act in the common good. This expediency argument attracted many of the early proponents of sovereignty. Hobbes strengthened the definition of sovereignty beyond either Westphalian or Bodin's, by saying that it must be: Absolute: because conditions could only be imposed on a sovereign if there were some outside arbitrator to determine when he had violated them, in which case the sovereign would not be the final authority. Indivisible: The sovereign is the only final authority in his territory; he does not share final authority with any other entity. Hobbes held this to be true because otherwise there would be no way of resolving a disagreement between the multiple authorities. Hobbes' hypothesis—that the ruler's sovereignty is contracted to him by the people in return for his maintaining their physical safety—led him to conclude that if and when the ruler fails, the people recover their ability to protect themselves by forming a new contract. Hobbes's theories decisively shape the concept of sovereignty through the medium of social contract theories. Jean-Jacques Rousseau's (1712–1778) definition of popular sovereignty (with early antecedents in Francisco Suárez's theory of the origin of power), provides that the people are the legitimate sovereign. Rousseau considered sovereignty to be inalienable; he condemned the distinction between the origin and the exercise of sovereignty, a distinction upon which constitutional monarchy or representative democracy is founded. John Locke, and Montesquieu are also key figures in the unfolding of the concept of sovereignty; their views differ with Rousseau and with Hobbes on this issue of alienability. The second book of Jean-Jacques Rousseau's Du Contrat Social, ou Principes du droit politique (1762) deals with sovereignty and its rights. Sovereignty, or the general will, is inalienable, for the will cannot be transmitted; it is indivisible since it is essentially general; it is infallible and always right, determined and limited in its power by the common interest; it acts through laws. Law is the decision of the general will regarding some object of common interest, but though the general will is always right and desires only good, its judgment is not always enlightened, and consequently does not always see wherein the common good lies; hence the necessity of the legislator. But the legislator has, of himself, no authority; he is only a guide who drafts and proposes laws, but the people alone (that is, the sovereign or general will) has authority to make and impose them. Rousseau,