John Locke (1632-1704) was an English philosopher and political theorist who is often considered the "father of liberalism." He argued that humans are born with a "tabula rasa" or blank slate, emphasizing the role of experience in shaping knowledge. Locke championed the ideas of natural rights, social contract, and the consent of the governed as foundations for legitimate government. He also contributed to the development of empiricism, opposing Descartes' rationalism. Locke's ideas had a profound impact on the Enlightenment, the American Revolution, and the formation of modern democratic principles.