Intuitionism - G.E. Moore and the naturalistic fallacy

Moore  criticised naturalism in his book Principia Ethica, asserting that moral judgements are based on infallible intuitive knowledge of good things - any disagreements about morality are simply about the actions that might bring about good things, rather than the good things themselves, as they are self-evident

Good is indefinable, because it is a simple idea - much like 'yellow'

• 'Yellow' cannot be described in any other way than to say it is yellow, in much the same way that 'good' cannot be described in any other way - they are simple ideas that cannot be broken down

To define an ethical judgement as a factual one is an error, as, in trying to do this, naturalists confuse the property of goodness with some other…