The Enlightenment
How a new faith in reason and evidence remade philosophy, science, and government between 1620 and 1800
Starting with Francis Bacon's case for observation over inherited authority, a network of philosophers, scientists, and writers across Britain, France, Germany, and the Netherlands built a new method for finding out what is true and a new argument for how people should be governed. This timeline follows the arc from Bacon and Descartes through Newton's physics, Locke's political theory, the French philosophes and their Encyclopedie, to Kant's 1784 definition of enlightenment itself and the documents, the American Declaration of Independence and the French Declaration of the Rights of Man, that turned the ideas into politics. Every event is drawn from the Stanford Encyclopedia of Philosophy, primary texts, and university and museum sources that were fetched and checked against the specific claim.
Source healthshow
- Primary source17 events
- Reputable source6 events
42 of 42 checked source links loaded and matched the event’s key terms. This confirms the source is live and on-topic, not that it proves the claim, which is what reading it is for.
4 sources couldn’t be checked automatically, often a legitimate source that blocks automated readers. These are left out of the figure above rather than counted against it, and are worth reading directly.
No reader corrections reviewed yet. See something wrong? Every event page has a way to say so.
Every event names its strongest source; grades come from the domain and declared type. Last reviewed . See how trust works and the source registry.
Events
- October 1620Well documented
Primary source · 2 sourceswhy?
Best source: Novum Organum
Cited as a "primary" source (no stronger domain match).Bacon Publishes the Instauratio Magna and the Novum Organum
In October 1620 Francis Bacon published the Instauratio Magna, a planned six-part project to rebuild human knowledge from scratch. Its centerpiece, the Novum Organum ("New Instrument"), attacked the method philosophers had leaned on since Aristotle: starting from general premises and reasoning downward. Bacon argued the reverse. Collect particular observations first, organize them into tables of instances, and let general rules emerge from the data, a process later generations called induction. He also cataloged the mental habits that corrupt reasoning, which he called the Idols of the Tribe, the Cave, the Marketplace, and the Theatre, covering human bias, individual quirks, the slipperiness of language, and blind deference to inherited philosophical systems.
Why it matters: Bacon gave the emerging scientific community a shared justification for experiment over authority: test claims against nature, then generalize. The Royal Society later took Bacon's program as its founding charter, and his idols of the mind anticipate modern discussions of cognitive bias in a way historians of science still cite directly.
How we know: The Instauratio Magna and Novum Organum survive in their original Latin editions and in translation; the Stanford Encyclopedia of Philosophy's entry on Bacon traces the 1620 publication and its contents from those texts.
Author: Francis Bacon · Work: Instauratio Magna / Novum Organum · Published: October 1620 · Key idea: Induction from observation, the four Idols of the mind
Sources - 1637Well documented
Primary source · 2 sourceswhy?
Best source: A Discourse on Method
Cited as a "primary" source (no stronger domain match).Descartes Publishes the Discourse on Method
In 1637 Rene Descartes published the Discourse on Method, written in French rather than scholarly Latin so an educated general reader could follow it. Descartes proposed stripping away every belief that could possibly be doubted, including the evidence of the senses, to find something certain to rebuild knowledge on. He found it in the act of doubting itself: even if he doubted everything else, the fact that he was thinking proved he existed, summarized later as "cogito, ergo sum", I think, therefore I am. From that single certainty he tried to reconstruct a foundation for science built on clear and distinct ideas rather than inherited scholastic authority.
Why it matters: The cogito made the individual thinking mind, not scripture or Aristotle, the starting point for certainty, a move historians treat as one of the hinges between medieval and modern philosophy. It set the terms for a running argument about the reliability of reason versus the senses that Locke, Hume, and Kant would each answer differently over the following century and a half.
How we know: The Discourse survives in Descartes' original French and in later editions collecting his complete works; the Stanford Encyclopedia of Philosophy's entry on Descartes traces the cogito argument to these texts and to his later Meditations.
Author: Rene Descartes · Work: Discourse on Method · Published: 1637 · Key phrase: Cogito, ergo sum (I think, therefore I am)
- 1651Well documented
Primary source · 2 sourceswhy?
