Scientific, Philosophical & Political Developments: every key term you need (+ practice quiz)
61 flashcard terms for AP European History Unit 4, written to match the course framework. Study them here, then drill them as interactive flashcards, or test yourself with the 25-question quiz — free, no account needed.
The transformation of European thought (roughly 1543–1687) from reliance on ancient authorities and theology to explanation of nature through observation, experiment, and mathematics — from Copernicus's heliocentrism to Newton's physics.
Nicolaus Copernicus (1473–1543)
Polish astronomer whose On the Revolutions of the Heavenly Spheres (1543) proposed that the Earth orbits the sun — the heliocentric theory that challenged both Ptolemaic astronomy and the Church-endorsed view of a central, stationary Earth.
Geocentric vs. Heliocentric
The geocentric (Ptolemaic) model placed Earth at the universe's center, harmonizing with Aristotle and Scripture. The heliocentric (Copernican) model placed the sun at the center — demoting Earth to one planet among several.
Tycho Brahe (1546–1601)
Danish astronomer who compiled the most precise naked-eye astronomical observations ever made. His data — inherited by his assistant Kepler — provided the empirical foundation for the new astronomy.
Johannes Kepler (1571–1630)
German astronomer who used Brahe's data to formulate three laws of planetary motion — showing planets move in ellipses, not perfect circles — replacing ancient assumptions with mathematical description.
Galileo Galilei (1564–1642)
Italian scientist who turned the telescope on the heavens — discovering Jupiter's moons, lunar mountains, and sunspots — and pioneered experimental physics. His advocacy of Copernicanism led to trial by the Roman Inquisition (1633) and house arrest.
Galileo's Trial (1633)
The Inquisition forced Galileo to recant heliocentrism and banned his Dialogue Concerning the Two Chief World Systems. The trial became the emblematic clash between the new science and religious authority.
Isaac Newton (1642–1727)
English scientist whose Principia Mathematica (1687) unified terrestrial and celestial physics through the law of universal gravitation and three laws of motion — the Scientific Revolution's crowning synthesis.
Principia Mathematica (1687)
Newton's masterwork demonstrating that one set of mathematical laws — gravity and motion — governs both falling apples and orbiting planets. It made the universe appear an ordered, knowable machine.
Francis Bacon (1561–1626)
English philosopher who championed empiricism and inductive reasoning — building knowledge from systematic observation and experiment rather than deduction from ancient authorities. Prophet of science as useful power: 'knowledge is power.'
René Descartes (1596–1650)
French philosopher who championed rationalism and deductive reasoning — doubting everything until reaching the bedrock certainty 'Cogito, ergo sum' (I think, therefore I am). He described a mechanical universe of matter in motion, knowable through mathematics.
Empiricism vs. Rationalism
Two paths to knowledge in the Scientific Revolution: empiricism (Bacon) builds truth upward from observation and experiment; rationalism (Descartes) deduces truth downward from self-evident first principles through logic and mathematics. Modern science fused both.
Scientific Method
The systematic procedure combining observation, hypothesis, experiment, and mathematical analysis — replacing appeals to Aristotle, Galen, and Scripture as the test of truth about nature.
Andreas Vesalius (1514–1564)
Flemish anatomist whose On the Fabric of the Human Body (1543), based on dissection, corrected centuries of errors inherited from the ancient physician Galen — founding modern anatomy.
William Harvey (1578–1657)
English physician who demonstrated that the heart pumps blood in continuous circulation through the body — overturning Galen's physiology through experiment and measurement.
Robert Boyle (1627–1691)
Anglo-Irish scientist considered a founder of modern chemistry. Boyle's Law described gas behavior, and his experimental program helped separate chemistry from alchemy.
Royal Society (1660)
England's premier scientific institution, chartered by Charles II — with the motto 'Nullius in verba' (take nobody's word for it). Scientific academies institutionalized research, publication, and peer communication.
French Academy of Sciences (1666)
Colbert's state-sponsored scientific academy — showing that absolutist governments also patronized science for prestige and practical benefits (navigation, engineering, warfare).
Natural Philosophy to Natural Science
The era's thinkers called their work 'natural philosophy.' Over the 17th–18th centuries it professionalized into 'science' — a distinct enterprise with its own methods, institutions, and authority.
The Enlightenment
The 18th-century intellectual movement applying reason, criticism, and the scientific spirit to society — religion, government, law, economics — confident that rational reform could produce progress and happiness. Centered in France; the philosophes were its voice.
