John Locke is arguably the father of liberalism. Considering that western democracy is founded on liberalism, this makes him one of the most important thinkers of all time.

John Locke’s ideas include the right to life, liberty, and the ownership of property, the right to not be owned as a slave, the non-aggression principle, the state of nature, and the social contract. Other important thinkers from Locke’s time include Hobbes and Voltaire.

His most notable work is his Second Treatise of Government. This book contains almost all the principles that America is founded on, and was largely the ideological backbone of the England’s Glorious revolution and the French revolution.