Best source: Leviathan
Cited as a "primary" source (no stronger domain match).Hobbes Publishes Leviathan
Thomas Hobbes published Leviathan in 1651, during the aftermath of the English Civil War, arguing that people in a hypothetical "state of nature" without any government would be locked in a war of every man against every man, making life, in his famous phrase, solitary, poor, nasty, brutish, and short. To escape that condition, Hobbes argued, individuals rationally agree to a social contract, surrendering their private right to use force to a single sovereign authority, the Leviathan of the title, in exchange for protection and order. He treated this sovereign's authority as close to absolute, since any division of power risked collapsing back into civil war.
Why it matters: Leviathan made the state's authority a product of human agreement rather than divine right, a move that reframed political legitimacy in terms every later Enlightenment political theorist, including Locke and Rousseau, had to answer directly, usually by rejecting Hobbes's absolutism while keeping his social-contract framework.
How we know: Leviathan survives in its original 1651 English printing; the Stanford Encyclopedia of Philosophy's entry on Hobbes's moral and political philosophy dates the work and summarizes its argument from that text and Hobbes's other writings.
Author: Thomas Hobbes · Work: Leviathan · Published: 1651 · Key idea: Social contract, state of nature, absolute sovereign
- November 28, 1660Well documented
Primary source · 2 sourceswhy?
Best source: History of the Royal Society
Cited as a "primary" source (no stronger domain match).The Royal Society Is Founded in London
On November 28, 1660, a group of natural philosophers meeting at Gresham College in London, including Christopher Wren, who had just delivered a lecture as the college's Professor of Astronomy, agreed to found a society devoted to what they called improving natural knowledge. The group met weekly to watch experiments performed and repeated in front of the whole membership before a claim was accepted, and it received a royal charter from Charles II in 1662 as The Royal Society of London for Improving Natural Knowledge. Its later motto, Nullius in verba, roughly "take nobody's word for it," captured Bacon's insistence on verifying claims against demonstrated fact rather than citing authority.
Why it matters: The Royal Society became the model for scientific institutions across Europe and gave figures like Isaac Newton, whose Principia it helped publish, a forum where experimental results were checked in public before they counted as knowledge. That practice of open verification is the direct ancestor of peer review.
How we know: The Royal Society's own institutional history, drawn from its surviving meeting minutes and charter documents, records the November 1660 meeting and the 1662 charter.
Founded: November 28, 1660 · Location: Gresham College, London · Royal charter: 1662, under Charles II · Motto: Nullius in verba
Sources - 1687Well documented
Reputable source · 2 sourceswhy?
Best source: Newton's Philosophiae Naturalis Principia Mathematica
The domain "plato.stanford.edu" is on our Reputable source registry.Newton Publishes the Principia Mathematica
Isaac Newton published Philosophiae Naturalis Principia Mathematica in 1687, paid for and pushed to print by the astronomer Edmond Halley after Newton had shown Halley he could mathematically prove that an inverse-square force from the sun would produce the elliptical planetary orbits Kepler had described. The Principia laid out Newton's three laws of motion and his law of universal gravitation, showing with geometric proofs that the same force pulling an apple to the ground also holds the moon in orbit and governs the paths of comets. It replaced separate explanations for terrestrial and celestial motion with a single mathematical system.
Why it matters: The Principia became the working model of what a mature physical science looks like: a small set of laws, stated mathematically, that predict a wide range of observed phenomena. Later Enlightenment thinkers, including Voltaire, who popularized Newton's physics in France, treated Newtonian method as proof that reason applied to nature could replace inherited authority, and pushed to apply the same standard to society and government.
How we know: The Principia survives in its 1687 first edition and Newton's revised 1713 and 1726 editions; the Stanford Encyclopedia of Philosophy's entry on the work traces its publication history and content from these editions.
Author: Isaac Newton · Work: Philosophiae Naturalis Principia Mathematica · Published: 1687 · Patron: Edmond Halley funded publication
- 1689Well documented
Primary source · 2 sourceswhy?
