Book 2, Chapter 4 — The Limits of the Sovereign Power

If the State is a moral person whose life depends on the union of its members, it must have the power to direct each part toward the common good — as nature gives each person absolute power over their own limbs. But the existence of the public person does not abolish the private persons who compose it. Their lives and liberties are naturally independent of it, at least in matters that do not concern the community. The social compact asks each member to alienate only what the community needs; the question of what the community needs is left to the Sovereign — but the Sovereign's structural inability to harm all its members limits what it can rationally demand.

The argument is elegant in its circularity. Why is the general will always right? Because each citizen, when voting on matters that concern all, thinks of 'each' as meaning himself. The equality of rights and the idea of justice derive from the preference each person gives to themselves — extended, when voting as a citizen rather than an individual, to the community as a whole. The general will stays general only when it addresses general objects; when it addresses particular persons or particular facts, it becomes just another particular will, and loses its claim to rightness.

The practical consequence is that the Sovereign acts legitimately only through laws — general rules applicable to all. Athens, when it tried to legislate for specific individuals by particular decrees, was acting not as Sovereign but as magistrate — and badly at that. Particular judgments about particular persons belong to the government, not to the lawmaking body. The Sovereign can establish classes of citizens and rules for membership, but it cannot name anyone to any class by decree. The chapter anticipates the distinction between legislative and executive function that Book 3 will develop at length.