Rousseau's famous work sets out the radical concept of the 'social contract': a give-and-take relationship between individual freedom and social order. If people are free to do as they like, governed only by their own sense of justice, they are also vulnerable to chaos and violence. To avoid this, Rousseau proposes, they should agree to give up some freedom to benefit from the protection of social and political organization. But this deal is only just if societies are led by the collective needs and desires of the people, and able to control the private interests of individuals. For Rousseau, the only legitimate form of government is rule by the people.