Philosophes
The Enlightenment's public intellectuals — Voltaire, Montesquieu, Rousseau, Diderot — not academic philosophers but writers, critics, and reformers who popularized reason and attacked superstition, intolerance, and arbitrary power.
Voltaire (1694–1778)
The Enlightenment's most famous writer — master of satire (Candide) and tireless crusader against religious fanaticism and injustice ('Écrasez l'infâme' — crush the infamous thing). He championed toleration, free speech, and deism while admiring English liberty.
Montesquieu — The Spirit of the Laws (1748)
French noble who analyzed governments comparatively and argued that liberty is best preserved by separation of powers — legislative, executive, judicial — checking one another. Directly influenced the U.S. Constitution.
Jean-Jacques Rousseau (1712–1778)
Genevan philosopher who argued civilization corrupts natural goodness. The Social Contract (1762) proposed that legitimate government rests on the general will of the sovereign people — 'Man is born free, and everywhere he is in chains.'
The General Will
Rousseau's concept of the common good willed by the community as a whole — the basis of legitimate law. Inspiring to democrats, it was later invoked by revolutionaries (including Jacobins) to justify coercing dissenters to be 'forced to be free.'
Rousseau's Emile (1762)
Rousseau's treatise on education arguing children should learn naturally, by experience and stages of development — enormously influential on modern pedagogy, though it consigned girls (Sophie) to education for domesticity.
Denis Diderot & the Encyclopédie (1751–1772)
Diderot edited the 28-volume Encyclopédie — the Enlightenment's collective manifesto, compiling knowledge and criticism from over 100 contributors to 'change the general way of thinking.' Banned repeatedly, it spread anyway.
Adam Smith — The Wealth of Nations (1776)
Scottish economist who attacked mercantilism, arguing that individuals pursuing self-interest in free markets are led 'as if by an invisible hand' to enrich society — the founding text of economic liberalism (laissez-faire).
Invisible Hand
Smith's metaphor for how free competition channels self-interest into public benefit — producers must serve consumers to profit — making state direction of the economy largely unnecessary.
Physiocrats
French economic thinkers (Quesnay, Turgot) who held that land is the source of all wealth and that the economy follows natural laws best left alone — coining 'laissez faire, laissez passer.' Precursors of Smith.
Cesare Beccaria — On Crimes and Punishments (1764)
Italian reformer who argued punishment should be proportionate, certain, and swift — condemning torture and capital punishment as neither just nor effective. Founded modern criminology; influenced reformers from Catherine II to the U.S. founders.
Mary Wollstonecraft — A Vindication of the Rights of Woman (1792)
English writer who turned Enlightenment logic on its authors: if reason defines humanity, women possess it equally and deserve equal education and citizenship. Founding text of Western feminism.
Immanuel Kant — 'What Is Enlightenment?' (1784)
German philosopher who defined Enlightenment as 'man's emergence from his self-imposed immaturity' — daring to think for oneself: 'Sapere aude!' (Dare to know!). He synthesized rationalism and empiricism in his critical philosophy.
Deism
The 'religion of reason' held by many philosophes: a rational God created the universe and its laws — the divine watchmaker — but does not intervene through miracles, revelation, or answered prayers. Morality, not dogma, is true worship.
David Hume (1711–1776)
Scottish philosopher whose radical skepticism questioned miracles, causation, and religious belief itself — pushing empiricism to conclusions that unsettled even fellow philosophes.
Baron d'Holbach
German-French philosophe whose salon fed the movement's radical wing; his System of Nature (1770) argued openly for atheism and materialism — a step further than most Enlightenment thinkers would go publicly.
Salons
Parisian gatherings hosted by influential women — Madame Geoffrin, Madame du Deffand, Julie de Lespinasse — where philosophes, aristocrats, and foreign visitors debated ideas. Salonnières set the tone of Enlightenment sociability and protected controversial writers.
Coffeehouses
Urban gathering places — hundreds in London and Paris — where men of varied ranks read newspapers and debated politics over coffee. 'Penny universities' that helped create modern public opinion.
Republic of Letters
The transnational network of writers, scientists, and readers exchanging books, journals, and correspondence across Europe — an international community of critical discourse transcending state borders and censorship.
Public Sphere
The new social space — print, salons, coffeehouses, academies, lodges — where private individuals debated public matters and formed 'public opinion,' a tribunal even monarchs came to fear. (Concept later theorized by Habermas.)
Censorship & the Book Trade
France banned and burned Enlightenment works, but enforcement was porous: books printed in Amsterdam or Geneva were smuggled in, and censors like Malesherbes quietly protected the Encyclopédie. Persecution often boosted sales.