Best source: Two Treatises of Government
Cited as a "primary" source (no stronger domain match).Locke Publishes the Two Treatises of Government
John Locke published Two Treatises of Government in 1689, shortly after England's Glorious Revolution replaced James II with William and Mary. The First Treatise refuted the theory of the divine right of kings. The Second Treatise argued instead that people in a state of nature already possess natural rights to life, liberty, and property, and that they form governments by consent specifically to protect those rights. If a government violates that trust, Locke argued, the people retain a right to resist and replace it. He also grounded property in labor: mixing one's work with unowned land or resources, he argued, makes them rightfully one's own.
Why it matters: Locke's consent-based theory of government, with its built-in justification for resisting a government that breaks the trust, became the direct philosophical source for the American Declaration of Independence's language of unalienable rights and government deriving its just powers from the consent of the governed.
How we know: The Two Treatises survive in Locke's original text; the Stanford Encyclopedia of Philosophy's entries on Locke and on his political philosophy summarize the work's arguments and 1689 publication from that text.
Author: John Locke · Work: Two Treatises of Government · Published: 1689 · Key idea: Natural rights, government by consent, right to resist tyranny
- December 1689Well documented
Primary source · 2 sourceswhy?
Best source: An Essay Concerning Humane Understanding, Volume I
Cited as a "primary" source (no stronger domain match).Locke Publishes An Essay Concerning Human Understanding
John Locke published An Essay Concerning Human Understanding in December 1689, dated 1690 on its title page. Against philosophers who argued that some ideas, like the concept of God or basic logical principles, are innate and present at birth, Locke argued the mind starts as what he called white paper, void of all characters, and that every idea we have comes either from sensation, the raw data of the outside world reaching us through our senses, or reflection, the mind's awareness of its own operations. Complex ideas, he argued, are built up by combining and comparing these simple ones. The Essay also set out to determine the limits of human knowledge, distinguishing what we can know with certainty from what we can only hold as probable belief.
Why it matters: The blank-slate argument made empiricism, the position that knowledge comes from experience rather than innate reason, the dominant framework for British philosophy through Berkeley and Hume, and it fed directly into Enlightenment arguments for education and social reform: if minds are shaped by experience rather than fixed by birth, changing a person's circumstances can change what they become.
How we know: The Essay survives in Locke's original text, revised through multiple editions in his lifetime; the Stanford Encyclopedia of Philosophy's entry on Locke summarizes its empiricist argument and December 1689 publication from that text.
Author: John Locke · Work: An Essay Concerning Human Understanding · Published: December 1689 (title page dated 1690) · Key idea: The mind as a blank slate; ideas from sensation and reflection
- 1697Well documented
Primary source · 2 sourceswhy?
Best source: The Dictionary Historical and Critical of Mr. Peter Bayle, vol. 1
Cited as a "primary" source (no stronger domain match).Bayle Publishes the Historical and Critical Dictionary
Pierre Bayle, a French Protestant who had fled to the Dutch Republic to escape Catholic persecution, published his Historical and Critical Dictionary in 1697, expanded in 1702. Structured as an encyclopedia of biographical and historical entries, the Dictionary used dense footnotes to question received claims in theology, history, and philosophy, applying skeptical scrutiny to sources that earlier scholarship had simply repeated. Bayle argued, controversially for his time, that a society of atheists could in principle be as moral as a society of believers, since moral behavior does not require religious belief to motivate it.
Why it matters: The philosopher Ernst Cassirer later called the Dictionary the "Arsenal of the Enlightenment" because so many 18th-century writers, including Voltaire and the authors of Diderot's Encyclopedie, mined it directly for arguments and citations. Inventories of private European libraries from the period show it was one of the most widely owned reference works of the century.
How we know: The Dictionary survives in its original French editions and later translations; the Stanford Encyclopedia of Philosophy's entry on Bayle traces its 1697 and 1702 publication and Cassirer's assessment from these editions and later scholarship.
Author: Pierre Bayle · Work: Historical and Critical Dictionary · Published: 1697 (expanded 1702) · Scale: About six million words
- c. 1730s onwardWell documented
Reputable source · 2 sourceswhy?
