The primary features of the Enlightenment, which shaped modern political thought, included the emphasis on reason, individualism, and the belief in progress. Thinkers like John Locke, Voltaire, and Jean-Jacques Rousseau challenged traditional authority, advocating for the rights of individuals and the social contract. These ideas influenced revolutions, particularly in America and France, promoting democratic principles and the idea that governments should reflect the will of the people. The Enlightenment laid the groundwork for modern democratic societies.