Meta-ethical theories - Intuitionism and knowing good
Intuitionism holds that basic moral truths can be known without defining goodness as a natural property. Its challenge is to explain this knowledge without confusing it with an unexamined feeling.
Simple goodness and basic truths
Moore treats good as a simple, indefinable, non-natural property. A simple property cannot be analysed into more basic components that state its meaning. His comparison with yellow illustrates the point: describing things that are yellow is different from analysing yellowness into a definition. Likewise, identifying good things does not define goodness.
This is a cognitive account. 'This is good' attributes a property and can be true or false; goodness does not become true merely because someone approves. It differs from naturalism in what sort of property is attributed, not in treating all moral claims as meaningless.
Intuitionism holds that some basic moral truths are self-evident. Adequately understanding such a truth can justify accepting it without deriving it from a further premise. Self-evident does not mean instantly obvious to everyone, immune to misunderstanding, or guaranteed whenever someone feels certain. Careful reflection may be needed to grasp a basic truth. The scholarly account of intuitionism distinguishes this epistemic claim from a mere hunch.
Moore's Principia Ethica, sections 10 and 13 supports indefinability and the distinction between basic judgements and proof. Do not infer that every practical decision is self-evident. Even if unnecessary suffering is bad, deciding what reduces suffering requires evidence and reasoning. Intuition supplies a proposed starting point, not automatic knowledge of every consequence.
Reflection and practical judgement
Basic moral knowledge can support reasoning about complex actions without making the final judgement immediate. In an original hypothetical case, an employer can prevent avoidable serious injury at modest cost. A person may judge the badness of needless suffering directly, yet must establish whether the injury is likely, whether the proposed prevention works and whether it causes other serious harms.
W. D. Ross offers a related intuitionist account of prima facie duties, including fidelity, justice, beneficence and avoiding harm. A prima facie duty is a genuine moral reason that can be outweighed, rather than a duty that merely appears genuine. An all-things-considered duty requires judgement where such reasons conflict. This illustrates intuitionism's diversity; Moore's account of good and Ross's account of duties should not be treated as identical.
Imagine an original conflict between keeping a promise to visit a friend and helping an injured stranger. Knowing that promises matter does not show that keeping this promise is decisive. The urgency of harm can provide a stronger reason. Neither the existence of duties nor their relative force can be settled by simply reporting which option feels attractive.
This gives intuitionism a way to preserve objective moral reasons while recognising practical complexity. Its difficulty is explaining how judgement reliably weighs competing reasons. A coherent argument must expose the conflict and defend the priority assigned, rather than call the conclusion 'self-evident' to prevent criticism.
Common sense and disagreement
Intuitionism fits a common-sense experience: people often seem to know that cruelty is wrong before they produce an elaborate theory. We usually argue as though someone can be mistaken about right and wrong, rather than treating every approval as equally authoritative. Basic moral understanding can explain why moral argument has starting points at all.
The critic asks whether this apparent knowledge is learned prejudice. Societies have confidently approved practices that others condemn. If certainty alone established truth, incompatible convictions would be equally justified. An appeal to intuition can also hide the interests of people with power by presenting their preferred view as what everyone naturally knows.
An intuitionist can reply that disagreement is compatible with knowledge: people disagree about many matters without making truth disappear. Poor information, confused concepts, self-interest or inadequate reflection can explain some disagreement. Carefully distinguishing a basic principle from its application can also expose an apparent conflict. Two people may agree that harm matters while disagreeing about whether a policy will cause it.
This reply succeeds only when reasons support the distinction. Calling all opponents confused would protect the theory by assertion. Persistent disagreement between informed, reflective people remains a challenge to explaining reliable access to moral truth. Common sense makes intuitionism plausible, but does not by itself establish that each claimed intuition is correct.
Knowing without a definition
Indefinability and unknowability are different claims. We can recognise a property without reducing it to a verbal definition; therefore Moore's rejection of naturalist definitions does not entail that 'good' has no meaning. Intuitionism proposes that understanding basic moral truths gives us knowledge of an objective non-natural value.
Its explanatory strength is preserving the force of moral criticism. The employer who approves avoidable injury can still be wrong; approval does not create goodness. Its cost is explaining how a non-natural property can be known. Ordinary observation tells us that workers are injured, but the account must explain how we grasp the value of preventing injury rather than simply learning an attitude toward it.
Naturalism offers publicly investigable properties and a closer link to empirical evidence. Intuitionism replies that reducing good to an observable property loses the distinctive evaluative question. The disagreement concerns whether moral understanding needs a natural definition, not whether either side should ignore factual evidence.
A justified assessment can accept that some moral reasons are directly understood while demanding critical reflection about alleged intuitions. This is stronger than both 'everyone knows, so no argument is needed' and 'people disagree, so no one knows'. Intuitionism accounts for basic moral confidence well; disagreement and the mechanism of knowledge determine how far that confidence is warranted.