Best source: Parisian Salons & the Enlightenment
The domain "worldhistory.org" is on our Reputable source registry.The Paris Salons Become Engines of Enlightenment Debate
From the early 18th century, private gatherings called salons, hosted mainly by well-connected Parisian women, became regular venues where writers, scientists, aristocrats, and foreign visitors met to discuss philosophy, science, literature, and politics as equals. Marie Therese Rodet Geoffrin, whose salon ran for decades from the 1730s, is often credited as the inventor of the Enlightenment salon model: a hostess set the guest list, kept conversation civil and wide-ranging, and created a space where new and sometimes radical ideas could be tested aloud before they reached print. Guests crossed rank and profession in a way formal academies did not allow.
Why it matters: The salons gave Enlightenment ideas a social network for circulating and being refined through argument before publication, and they gave women like Geoffrin real, if informal, influence over which philosophers and ideas gained a hearing in a culture that barred them from universities and academies.
How we know: Contemporary letters, memoirs, and guest lists document the Paris salons and their hostesses; the World History Encyclopedia's account of the Parisian salons draws on these records.
Setting: Private drawing rooms, mainly in Paris · Notable hostess: Marie Therese Rodet Geoffrin · Active: From the 1730s through the century
- 1740-1786Well documented
Reputable source · 2 sourceswhy?
Best source: Frederick the Great: Forging the Prussian State
The domain "worldhistory.org" is on our Reputable source registry.Frederick the Great Practices Enlightened Absolutism in Prussia
Frederick II of Prussia, who ruled from 1740 to 1786, styled himself the "first servant of the state" and used Enlightenment ideas to justify administrative and legal reforms while keeping full personal control of the government, a stance historians call enlightened absolutism. He reinstated the Berlin Academy of Sciences and recruited leading European scholars to it, gave Jean-Jacques Rousseau shelter for several years when Rousseau was a fugitive after The Social Contract's condemnation, and kept up a decades-long correspondence with Voltaire, who lived at Frederick's court for a period before the two men had a bitter falling out. Frederick reformed Prussian law, expanded religious toleration, and promoted agricultural improvement, all while running one of Europe's most rigid military states.
Why it matters: Frederick's career is the clearest example of the era's central contradiction: reform-minded rulers absorbed Enlightenment arguments about efficient, rational government and religious toleration without extending them into any check on the ruler's own power, a pattern also visible in Catherine the Great's Russia.
How we know: Frederick's correspondence with Voltaire and Rousseau survives and is documented in the World History Encyclopedia's biography of Frederick, which traces his patronage of the Berlin Academy and his relationships with Enlightenment writers.
Ruler: Frederick II (Frederick the Great) of Prussia · Reign: 1740-1786 · Correspondent: Voltaire · Sheltered: Jean-Jacques Rousseau
- 1748Well documented
Reputable source · 2 sourceswhy?
Best source: Montesquieu
The domain "plato.stanford.edu" is on our Reputable source registry.Montesquieu Publishes The Spirit of the Laws
Charles-Louis de Secondat, Baron de Montesquieu, published The Spirit of the Laws in 1748 after roughly two decades of research and travel, including time in England studying its constitution. The book argued that a government's laws have to fit its climate, geography, economy, religion, and customs rather than following one universal model, but its most influential section proposed that political liberty depends on separating a state's legislative, executive, and judicial powers so that no single body holds all three. Montesquieu pointed to England's division between Parliament, the crown, and the courts as an example, though historians note he read English practice somewhat more neatly than it actually operated.
Why it matters: The separation-of-powers argument directly shaped the framers of the United States Constitution, who split the federal government into three branches with checks on each other, and it remains the standard justification for constitutional structures that divide power across institutions rather than concentrating it in one ruler or body.
How we know: The Spirit of the Laws survives in Montesquieu's original French text and contemporary translations; the Stanford Encyclopedia of Philosophy's entry on Montesquieu dates the 1748 publication and traces the separation-of-powers argument to it.
