From Newton's laws to the Declaration of Independence: how scientists and philosophers in England, France, Scotland and Germany argued that reason could improve the world, and how their ideas crossed the Atlantic.
Stop 01 · 1543–1687
The Scientific Revolution
In 1543 Copernicus, working in Frombork in Poland, published his argument that the Earth goes round the Sun; the book was printed in Nuremberg in the year he died. Galileo, a professor at Padua, turned a telescope on the sky in 1609–1610 and described hundreds of stars invisible to the naked eye and four moons circling Jupiter. In 1633 the Inquisition found him 'vehemently suspect of heresy' and forced him to recant, and he spent his last years under house arrest. In 1687 Isaac Newton, in Cambridge, published the Principia, showing that the same laws of motion and gravity explain a falling apple and the orbits of the planets. If nature followed rational laws, many asked, why not society?
Cristiano Banti's 1857 painting Galileo facing the Roman InquisitionCristiano Banti · Public domain · Wikimedia Commons
In 1543 Copernicus, working in Frombork in Poland, published his argument that the Earth goes round the Sun; the book was printed in Nuremberg in the year he died. Galileo, a professor at Padua, turned a telescope on the sky in 1609–1610 and described hundreds of stars invisible to the naked eye and four moons circling Jupiter. In 1633 the Inquisition found him 'vehemently suspect of heresy' and forced him to recant, and he spent his last years under house arrest. In 1687 Isaac Newton, in Cambridge, published the Principia, showing that the same laws of motion and gravity explain a falling apple and the orbits of the planets. If nature followed rational laws, many asked, why not society?
John Locke went into exile in the Dutch Republic in 1683, after his patron, the Earl of Shaftesbury, fell from royal favour. He came home in 1689, travelling with Queen Mary II after England's Glorious Revolution, and that December published his Two Treatises of Government anonymously. He argued that people have natural rights to life, liberty and property, and that a government that violates them can rightly be replaced. The same year his Letter Concerning Toleration argued that religion is a matter for the individual and that churches are voluntary bodies. The Dutch Republic, where Locke had lived in exile, was by the 1720s a major centre for printing banned books and smuggling them into France.
In the 1700s Paris became the capital of the Enlightenment. Writers called philosophes, among them Voltaire, Montesquieu and Diderot, met in the salons of hostesses such as Madame Geoffrin and Julie de Lespinasse. Voltaire, sent into exile in England in 1726, praised English tolerance, science and smallpox inoculation in his Letters on the English, and had to hide from arrest when they appeared in French in 1734. Montesquieu's Spirit of the Laws (1748) argued for separating government powers; in 1751 the Church put it on its list of banned books. Diderot and d'Alembert's Encyclopédie, from 1751, set out to gather all human knowledge, and by 1772 it filled 28 volumes. Voltaire attacked censorship and religious intolerance.
On the morning of 1 November 1755, All Saints' Day, a great earthquake struck under the Atlantic south-west of Portugal. About 40 minutes later a tsunami surged into Lisbon's harbour and lower town, and candles lit for the feast started a firestorm that burned for hours. Some 85 per cent of the city's buildings were destroyed and around 30,000 to 40,000 people died in Lisbon, with perhaps 10,000 more in Morocco. Philosophers asked how a good God could allow such suffering. Voltaire mocked the optimism of Leibniz and Pope in his Poem on the Lisbon Disaster and, in 1759, in Candide; Immanuel Kant sought natural causes for earthquakes. The chief minister, Pombal, rebuilt the lower town with wide, straight streets.
Not every philosophe trusted progress. Jean-Jacques Rousseau, who signed his books 'Citizen of Geneva', blamed the toll at Lisbon on too many people crowding into cities. In April 1762 he published The Social Contract, printed in Amsterdam, which argued that only the general will of the people, not kings claiming divine authority, had the right to make laws. Émile, a treatise on education, followed. Both caused uproar: the Archbishop of Paris condemned him, his books were burned, and warrants went out for his arrest. Driven from France, Geneva and Bern, he found refuge at Môtiers in Neuchâtel, ruled by Frederick the Great. From 1792 Mary Wollstonecraft and later feminists criticised Rousseau for confining women to the home.
The Enlightenment had many centres. Scotland, with parish schools across the Lowlands and five universities, produced a remarkable circle of thinkers who argued daily in Edinburgh clubs such as the Select Society. There David Hume wrote on knowledge and human nature, though in his lifetime he was best known for his bestselling History of England. Adam Smith published The Wealth of Nations on 9 March 1776, founding modern economics. In Königsberg, writing in the December 1784 issue of the Berlin Monthly, Immanuel Kant defined Enlightenment as humanity's emergence from self-imposed immaturity, and gave it a motto, Sapere aude: 'Dare to know!' Ideas moved through letters, journals, academies and coffeehouses.
Some rulers took up Enlightenment ideas, without giving up power. Frederick the Great of Prussia, who called the ruler 'the first servant of the state', abolished most uses of judicial torture, allowed religious tolerance and invited Voltaire to Potsdam in 1750, though they parted angrily in 1753. Catherine the Great of Russia corresponded with Voltaire and Diderot, bought Diderot's library and hosted him in St Petersburg in 1773–74; yet under her the burden of serfdom grew, helping provoke Pugachev's Rebellion. Joseph II of Austria abolished serfdom in his lands and granted religious toleration in 1781. Historians call them 'enlightened absolutists'.
The colonists of British North America read Locke, Montesquieu and the Scottish writers. On 11 June 1776 the Continental Congress in Philadelphia appointed a Committee of Five, among them John Adams, Benjamin Franklin and Thomas Jefferson, to draft a declaration. Their Declaration of Independence, drafted by Jefferson and adopted on 4 July, declared that 'all men are created equal' with rights to 'life, liberty and the pursuit of happiness'. Its author held large numbers of people in slavery throughout his life. The US Constitution, drafted in 1787 in the same Pennsylvania State House, now Independence Hall, put Montesquieu's separation of powers into practice.
In 1789 the ideas came home. The French Revolution's Declaration of the Rights of Man and of the Citizen, adopted on 26 August, proclaimed liberty, equality and popular sovereignty; Lafayette had drafted it in consultation with his friend Jefferson, then the American envoy in Paris. Yet women, the poor and enslaved people were denied full citizenship, and in 1791 Olympe de Gouges answered with a Declaration of the Rights of Woman. Revolutionary ideas spread across Europe and Latin America, and to Saint-Domingue, where enslaved people rose up on 21 August 1791. Led by generals such as Toussaint Louverture, they won independence as Haiti on 1 January 1804. The story continues in our tour of the Age of Revolutions.