The epigraph of the work is "foederis aequas / dicamus leges" Let us set equal terms for the truce. (Virgil, Aeneid XI.321–22). The stated aim of The Social Contract is to determine whether there can be a legitimate political authority, since people's interactions he saw at his time seemed to put them in a state far worse than the good one they were at in the state of nature, even though living in isolation. He concludes book one, chapter three with, "Let us then admit that force does not create right, and that we are obliged to obey only legitimate powers", which is to say, the ability to coerce is not a legitimate power―might does not make right, and the people have no duty to submit to it. A state has no right to enslave a conquered people.
Rousseau argues that legitimate authority must be compatible with individual freedom. Such authority can only be compatible with individual freedom if it is consented to, and hence there must be a social contract. However, Rousseau's conception of this social contract was different to that of thinkers before him, such as Grotius, Hobbes, and Pufendorf.[2]: 75 For Rousseau, since one's right to freedom is inalienable, the people cannot obligate themselves to obey someone other than themselves. Transferring rights to an authority involved renunciation of freedom and transformed the natural equality of men into subjection.[2]: 77 Hence, the only legitimate social contract is one that establishes the people themselves as the rulers. Rousseau refers to the united will of the people as the general will.[2]: 85 The general will, to be truly general, must only legislate laws with general form, i.e., laws that apply equally to all. For Rousseau, collective self-rule would increase freedom if the people to whom laws applied were also the ones prescribing them.[2]: 79 Rousseau, who objected to extreme wealth inequality, also argued that equality is essential for the attainment of liberty, and concluded that legislation ought to preserve equality.[2]: 80
Rousseau argues that the sovereign power must be separate from the government, which in Rousseau's terminology refers to the executive power. The division of sovereign from government is necessary because the sovereign cannot deal with particular matters like applications of the law.[2]: 89 Doing so would undermine its generality, and therefore damage its legitimacy. Thus, the government must remain a separate institution from the sovereign body. When the government exceeds the boundaries set in place by the people, it is the mission of the people to abolish such government and begin anew.
Rousseau claims that the size of the territory to be governed often decides the nature of the government. Since a government is only as strong as the people, and this strength is absolute, the larger the territory, the more strength the government must be able to exert over the populace (cf. also Turner's frontier thesis for the case of America). In his view, a monarchical government is able to wield the most power over the people since it has to devote less power to itself, while a democracy the least. In general, the larger the bureaucracy, the more power required for government discipline. Normally, this relationship requires the state to be an aristocracy or monarchy. When Rousseau uses the word democracy, he refers to an executive composed of all or most of the people (Bk. 3, Ch. 3, Para. 2) rather than to a representative democracy. Rousseau argues that it is the people themselves, not their representatives, who have supreme power, and that everyone taking part in legislation is a check against abuse of power.[2]: 83 In light of the relation between population size and governmental structure, Rousseau argues that like his native Geneva, small city-states are the form of the nation in which freedom can best flourish.[2]: 82 For states of this size, an elected aristocracy is preferable, and in very large states a benevolent monarch; but even monarchical rule, to be legitimate, must be subordinate to the sovereign rule of law.