Author: Montesquieu (Charles-Louis de Secondat) · Work: The Spirit of the Laws · Published: 1748 · Key idea: Separation of legislative, executive, and judicial power
Sources- Stanford Encyclopedia of Philosophy. Montesquieu · reference
- World History Encyclopedia. Montesquieu · reference
- 1748Well documented
Primary source · 2 sourceswhy?
Best source: An Enquiry Concerning Human Understanding
Cited as a "primary" source (no stronger domain match).Hume Argues Reason Cannot Prove Cause and Effect
David Hume laid out his mature empiricism in An Enquiry Concerning Human Understanding, published in 1748 as a more accessible reworking of his earlier Treatise of Human Nature. Hume divided everything the mind can consider into relations of ideas, truths like mathematics that hold by definition, and matters of fact, claims about the world that depend on experience. He argued that our belief in cause and effect, that fire causes heat or bread nourishes, rests entirely on habit built from repeated observation, not on any logical necessity we can perceive or prove. We never actually observe one event forcing another to happen; we only observe one event followed by another, over and over, until we expect the pattern to continue.
Why it matters: Hume's argument meant that even science's basic assumption, that the future will resemble the past, cannot be proven by reason alone. Immanuel Kant later said reading Hume woke him from his "dogmatic slumber" and pushed him to write the Critique of Pure Reason to answer the challenge.
How we know: The Enquiry survives in Hume's original text; the Stanford Encyclopedia of Philosophy's entry on Hume traces his account of impressions, ideas, and causation to it and to the Treatise.
Author: David Hume · Work: An Enquiry Concerning Human Understanding · Published: 1748 · Key idea: Causation as habit, not logical necessity
- 1751-1772Well documented
Primary source · 2 sourceswhy?
Best source: The ARTFL Encyclopedie Project
Cited as a "primary" source (no stronger domain match).Diderot and d'Alembert Begin Publishing the Encyclopedie
Denis Diderot and Jean le Rond d'Alembert began publishing the Encyclopedie, ou Dictionnaire raisonne des sciences, des arts et des metiers, in 1751, eventually running to 17 volumes of text and 11 volumes of plates by 1772, with 74,000 articles from more than 130 contributors including Voltaire, Rousseau, and Montesquieu. Beyond compiling existing knowledge, the editors used cross-references between articles, a technique they called renvois, to let readers connect an orthodox religious entry to a more skeptical scientific one and draw their own conclusions, without the editors having to state a forbidden argument outright. Diderot also insisted on detailed articles and plates documenting the mechanical arts and trades, treating a locksmith's or a weaver's practical knowledge as worth the same systematic attention as classical philosophy.
Why it matters: French royal authorities suspended the Encyclopedie's publishing privilege more than once over its implicit challenges to church and crown, but it kept being produced and sold across Europe anyway, making it a working demonstration that Enlightenment ideas about method, tolerance, and evidence could circulate widely even under censorship.
How we know: The Encyclopedie's original volumes are digitized and searchable through the University of Chicago's ARTFL Encyclopedie project, which documents its 1751 to 1772 publication run and contributor list from the original text.
Editors: Denis Diderot and Jean le Rond d'Alembert · Published: 1751-1772 · Scale: 17 volumes of text, 11 volumes of plates, 74,000 articles · Contributors: 130+, including Voltaire, Rousseau, Montesquieu
- 1758Well documented
Reputable source · 2 sourceswhy?
Best source: Economics in Early Modern Philosophy
The domain "plato.stanford.edu" is on our Reputable source registry.The Physiocrats Argue Land Is the Only Source of Wealth
Francois Quesnay, court physician to Louis XV at Versailles, published his Tableau economique in 1758, a diagrammatic model tracing how income flows between landowners, farmers, and merchants through a national economy. Quesnay and the school of thinkers who gathered around him, known as the physiocrats, argued that agriculture was the only truly productive source of new wealth and that governments should stop interfering with markets through tariffs and controls, a policy stance summarized in the phrase laissez-faire, laissez-passer. Quesnay's follower Pierre Samuel du Pont de Nemours promoted physiocracy in a 1768 treatise as a new science standing alongside the natural sciences, and the physiocrat sympathizer Anne-Robert-Jacques Turgot briefly served as Louis XVI's controller general in the 1770s before opposition to his reforms drove him from office.
