Jean-Jacques Rousseau’s The Social Contract, or Principles of Political Right (1762) is an analysis of the contractual relationships which may be necessary for legitimate government, and is an explanation of how these relationships may combine principles of justice and utility. Rousseau argues that civil society is based on a contractual arrangement of rights and duties which applies equally to all people, whereby natural liberty is exchanged for civil liberty, and whereby natural rights are exchanged for legal rights. The terms of the contract provide assurance that civil laws promote the public good rather than the private good of particular individuals or groups. If the contract is breached by a government which usurps the sovereignty of its people, then the people are no longer obligated to submit to that government and consequently regain their natural liberty.
According to Rousseau, justice cannot be defined as 'the right of the strongest,' or the power of some individuals to gain advantage over others. If justice were the same as the power to gain advantage over others, then the most powerful individuals would always be the most just and morally right. Moreover, if justice were the power to force an individual to yield to a particular demand, then there would be no obligation for an individual to comply with a lawful authority unless that authority had the power to force the individual to comply. Thus, the question of whether justice can be achieved in society may not depend on whether individuals can be forced to comply with civil authority but on whether individuals and civil authority can act in harmony with, and fulfill their moral obligations toward, each other. Rousseau also argues that there may be a moral obligation to comply with civil authority only if that authority is legitimate (i.e. based on a fair and just agreement among the members of society).
Rousseau argues that, in order to protect themselves and their