Jean Jacques Rousseau (1712-1778) is one of the most important European political philosopers, whose writings influenced both the French Revolution and later socialist theory. Born in Geneva, then an independent city state, he spent most of his life in France. His most important work, The Social Contract, was published in 1762 and is a classical work of republican political theory. It argues that sovereignty should be in the hands of the people, and that it should be exercised directly rather than delegated to a legislative assembly.

Thomas Paine was born in England in 1737, and moved to what were then Britain's American colonies at the age of 37. The American War of Independence began soon after, and Paine wrote a pamphlet entitled Common Sense in support of the colonists' right to self-government. Paine was supportive of the French Revolution from its outbreak in 1789, and wrote his book The Rights of Man (1791) in response to an attack on the revolution by the British conservative Edmund Burke. As well as attacking monarchy and inherited systems of privilege, Paine's work proposes a progressive income tax and something like a modern system of social welfare - revolutionary ideas at the time.

Part II

Karl Marx (1818-1883) was both a philospher and political activist. The Communist Manifesto, co-written with Friedrich Engels in 1848, gives the best short summary of his political philosophy and theory of history.