Markets regulate themselves best through an "invisible hand," with minimal government interference (The Wealth of Nations).
Argued punishment should be proportional to the crime, and opposed torture and the death penalty.
People are naturally selfish and need an all-powerful sovereign (Leviathan) to escape a brutish "state of nature."
Argued women are not naturally inferior to men, only denied equal education (A Vindication of the Rights of Woman).
Defined Enlightenment as humanity’s escape from "self-imposed immaturity," urging people to "dare to know."
Argued all knowledge comes from sensory experience, and was deeply skeptical of religion and miracles.
Doubted everything he could not prove through reason, arriving at "I think, therefore I am" (Cogito, ergo sum).
Relentlessly satirized the Catholic Church and absolute monarchy; championed freedom of speech and religious tolerance.
Compiled and edited the Encyclopédie, a massive project to gather and spread rational, secular knowledge.
Argued government power should be split into three separate branches to prevent tyranny (The Spirit of the Laws).
One of the Enlightenment’s most outspoken atheists, arguing the universe is purely material (System of Nature).
Early English writer who asked, "If all men are born free, how is it that all women are born slaves?"
Controversially argued God and Nature are one and the same (pantheism), applying reason to religion itself.
Championed the empirical scientific method — observe, experiment, and draw conclusions from evidence.
Natural rights to life, liberty, and property; government exists by the consent of the governed; the mind begins as a "blank slate."
Described universal gravitation and the laws of motion, showing the universe runs on discoverable, rational laws.
Society should be governed by the "general will" of the people; "man is born free, but everywhere he is in chains."
Used telescopic observation to support Copernican heliocentrism, clashing directly with the Catholic Church.