Rousseau describes sovereign in his essay "The Social Contract" as the collective voice of citizens within a society. Citizens, when unified, constitute the sovereign. When citizens act individually they do not wield the same power as when acting collectively.
Rather than placing authority and power within the law, Rousseau posits authority within the hands of citizens as they act collectively. In "The Social Contract," he compares the body politic to a physical body and says that they both inevitably will die. He claims that the "life principle" of a body politic lies in the sovereign or the collective voice of the people that sustain it. Laws mean nothing without the people there to enact, enforce, or break them. Rousseau claims that a state with a strong constitution and a strong governing body of laws will only grow stronger in time as the citizens continue to invest power within the state. The power of the laws ultimately stem from citizens investing within the laws. He conceives of power as not originating from the top of society but rather coming from the very bottom, as the assembled will of all citizens. However, the power of the sovereign only exists when citizens act collectively. Rousseau does not view isolated citizens as possessing any form of power.