Why it matters: The physiocrats were the first group to try modeling a national economy as an interconnected system rather than a collection of separate transactions, and their argument against government interference in markets became one of the direct influences Adam Smith engaged with, and partly rejected, when he wrote The Wealth of Nations.
How we know: Quesnay's Tableau economique and the physiocrats' writings survive in their original editions; the Stanford Encyclopedia of Philosophy's entry on economics in early modern philosophy traces the Tableau's 1758 publication and the school's later history from these texts.
Founder: Francois Quesnay · Work: Tableau economique · Published: 1758 · Key idea: Land as the source of wealth; laissez-faire
- 1762-1796Well documented
Primary source · 2 sourceswhy?
Best source: Treasures of Catherine the Great in the Hermitage Rooms
Cited as a "primary" source (no stronger domain match).Catherine the Great Corresponds with the Philosophes
Catherine II of Russia, who came to power in 1762 and ruled until 1796, cultivated relationships with leading French philosophes as part of her self-image as an enlightened ruler. She was praised by Voltaire and corresponded with him for years, and she supported Denis Diderot financially, buying his personal library in 1765 while letting him keep and use the books for the rest of his life, and later hosted him at her court in St. Petersburg. Catherine founded the Hermitage Museum, which grew from her private art collection and remains one of the largest art museums in the world, and she attempted, with limited practical success, legal and administrative reforms informed by Enlightenment ideas about rational government.
Why it matters: Catherine's patronage of Diderot and Voltaire gave the French Enlightenment an audience and financial backing at the Russian court, but her actual governance, including the expansion of serfdom during her reign, shows the same gap between enlightened rhetoric and unchanged autocratic power visible in Frederick the Great's Prussia.
How we know: Catherine's correspondence and patronage of Diderot and Voltaire, and her founding of the Hermitage, are documented in the World History Encyclopedia's biography of Catherine the Great.
Ruler: Catherine II (Catherine the Great) of Russia · Reign: 1762-1796 · Patronage: Denis Diderot's library; correspondence with Voltaire · Founded: The Hermitage Museum
- 1762Well documented
Reputable source · 2 sourceswhy?
Best source: Voltaire
The domain "worldhistory.org" is on our Reputable source registry.Voltaire Takes Up the Case of Jean Calas
In 1762 the Protestant merchant Jean Calas was tortured and executed in Toulouse after being wrongly convicted of murdering his own son to prevent a conversion to Catholicism, when the son had in fact died by suicide. Voltaire, then living near the Swiss border at Ferney, investigated the case, publicized it across Europe, and took up two similar miscarriages of justice, the Chevalier de la Barre and the Sirven family, framing all three as products of Catholic religious intolerance. He turned his advocacy into the 1763 Treatise on Tolerance, arguing that no single citizen's reason should be forced to submit to another's religious authority, and campaigned until the Calas verdict was formally overturned.
Why it matters: The Calas affair gave Voltaire's argument for tolerance a concrete victim instead of an abstract principle, and the eventual reversal of the conviction became one of the Enlightenment's clearest demonstrations that public argument and organized pressure could overturn a state's own judicial verdict.
How we know: Voltaire's Treatise on Tolerance survives in its original French text and translations; the World History Encyclopedia's account of Voltaire's life documents the Calas, La Barre, and Sirven cases and quotes his own writing on tolerance.
Victim: Jean Calas, executed 1762 · Advocate: Voltaire · Resulting work: Treatise on Tolerance (1763) · Location: Toulouse, France
Sources- World History Encyclopedia. Voltaire · reference
- Stanford Encyclopedia of Philosophy. Voltaire · reference
- 1764Well documented
Primary source · 2 sourceswhy?
