The main impact of the Enlightenment on modern democracies was the promotion of ideas regarding individual rights, governance based on reason, and the concept of social contracts. Enlightenment thinkers, such as John Locke and Jean-Jacques Rousseau, challenged traditional authority and advocated for principles of liberty, equality, and justice. These ideas laid the philosophical foundation for democratic systems of government, emphasizing the need for consent of the governed and protection of personal freedoms. The Enlightenment significantly influenced revolutions, including the American and French Revolutions, shaping the development of democratic ideals worldwide.