4.3 The Enlightenment

Reason Applied to Society

The Enlightenment built on the Scientific Revolution's use of reason and empiricism, applying them to government, society, and human nature. Thinkers argued natural laws governed human affairs just as they governed physics, and that critical reasoning could improve institutions, challenge tradition, and expand human happiness and freedom.

Key Political Philosophers

John Locke argued people have natural rights (life, liberty, property) and governments derive authority from the consent of the governed, justifying revolution against tyranny. Montesquieu advocated separation of powers to prevent tyranny. Rousseau proposed the social contract and the general will as the basis of legitimate government.

Spreading Enlightenment Ideas

Voltaire championed free speech and religious toleration while criticizing the Church. Salons, coffeehouses, and printed works like Diderot's Encyclopédie spread ideas among the educated public. Adam Smith applied reason to economics, advocating free markets. Enlightened absolutists (Frederick II, Catherine the Great, Joseph II) applied reforms while retaining power.

Key terms

John Locke

Argued for natural rights (life, liberty, property) and government legitimacy based on consent of the governed.

Montesquieu

Advocated separation of powers among branches of government to prevent tyranny.

Rousseau's Social Contract

Theory that legitimate government arises from an agreement among people to follow the 'general will' for the common good.

Voltaire

Enlightenment writer who championed free speech, religious toleration, and criticized the Catholic Church.

Enlightened Absolutism

Monarchs like Frederick the Great and Catherine the Great who enacted Enlightenment-based reforms while keeping centralized power.

Try an AP-style question

Voltaire campaigned especially for…

1. absolute monarchy and censorship
2. a return to feudalism
3. religious toleration and free speech
4. state-run churches