The Enlightenment - also called the Age of Reason - was an intellectual and philosophical movement that flourished primarily in Europe and the Atlantic world during the 17th and 18th centuries, roughly spanning the period from the mid-1600s to the early 1800s. It is characterized by an emphasis on reason, individual liberty, skepticism of traditional authority (particularly ecclesiastical and monarchical), natural rights, empirical inquiry, and the belief that human progress is achievable through rational thought and education. The movement gave rise to foundational ideas in modern liberal democracy, science, economics, and political philosophy, and its principles are embedded in documents such as the United States Declaration of Independence, the French Declaration of the Rights of Man and of the Citizen, and many subsequent constitutional frameworks.
The Enlightenment emerged from earlier intellectual developments including the Scientific Revolution, the Renaissance, and the Protestant Reformation, each of which contributed to eroding the monopoly of the Catholic Church and hereditary aristocracy over knowledge and legitimacy. Key precursors include Francis Bacon's empiricism, René Descartes' rationalism, and Isaac Newton's demonstration that the natural world operates according to discoverable, universal laws. These developments encouraged thinkers to apply similar methods to questions of morality, governance, and society. The movement was not uniform; historians distinguish between national variants - the Scottish Enlightenment (Hume, Smith, Ferguson), the French philosophes (Voltaire, Rousseau, Diderot), the German Aufklärung (Kant, Lessing), the English tradition (Locke, Newton), and the American Enlightenment (Franklin, Jefferson, Madison) - each with distinct emphases and conclusions.
Several ideas recur across Enlightenment thought, though thinkers often disagreed sharply about their implications:
A full account of the Enlightenment's origins, major figures, national variations, and reception falls outside the scope of this article. See Enlightenment - History for a detailed treatment.
The Enlightenment is the subject of substantial historical and philosophical debate. Some scholars argue it was a unified project with coherent commitments to rationalism and liberalism; others hold that it was a loose family of overlapping and often contradictory tendencies. Postcolonial and critical theorists argue that Enlightenment universalism is said to have masked Eurocentric assumptions and provided ideological cover for colonialism and racial hierarchy - a position contested by those who argue the movement's principles are self-undermining of such hierarchies. Some religious thinkers argue the Enlightenment's secularism produced a moral vacuum that has weakened Western civilization, while secular critics hold it did not go far enough. The relationship between the Enlightenment and later revolutionary violence - especially the French Revolution's Reign of Terror - remains debated, with some attributing the Terror partly to Enlightenment rationalism and others arguing it represented a betrayal of core Enlightenment commitments. See Enlightenment - Debate for a structured treatment of these disagreements.
There is broad scholarly consensus that the Enlightenment was a historically significant intellectual movement that shaped modern liberal, democratic, and scientific institutions. Historians disagree about its precise boundaries, internal coherence, and normative legacy. Consensus status: not yet established.