The big picture: By 1600, most of Europe still believed kings ruled by divine right and the Church held the final word on truth.
By 1750, a growing number of writers were arguing something radical: that reason, not tradition or faith, should be the test of every belief and every law. That shift is the Enlightenment — and it did not appear from nowhere.
This section asks a Paper 3 exam favourite: why here, why then? You need four strands of causation — intellectual, political, religious, and individual — because the essay question will often ask you to weigh which mattered most.
1. Intellectual influences
Enlightenment thinkers did not invent reason from scratch. They inherited three older traditions and repurposed them.
- Ancient ideas — Greek and Roman writers like Aristotle and Cicero had already argued that reason, not myth, could explain nature and guide good government. Enlightenment writers revived and updated this classical faith in rational enquiry.
- The Renaissance (c.1350–1600) — this earlier movement had already shifted focus from God to human potential (humanism), and it rediscovered classical texts that Enlightenment thinkers later built on.
- The Scientific Revolution (c.1550–1700) — the single most direct influence. Copernicus, Galileo and Newton showed that careful observation and mathematics — not ancient authority — could uncover the true laws of nature.
Newton's ripple effect: Isaac Newton's Principia Mathematica (1687) proved that a handful of mathematical laws explained everything from falling apples to planetary orbits.
If reason could crack the code of the universe, philosophers reasoned, why not use the same method to work out the best laws for society? This leap — from natural science to social science — is the direct bridge from the Scientific Revolution into the Enlightenment.
2. Political conditions
Ideas need soil to grow in. Europe's political landscape after 1648 gave critical thinking room to breathe, in a few different ways.
- Absolutist excess — rulers like Louis XIV of France taxed heavily, fought expensive wars, and claimed total authority. Watching this up close made writers ask what actually justified a ruler's power.
- Relative peace and stability — the Peace of Westphalia (1648) ended decades of religious war, giving intellectuals the security and leisure to debate ideas rather than just survive.
- A literate, urban elite — a growing class of merchants, lawyers and officials had the education, money and time to read, discuss and publish.
3. Religious factors — the Reformation's legacy
The Reformation mattered enormously, even though it happened a century before the Enlightenment itself.
Once Luther and Calvin successfully challenged the Catholic Church's monopoly on religious truth, they had shown — without meaning to — that a single, unquestionable authority could be defied and survive. That precedent of legitimate dissent stayed in Europe's political memory.
The decades of brutal religious war that followed (culminating in the Thirty Years' War, 1618–1648) also pushed many thinkers toward religious toleration and away from letting any single church dictate the truth for everyone.
4. Role of individuals
Structural causes only go so far — specific writers gave the movement its arguments and its name.
| Thinker | Core idea |
|---|---|
| John Locke (1632–1704) | Government exists by a social contract with the people; rulers who break it can be resisted |
| Voltaire (1694–1778) | Relentless attack on Church intolerance and censorship; championed free speech |
| Montesquieu (1689–1755) | Power should be split into branches (separation of powers) to prevent tyranny |
| Rousseau (1712–1778) | Legitimate government must express the general will of the people, not a monarch's whim |
Weighing the causes: A 'to what extent' essay on emergence wants you to rank these four strands, not just list them. A strong argument: the Scientific Revolution provided the method (reason + evidence), but it was political and religious conditions that made society ready to apply that method to government and faith — and individuals who turned it into a movement.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it free for 7 days:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Enlightenment ideas did not float in a vacuum — they spread through a Europe that was itself transforming economically, socially and technologically. This section covers the four 'developments during the era' bullet points, which the exam treats as effects that also fed back into causing more Enlightenment thought.
Economic change
The 18th century saw the slow rise of mercantilism give way to new economic thinking.
- Growth of trade and colonial commerce — overseas empires (sugar, tobacco, textiles) pumped new wealth into European ports like Bordeaux, Liverpool and Amsterdam.
- Rise of banking and credit — institutions like the Bank of England (1694) made large-scale lending and investment possible, fuelling both trade and government spending.
- Early critiques of mercantilism — Adam Smith's The Wealth of Nations (1776) argued that free markets, not state control of trade, generated the most wealth — itself an Enlightenment-style application of reason to economics.
