The Enlightenment was an intellectual movement that dominated Europe in the 17th and 18th centuries. It promoted reason, science and individualism over tradition. Key figures included Galileo, who proved the sun was the center of the universe, challenging the church; Johannes Kepler, who discovered laws of planetary motion; and Isaac Newton, who formulated laws of gravity and motion. Philosophers like John Locke and Jean-Jacques Rousseau advocated ideas of natural rights and social contracts between rulers and citizens. Voltaire promoted tolerance and free speech. Monarchs like Frederick the Great and Maria Theresa enacted reforms, and Catherine the Great expanded education in Russia.

1. THE ENLIGHTENMENT THE AGE OF REASONS