Reflective Equilibrium

Core Idea

Reflective equilibrium is a method for ethical justification: revise and adjust moral judgments, principles, and background theory until they cohere into a stable, mutually supporting set. Unlike foundationalism (grounding ethics in basic intuitions) or simple coherentism (all beliefs must cohere), reflective equilibrium allows modification at any level to achieve fit. This models how moral thinking actually works—we shuttle between particular convictions and general theories, adjusting each in light of the other.

Explainer

Think about how you already reason morally. You have considered judgments — strong, relatively confident intuitions about particular cases: torturing children for fun is wrong, keeping a promise matters, saving five lives is better than saving one. You also have moral principles that generalize across cases: maximize welfare, respect persons as ends, treat like cases alike. Reflective equilibrium is the method of making these two levels cohere. When they conflict, you face a choice: revise the principle to fit the intuition, revise the intuition in light of the principle, or revise both toward a stable middle ground.

The method comes in two strengths. Narrow reflective equilibrium just seeks coherence between your particular judgments and your general principles — no outside theory required. Wide reflective equilibrium brings in a third level: background theories about the nature of morality, the purpose of moral reasoning, facts about human psychology, and metaethical commitments. Wide equilibrium is harder to achieve but more philosophically ambitious: it doesn't just ask "do my moral beliefs cohere?" but "does my whole moral worldview hang together?"

From your prerequisite work in moral reasoning methods, you know that both intuitionism (just trust strong intuitions) and pure theorizing (just apply the principle mechanically) have problems. Reflective equilibrium is a response to both failures. Pure intuitionism leaves you with no way to adjudicate between conflicting intuitions or extend your judgments to new cases. Pure principle-application can produce monstrous conclusions from seemingly plausible premises — the classic problem of tollensing the ponens: when an argument leads to a conclusion that seems clearly wrong, the right move is often to reject a premise rather than accept the conclusion.

The process is iterative, not algorithmic. Rawls, who developed the method most systematically, used it to derive the principles of justice: he started from considered judgments (slavery is wrong, fair procedures matter), extracted principles that would generate those judgments, checked them against other cases, revised, and repeated until reaching stable principles. The stability is not mere consistency — it requires coherence across levels and robustness against counterexamples. The method concedes that moral knowledge is not derived from unshakeable foundations but built up through disciplined mutual adjustment. This is what makes it a coherentist rather than foundationalist approach to moral epistemology.