IB Philosophy 4.2.2 Foundations for Moral Judgements Key Definitions

Immanuel Kant's categorical imperative is the supreme principle of morality, commanding unconditionally. Its first formulation requires acting only on maxims that could be willed as universal laws, and its second formulation requires treating persons always as ends in themselves, never merely as means.

Cognitivism holds that moral judgements express beliefs that are truth-apt (capable of being true or false), while non-cognitivism holds that moral judgements express attitudes, emotions, or prescriptions rather than truth-apt propositions.

Foundations for moral judgements are the sources of justification proposed for moral claims, including rationality, emotion, natural law, and environment. The foundation accepted determines whether moral judgements are universal or culturally relative, objective or subjective.

Intuitionism in moral philosophy holds that basic moral truths are self-evident and can be apprehended directly through a faculty of moral intuition, without the need for empirical evidence or deductive proof. Developed by W.D. Ross and G.E. Moore, the view grounds ethics in irreducible moral perceptions but faces the challenge of explaining persistent moral disagreement if such truths are supposedly obvious.

The naturalistic fallacy is G.E. Moore's term for the error of defining the property of goodness in terms of any natural property such as pleasure, evolutionary fitness, or social approval. Moore argued that for any proposed natural equivalent of "good" one can always meaningfully ask whether that property really is good, suggesting that moral goodness is a simple, unanalysable quality irreducible to empirical description.