Social change and the growth of cities
Europe's population grew significantly across the 18th century, and more of that growth clustered in towns and cities than ever before.
Why cities mattered to the Enlightenment: Cities like Paris, London and Amsterdam produced the physical spaces where new ideas actually spread: coffee houses, salons, printing shops and universities.
A growing, literate middle class (bourgeoisie) of merchants, lawyers and professionals had both the means and the appetite to buy books, attend lectures, and debate politics — they became the Enlightenment's core audience.
Scientific and technological developments
The 18th century kept building on the Scientific Revolution's momentum, with practical results people could see.
- The spread of scientific institutions — the Royal Society (London) and the Academy of Sciences (Paris) gave scientists a formal, public stage to test and share findings.
- Practical inventions — improvements like better clocks, instruments, and eventually the first steam engines (Newcomen's 1712 engine) showed reason producing real, useful results.
- Popularization of science — public lectures and illustrated encyclopedias (notably Diderot and d'Alembert's Encyclopédie, from 1751) spread scientific and Enlightenment ideas to a much wider audience than ever before.
Changes in agriculture
Less glamorous than salons and science, but just as important: farming itself was being transformed.
- New crop rotation methods — techniques such as the Norfolk four-course rotation (turnips, barley, clover, wheat) kept soil fertile without leaving fields empty (fallow) every few years.
- Enclosure of land — in Britain especially, shared common land was fenced off into private farms, boosting output but displacing many small farmers.
- Rising food supply — these changes fed the growing urban population described above, freeing up more people to work in trade, crafts and eventually early industry rather than subsistence farming.
The feedback loop: Don't treat these four changes as a random list — they connect. Agricultural improvement fed a growing population that moved into cities, where trade and economic growth created a literate middle class with time to read the new science and debate the Enlightenment's political ideas. Cause and consequence run in both directions here.
Memorize terms 3x faster
Smart flashcards show you cards right before you forget them. Perfect for definitions and key concepts.
Paper 3 essays ask you to evaluate a claim, not just recite facts. This micro's classic claim: 'The Enlightenment was primarily a product of the Scientific Revolution.' Below are the strongest arguments on each side.
Argument: Science was the main driver
- Newton's laws gave Europe a working proof that reason + evidence could uncover universal truths
- Enlightenment thinkers directly copied scientific method — observe, reason, test — and applied it to government, ethics and religion
- Key figures (Locke, Voltaire) explicitly cite Newton as their model for how to think
Argument: Other factors were just as important
- Political frustration with absolutist excess (Louis XIV's wars and taxes) gave the ideas urgency and an audience
- The Reformation had already normalized challenging a single unquestionable authority a century earlier
- Without cities, print culture and a literate middle class, scientific ideas would have stayed confined to a small elite
A stronger, more nuanced position: The strongest Paper 3 answers avoid picking just one cause. A good judgement: the Scientific Revolution supplied the method (reason tested against evidence), but it was political grievance, religious precedent, and social change that supplied the motive and the means to spread it. Method without an audience stays in a laboratory; audience without a method stays a riot. The Enlightenment needed both.
A second live debate concerns who the Enlightenment actually reached. This matters for 'significance' as a concept.
- The optimistic view — printing, salons, and encyclopedias spread new ideas widely, reaching a genuinely broad urban middle class across Europe.
- The skeptical view — Enlightenment debate mostly stayed confined to educated elites in a handful of major cities; most Europeans, especially rural peasants, were untouched by it and continued in traditional religious and social life.
- A balanced view — reach varied hugely by region: it was strongest in Paris, London and a handful of German and Italian cities, and much weaker in rural Eastern and Southern Europe.
Common essay mistake: Do not write the Enlightenment as an inevitable, unstoppable march of progress. IB examiners reward answers that show it was contested, uneven, and driven by specific, arguable causes — not a natural next step in history. Always argue why one cause mattered more, using evidence, rather than just asserting that it did.
Using the four concepts here: Cause & consequence: rank intellectual/political/religious/individual causes. Continuity & change: the Reformation's precedent of dissent is continuity feeding into Enlightenment change. Perspectives: elite Parisian salon-goers vs. rural peasants experienced this era very differently. Significance: was this the birth of modern political thought, or a narrow elite conversation? All four appear in top-band Paper 3 answers.