Roman Empire period

The Roman imperial period is Rousseau’s historical example of a republic’s degeneration into rule sustained by professional troops and concentrated authority. He contrasts the citizen soldiers of early Rome with the paid forces of the late Republic and the emperors, arguing that military expansion can impoverish a population, weaken its stake in public affairs, and help rulers subordinate the people. Rome’s later despotism completes the argument: when government usurps sovereignty, the political compact is broken and the state is dissolved.

From citizen soldiers to paid troops

Rousseau presents the change in Rome’s military system as part of a wider loss of civic commitment. Early Roman victories, like those of Alexander, were won by citizens prepared to risk their lives for their country but unwilling to sell their service. Payment of the Roman infantry began only at the siege of Veii. In the Jugurthine War, Marius further altered the character of the legions by admitting freedmen, vagabonds, and other mercenaries.

The imperial period represents the further development of this shift. As citizens ceased to regard the common cause as their own, magistrates could prefer the command of mercenaries to that of free citizens. Rousseau argues that paid forces were useful not only against foreign enemies: rulers could also use them to bring their own countrymen into submission. Military dependence thus signaled a political change, from a community defended by citizens to a population watched over by forces answerable to rulers.

The costs of maintaining an army

Rousseau traces a reinforcing economic and political chain. Recruiting soldiers removed labour from the land, reducing the supply of provisions; maintaining troops required taxes, which raised prices. Public murmurs prompted increases in troop numbers, and the resulting hardship deepened popular distress, which in turn became a reason for further military expansion. The attempt to suppress the effects of the system consequently intensified its causes.

The mercenaries’ allegiance sharpened the contrast. Rousseau describes them as prizing their status as Caesar’s satellites above that of defenders of Rome. Their obedience was directed toward commanders rather than the laws or fellow citizens whose bread supported them. He identifies the regular troops maintained by tyrants as ostensibly a defence against foreign threats but, in practice, a means of enslaving the countrymen they were supposed to protect. In his account, this military structure was one of the principal causes of the Roman Empire’s ruin.

Sovereignty and dissolution

Rome also supplies Rousseau with a political endpoint for his account of institutional decline. The abuse of aristocratic government led to civil wars and the triumvirate; Sulla, Julius Caesar, and Augustus became monarchs in fact, and under Tiberius’s despotism the state was dissolved. Rather than disproving Rousseau’s theory of political change, Roman history confirms it: government may change in character as it departs from the people’s sovereign authority.

Rousseau’s general account of dissolution explains the force of this conclusion. When a prince ceases to administer the state according to its laws and usurps sovereign power, the state contracts into a separate body composed of the government’s members, while the rest of the population is reduced to subjects of its rule. The social compact is then broken, and citizens recover their natural liberty, though they may still be compelled to obey. The Roman imperial period therefore figures not simply as a sequence of rulers, but as the culmination of a political transformation in which military dependence and government usurpation accompany the loss of a free civic order.