The ideas of political writer Thomas Paine made a considerable impact on his time. His pamphlet, "Common Sense", crystallized the arguments for independence which fuelled the American Revolution. His "Rights of Man", written in defence of the French Revolution, made him the spokesman for English radicalism against the oppressive tradition of the 18th century. This study examines Paine's life and thought, and demonstrates the continuing relevance of his theories to modern politics. Sir Alfred Ayer has written 19 books including "Language, Truth and Logic" and "Voltaire".