Best source: On Crimes and Punishments
Cited as a "primary" source (no stronger domain match).Beccaria Publishes On Crimes and Punishments
Cesare Beccaria, a young Milanese jurist, published On Crimes and Punishments anonymously in 1764. He argued that the sole legitimate purpose of criminal punishment is deterrence, preventing the same person and others from offending again, not vengeance or the infliction of suffering for its own sake. On that basis he denounced judicial torture, secret accusations, and the death penalty as excessive and counterproductive, and called for punishments to be proportionate to the crime and applied swiftly and consistently, arguing that certainty and promptness of punishment deterred crime more effectively than severity. The book was translated across Europe within a few years and read by reform-minded rulers as a practical blueprint.
Why it matters: On Crimes and Punishments became the founding text of modern penology and directly influenced legal reforms in several European states and, later, the framers of American criminal law protections against cruel and excessive punishment.
How we know: The book survives in its original Italian and in period translations; the National Constitution Center's document library, which reproduces and summarizes the text, quotes Beccaria's argument that punishment exists only to prevent future offenses.
Author: Cesare Beccaria · Work: On Crimes and Punishments · Published: 1764, Livorno (anonymously) · Key idea: Punishment as deterrence, opposition to torture and the death penalty
- March 9, 1776Well documented
Primary source · 2 sourceswhy?
Best source: An Inquiry into the Nature and Causes of the Wealth of Nations, Book IV
Cited as a "primary" source (no stronger domain match).Adam Smith Publishes The Wealth of Nations
Adam Smith published An Inquiry into the Nature and Causes of the Wealth of Nations in March 1776. Smith opened by describing a pin factory where breaking production into separate specialized steps, one worker drawing the wire, another cutting it, another sharpening the point, let a small team produce many times more pins per day than the same workers could individually, illustrating what he called the division of labor as the main engine of increased productivity. He argued that an individual pursuing only their own gain in a competitive market is, in his words, "led by an invisible hand to promote an end which was no part of his intention," often benefiting society more effectively than someone who deliberately sets out to serve the public good, and he argued against government-granted monopolies and trade restrictions that protected established interests over open competition.
Why it matters: The Wealth of Nations gave classical economics its founding text and its central image, self-interest channeled by competition into public benefit, that later economists and policymakers have argued over ever since, including how far Smith himself meant the invisible-hand passage as a general rule rather than one specific observation about domestic versus foreign investment.
How we know: The Wealth of Nations survives in Smith's original text; the Stanford Encyclopedia of Philosophy's entry on Smith's moral and political philosophy dates its 1776 publication, and the Library of Economics and Liberty's online edition of Book IV preserves the invisible-hand passage in context.
Author: Adam Smith · Work: An Inquiry into the Nature and Causes of the Wealth of Nations · Published: March 9, 1776 · Key idea: Division of labor; the invisible hand of market competition
- July 4, 1776Well documented
Primary source · 2 sourceswhy?
Best source: Declaration of Independence: A Transcription
Cited as a "primary" source (no stronger domain match).The American Declaration of Independence Puts Locke's Theory into Practice
The Second Continental Congress adopted the Declaration of Independence on July 4, 1776, drafted principally by Thomas Jefferson. The document opens by asserting that all men are created equal and endowed with unalienable rights to life, liberty, and the pursuit of happiness, and that governments are instituted to secure those rights, deriving their just powers from the consent of the governed. That structure, natural rights preceding government, government legitimate only by consent, and a people's right to alter or abolish a government that becomes destructive of those ends, follows Locke's Two Treatises of Government closely enough that historians treat the Declaration as Locke's political theory converted directly into a founding political act.
Why it matters: The Declaration turned Enlightenment political theory from an academic argument into the founding legal claim of a new nation, and its language of self-evident natural rights became a template invoked by later reform and independence movements far beyond the United States, including the French Declaration of the Rights of Man thirteen years later.
How we know: The Declaration's original engrossed manuscript is held by the National Archives, which publishes an authoritative transcript of its text.
Adopted: July 4, 1776 · Principal author: Thomas Jefferson · Body: Second Continental Congress · Key phrase: Life, liberty, and the pursuit of happiness
- 1784Well documented
Primary source · 2 sourceswhy?
Best source: What Is Enlightenment?
