume's famous observation — that we cannot derive an "ought" from an "is" — remains one of the most contested claims in metaethics.^[Hume, D. (1740). *A Treatise of Human Nature*, III.i.1.] If no purely factual description of the world entails a moral conclusion, then moral premises are always smuggled into ethical arguments. Naturalists must either deny the is-ought gap or explain why the gap does not undermine their position.

## Relativism and Universalism

*Cultural moral relativism* — the descriptive claim that moral codes vary across cultures — is well-documented. *Moral relativism* — the normative claim that what is right depends on cultural norms — is a separate and far more contested thesis. It generates self-refutation problems: if morality is relative, then the moral principle "we should not impose our moral views on other cultures" is itself only relatively binding.

Universalists hold that certain moral truths — concerning dignity, suffering, basic rights — apply to all humans in all contexts. The debate between particularism and universalism remains unresolved.

## Further Reading

- Parfit, D. (2011). *On What Matters*, Vols. I–II. Oxford University Press.
- Schroeder, M. (2010). *Noncognitivism in Ethics*. Routledge.
- Sayre-McCord, G. (ed.) (1988). *Essays on Moral Realism*. Cornell University Press.
