John Locke (1632-1704) was an English philosopher who argued that government rests on the consent of the governed and exists to protect natural rights (life, liberty, property), directly challenging divine-right absolutism and shaping the Enlightenment.
John Locke was a 17th-century English philosopher whose Two Treatises of Government (1689) flipped the logic of political power. Instead of kings ruling by divine right or tradition, Locke argued the state originates in a social contract, an agreement among self-interested individuals who consent to be governed in exchange for protection of their natural rights to life, liberty, and property. If a ruler violates that contract, the people can legitimately replace him. That's exactly the argument English elites used to justify kicking out James II in the Glorious Revolution of 1688.
Locke also matters on the intellectual side. His idea of tabula rasa (the mind as a blank slate shaped by experience) challenged the belief that humans are born with fixed, innate ideas, including original sin. If people are products of their environment, then better education and better institutions can produce better people. That optimism about human improvement became a core assumption of the Enlightenment. The CED names Locke directly in KC-2.3.III.A and pairs him with Rousseau in KC-2.3.I.B as the architects of natural rights and social contract theory.
Locke lives at the hinge between Unit 3 (Absolutism and Constitutionalism) and Unit 4 (Scientific, Philosophical, and Political Developments). For Topic 3.2 and learning objective AP Euro 3.2.A, he's the philosopher who explains the consequences of the English Civil War and Glorious Revolution, since his Two Treatises gave the constitutional settlement of 1688-89 its theoretical justification. For Topic 4.3 and objectives AP Euro 4.3.A and 4.3.B, he's named in the essential knowledge (KC-2.3.III.A) as the thinker who argued the state comes from consent of the governed rather than divine right or tradition. He also supports Topic 3.8 (AP Euro 3.8.A) comparisons, because Locke's England is the constitutionalism half of the absolutism-versus-constitutionalism contrast you'll be asked to make against Louis XIV's France. If you can use Locke in all three places, you're thinking the way the exam wants.
Keep studying AP Euro Unit 4
Social Contract and Natural Rights (Unit 4)
These are Locke's two signature ideas, and the CED (KC-2.3.I.B) credits him and Rousseau with developing them. The key move is that rights come from nature, not from the king, so government is a deal that can be broken if the ruler fails to protect those rights.
The Glorious Revolution (Unit 3)
Locke's Two Treatises appeared in 1689, right as Parliament replaced James II with William and Mary. His theory reads like an after-the-fact permission slip for the revolution, which is why the 2017 DBQ asked whether the Glorious Revolution counts as part of the Enlightenment at all.
Tabula Rasa and the Scientific Revolution (Unit 4)
Locke applied the Scientific Revolution's empirical method to the human mind. Knowledge comes from observation and experience, not innate ideas, which is the same observation-over-tradition logic that Topic 4.7 traces from Copernicus and Newton into politics and society.
Adam Smith and Enlightenment Liberalism (Unit 4)
Locke's emphasis on property rights and self-interested individuals feeds directly into Smith's free-market challenge to mercantilism (KC-2.3.III.B). Together they form classical liberalism, the ideology the 2021 DBQ asked you to test against British rule in India.
Multiple-choice questions love two angles on Locke. First, contrast with Hobbes, asking how Leviathan (1651) and Two Treatises (1689) differ on sovereign authority and human nature. Second, mechanism questions asking how his theories challenged absolutism (answer: consent of the governed undercuts divine right). Tabula rasa also shows up as a challenge to prevailing beliefs about innate ideas. On the essay side, Locke is high-value DBQ evidence. The 2017 DBQ asked whether the Glorious Revolution was part of the Enlightenment, and Locke is the natural bridge between the two. The 2021 DBQ on liberalism and British India rewards knowing Locke as a root of liberal ideology. Drop him into Topic 3.8 comparison essays as the theorist behind English constitutionalism, set against Bossuet and Louis XIV on the absolutist side.
Both are English social contract theorists, but they reach opposite conclusions. Hobbes (Leviathan, 1651), writing during the chaos of the English Civil War, saw humans as naturally violent and argued people surrender their rights permanently to an absolute sovereign to escape the brutal state of nature. Locke (Two Treatises, 1689), writing after the Glorious Revolution, saw the state of nature as mostly reasonable and argued people only lend power to government conditionally, keeping the right to overthrow a ruler who violates natural rights. Same contract framework, opposite verdicts on absolutism. MCQs test exactly this difference.
Locke argued that government originates in the consent of the governed through a social contract, not in divine right or tradition, which is the exact language of KC-2.3.III.A.
His natural rights were life, liberty, and property, and a government that fails to protect them can legitimately be overthrown.
Two Treatises of Government (1689) served as the philosophical justification for the Glorious Revolution and English constitutionalism.
Tabula rasa, the idea that the mind starts as a blank slate shaped by experience, applied the Scientific Revolution's empiricism to human nature and challenged belief in innate ideas.
Locke versus Hobbes is the classic AP Euro contrast: both used social contract theory, but Hobbes defended absolute sovereignty while Locke defended limited, revocable government.
Locke's ideas flow forward into Enlightenment liberalism, Adam Smith's economics, and the American and French Revolutions, making him strong DBQ evidence across Units 3 and 4.
Locke believed people are born with natural rights to life, liberty, and property, and that government exists only by the consent of the governed through a social contract. In Two Treatises of Government (1689), he argued a ruler who violates that contract can be legitimately removed.
Both used social contract theory, but Hobbes's Leviathan (1651) said people permanently surrender power to an absolute sovereign to escape a violent state of nature, while Locke's Two Treatises (1689) said power is conditional and revocable. Hobbes justifies absolutism; Locke justifies limited government and revolution.
No. The Glorious Revolution happened in 1688 for political and religious reasons (fear of James II's Catholicism and absolutist moves), and Locke published Two Treatises in 1689, afterward. His work justified the revolution rather than causing it, a distinction the 2017 DBQ on the Glorious Revolution and the Enlightenment rewards.
Tabula rasa is Locke's idea that the mind begins as a blank slate filled in by experience and sensation. It challenged belief in innate ideas (including original sin) and implied humans can be improved through education and reformed institutions, a core Enlightenment assumption tested in Topics 4.3 and 4.7.
Both. He appears in Unit 3 as the theorist behind English constitutionalism after the Glorious Revolution (Topic 3.2) and in Unit 4 as a named Enlightenment thinker who developed natural rights and social contract theory (Topic 4.3, KC-2.3.I.B).