Freedom is an important theme in the Discourse on Inequality and in The Social Contract. The only purpose of the state, Rousseau argues, is to secure the freedom of the citizens, and the worst system of government is that in which the most people are not free. Indeed, The Social Contract is an attempt to create a society in which freedom for all is possible. In contrast, Discourse on Inequality describes a situation in which no one can really be free.

The domination of one person by another reduces that person's freedom to act. Property and laws also affect the citizen's freedom, but those who agree to them generally believe that they are a reasonable restraint on their liberty. In practice, however, real freedom within society is impossible because inequality and property lead inevitably to domination. Only in the state of nature, or in a radically different type of society, could real freedom exist. This is an insight that Marx and Engels picked up in The Communist Manifesto.

Rousseau's description of freedom does not rely on political institutions and laws alone, however. It also includes an idea of psychological freedom, or freedom from need. Modern man is not free partly because others dominate and exploit him, but also because he is the slave of his own needs. As long as man needs others, or relies upon their opinions, he can never be free. Savage man is free in both senses of the term, because he does not depend on others, and cannot be dominated. Rousseau is clear that this type of primitive freedom is no longer possible in the modern world: to find out what sort of freedom he thinks can be achieved, you need to read The Social Contract.