Polemic (/pəˈlɛmɪk/ pə-LEHM-ick, US also /-ˈlimɪk/ -LEEM-ick) is contentious rhetoric intended to support a specific position by forthright claims and to undermine the opposing position. The practice of such argumentation is called polemics, which are seen in arguments on controversial topics. A person who writes polemics, or speaks polemically, is called a polemicist. The word derives from Ancient Greek πολεμικός (polemikos) 'warlike, hostile', from πόλεμος (polemos) 'war'.
Polemics often concern questions in religion or politics. A polemical style of writing was common in Ancient Greece, as in the writings of the historian Polybius. Polemic again became common in medieval and early modern times. Since then, famous polemicists have included satirist Jonathan Swift, Italian physicist and mathematician Galileo, French theologian Jean Calvin, French Enlightenment writer, historian, and philosopher Voltaire, Russian author Leo Tolstoy, socialist philosophers Karl Marx and Friedrich Engels, novelist George Orwell, playwright George Bernard Shaw, communist revolutionary Vladimir Lenin, linguist Noam Chomsky, social critics H. L. Mencken, Christopher Hitchens and Peter Hitchens, and existential philosophers Søren Kierkegaard and Friedrich Nietzsche.