Freemasonry
Fraternal lodges spreading across 18th-century Europe, mixing nobles and bourgeois in rituals of equality, philanthropy, and self-improvement — a key institution of Enlightenment sociability (and of conspiracy theories about it).
Enlightened Absolutism (Review)
Monarchs — Frederick II, Catherine II, Joseph II — who adopted Enlightenment language and selected reforms (legal codes, toleration, education) while retaining absolute power. Reform from above, within strict limits.
Enlightenment & the American Revolution
American founders drew directly on Locke (natural rights, consent), Montesquieu (separation of powers), and Beccaria (criminal justice). The Declaration of Independence read as Enlightenment philosophy in action — and its success electrified European reformers.
Rococo
The early 18th-century artistic style of aristocratic pleasure — light, ornate, playful (Watteau, Boucher, Fragonard) — associated with salon culture and the French elite.
Neoclassicism
The later 18th-century artistic reaction against Rococo frivolity — order, symmetry, and moral seriousness modeled on Greece and Rome (Jacques-Louis David's Oath of the Horatii) — the visual language of Enlightenment virtue and, soon, Revolution.
Classical Music — Haydn, Mozart, Beethoven
The Viennese classical style prized clarity, balance, and form — paralleling Enlightenment aesthetics. Patronage began shifting from court and church to public concerts, with Beethoven bridging toward Romanticism.
The Novel
The 18th century's rising literary form — Richardson's Pamela, Fielding's Tom Jones, Rousseau's Julie — read by an expanding middle-class (and female) audience, cultivating sentiment, individual interiority, and shared moral imagination.
Reading Revolution
The 18th-century expansion of literacy, newspapers, journals, lending libraries, and cheap print — readers shifted from intensive rereading of a few religious texts to extensive reading of many secular ones.
Grand Tour
The educational journey through France and Italy that finished a young gentleman's education — spreading cosmopolitan taste, classical antiquities, and Enlightenment connections across European elites.
Bourgeoisie's Rise
The expanding commercial and professional middle class consumed Enlightenment print culture, filled salons and lodges, and increasingly measured society by talent and merit rather than birth — an audience whose expectations monarchy struggled to satisfy.
Jewish Emancipation Debates
Enlightenment universalism raised the question of Jewish civil rights. Moses Mendelssohn embodied the Haskalah (Jewish Enlightenment); Joseph II's Toleration Edict (1782) eased restrictions; full emancipation came first with the French Revolution.
Methodism — John Wesley (1703–1791)
An emotional religious revival within the Church of England emphasizing personal conversion and holy living — evidence that the 'Age of Reason' was also an age of heartfelt popular piety.
Pietism
A German Protestant renewal movement stressing personal devotion, Bible study, and good works over formal doctrine — like Methodism, a counterpoint to elite religious rationalism.
Skepticism & Religious Toleration
From Bayle's Dictionary (doubting persecution could ever be just) to Voltaire's Calas campaign, Enlightenment writers made religious toleration a central demand — realized partially in Prussia, Austria (1781), and revolutionary France.
Jean Calas Affair (1762)
A Protestant merchant in Toulouse executed on flimsy evidence for allegedly murdering his son to prevent conversion to Catholicism. Voltaire's campaign posthumously exonerated him — the Enlightenment's most famous crusade against fanaticism.
Émilie du Châtelet (1706–1749)
French mathematician and physicist who translated Newton's Principia into French (still the standard translation) and contributed to physics — emblem of women's participation in, and exclusion from, official science.
Women and the Enlightenment
Women hosted the salons and swelled the novel-reading public, yet most philosophes (Rousseau above all) defended domestic roles. Wollstonecraft and Olympe de Gouges exposed the contradiction between universal rights and women's exclusion.
Enlightenment Critique of Slavery
Montesquieu satirized slavery's justifications; the Encyclopédie condemned it; abolitionist societies formed in Britain and France by the 1780s. Yet many thinkers (and economies) remained entangled with it — a central Enlightenment contradiction.
Progress
Perhaps the Enlightenment's core faith: through reason, science, and reform, humanity can steadily improve its condition — an idea (Condorcet's Progress of the Human Mind) that replaced nostalgia for a golden past with confidence in the future.
Scientific Revolution → Enlightenment Link
Newton proved nature obeys discoverable rational laws; the philosophes asked why society, government, and religion shouldn't be examined the same way. The Enlightenment was the scientific method turned on human institutions.