J. L. Mackie

John Leslie Mackie (1917–1981) was an Australian analytic philosopher who held chairs at Otago, Sydney, York, and finally University College, Oxford, where he became a Fellow of the British Academy. Trained at Sydney under John Anderson and at Oriel College, Oxford, Mackie worked across metaethics, philosophy of mind, logic, and philosophy of religion. He is best known for his metaethical 'error theory' in Ethics: Inventing Right and Wrong (1977), which argued that moral discourse presupposes objective values that do not exist. In philosophy of religion, his 1955 article 'Evil and Omnipotence' revived the logical problem of evil, arguing that the existence of an omnipotent, wholly good God is logically incompatible with evil—an argument later challenged by Alvin Plantinga's free-will defense. His posthumous The Miracle of Theism (1982) offered a systematic critique of theistic arguments, surveying ontological, cosmological, design, moral, and experiential arguments and concluding that theism is irrational. Mackie also defended a Humean skepticism about miracles and rejected divine-command metaethics. His work remains a principal foil for analytic philosophers of religion including Plantinga, Richard Swinburne, and William Lane Craig, who responded to his treatment of cosmological and moral arguments. Critics charge that his logical problem of evil underestimates free-will defenses and that error theory faces self-refutation worries.