Cited as a "primary" source (no stronger domain match).Kant Answers the Question "What Is Enlightenment?"
Immanuel Kant published his short essay An Answer to the Question: What Is Enlightenment? in 1784, responding to a public debate already underway in Berlin's periodicals. Kant defined enlightenment as humanity's emergence from a self-imposed immaturity, meaning the inability to use one's own understanding without being directed by someone else, whether a pastor, a doctor, or a book. He located the cause of that immaturity not in a lack of intelligence but in a lack of resolve and courage, and gave the essay its motto, Sapere aude, "dare to know," have the courage to use your own reason. Kant argued a genuinely enlightened age required freedom to reason and argue in public, even while individuals still had to obey the specific laws and duties of their office in private.
Why it matters: Kant's essay became the period's most quoted self-definition, giving the Enlightenment a compact statement of its own goal that later historians and philosophers still use as the standard reference point when explaining what the movement was actually trying to do.
How we know: The essay survives in Kant's original German and in English translations; the Internet History Sourcebooks Project at Fordham University hosts the English text, and the Stanford Encyclopedia of Philosophy's entry on Kant dates the essay to 1784.
Author: Immanuel Kant · Work: An Answer to the Question: What Is Enlightenment? · Published: 1784 · Motto: Sapere aude (dare to know)
- August 26, 1789Well documented
Primary source · 2 sourceswhy?
Best source: Declaration of the Rights of Man - 1789
Cited as a "primary" source (no stronger domain match).The French Revolution Adopts the Declaration of the Rights of Man and of the Citizen
France's National Constituent Assembly adopted the Declaration of the Rights of Man and of the Citizen on August 26, 1789, six weeks after the storming of the Bastille. Its first article declared that men are born and remain free and equal in rights, and that social distinctions may be founded only on common usefulness. The document listed liberty, property, security, and resistance to oppression as natural and imprescriptible rights, and grounded political authority in the nation as a whole rather than in the king, drawing directly on Locke's and Rousseau's arguments that legitimate government exists to protect pre-existing rights and rests on the people's consent.
Why it matters: The Declaration converted decades of Enlightenment political philosophy into the founding constitutional statement of revolutionary France, and its universal language of the rights of man, rather than the traditional rights of a specific estate or corporation, gave later rights movements across Europe and its colonies a text to invoke directly.
How we know: The Declaration's text survives from the National Assembly's own records; the Avalon Project at Yale Law School and the World History Encyclopedia both preserve and document its August 1789 adoption and content.
Adopted: August 26, 1789 · Body: National Constituent Assembly · Key phrase: Men are born and remain free and equal in rights
SourcesRelated timelines- The French Revolution → · The Revolution that turned these ideas into a founding constitutional statement
- 1792Well documented
Primary source · 2 sourceswhy?
Best source: A Vindication of the Rights of Woman
Cited as a "primary" source (no stronger domain match).Wollstonecraft Publishes A Vindication of the Rights of Woman
Mary Wollstonecraft published A Vindication of the Rights of Woman in 1792, three years after the outbreak of the French Revolution and shortly after writing a defense of the revolution's principles against Edmund Burke. Wollstonecraft applied the Enlightenment's own arguments about reason and natural rights back onto the men making them, contending that women appeared inferior in reasoning and virtue only because they were denied the same education and were instead raised to please rather than to think. She argued that a political and social order built on reason, as the revolutionaries claimed theirs was, could not consistently deny women access to that same reason and the rights that followed from it, and that treating women as ornamental dependents amounted to a kind of domestic tyranny.
Why it matters: The Vindication is widely treated as the founding text of Western feminist political philosophy because it turned the Enlightenment's central tool, the appeal to universal reason and natural rights, directly against the era's own near-total exclusion of women from citizenship and education.
How we know: The Vindication survives in Wollstonecraft's original text; the Stanford Encyclopedia of Philosophy's entry on Wollstonecraft dates its 1792 publication and traces her argument from it.
Author: Mary Wollstonecraft · Work: A Vindication of the Rights of Woman · Published: 1792 · Key idea: Women's apparent inferiority is a product of denied education, not nature