Simon the jester

John Locke (1632–1704) trained as a physician at Oxford and became adviser to the Earl of Shaftesbury, a leading opponent of the king. Suspected of plotting, he fled to the Netherlands in 1683 and returned only after the Revolution of 1688, when he published the works that made him famous.

His Essay Concerning Human Understanding argued that the mind begins as a blank slate filled by experience, and his Two Treatises of Government defended natural rights to life, liberty and property and government by consent. His Letter Concerning Toleration argued for religious freedom. His ideas shaped the American Declaration of Independence and modern liberal thought.