John Locke was a 17th-century English philosopher known for his influential ideas on government and human rights. He argued that individuals have natural rights to life, liberty, and property, which should be protected by the state. His work laid the foundation for modern democracy and the concept of social contracts. Locke's theories were pivotal during the Enlightenment and inspired many political thinkers, including Thomas Jefferson. His writings, particularly "Two Treatises of Government," emphasized the importance of consent in governance and the right of people to revolt against unjust rulers, shaping the principles of modern political thought.