Considerations on the Causes of the Greatness of the Romans and Their Decline

Montesquieu argues that Rome's greatness and decline were linked by a causal feedback loop: military expansion produced wealth, wealth produced luxury, luxury corrupted the civic virtue on which the republic depended, and corruption invited the internal conflicts that made Rome vulnerable to external threats . The effect became the cause. Rome's initial conditions — its martial spirit and institutional arrangements — were contingent, but once established they became path-determining through self-reinforcing loops. This is not a story of moral decline from an original purity but a systemic analysis of how success undermines the conditions of its own possibility.

The Considerations was published in 1734, fourteen years before The Spirit of the Laws, and functions as a case study in the method Montesquieu would later systematize . Where The Spirit of the Laws examines the general relations between laws, climate, commerce, and manners, the Considerations applies that comparative approach to a single society's entire history. It also prefigures The Spirit's analysis of despotism: the fear that governs the later Roman emperors mirrors the principle of despotic government. The work is best read not as mere history but as political philosophy conducted through historical analysis .

Rome provided the most complete case available for studying the full arc of a society's rise and fall, from its legendary founding in 753 BC to the fall of Constantinople in AD 1453 . Montesquieu also used Rome as a comparative lens, extensively contrasting it with Carthage, Greece, and Macedon. The choice was strategic: Rome's history was well documented, its trajectory dramatic, and its example inescapable for any eighteenth-century European thinking about empire and republicanism. Machiavelli's Discourses on Livy was the only comparable work, and Montesquieu's Considerations bears a deep kinship with it .

A common misconception reads the Considerations as a straightforward moralizing narrative of Roman virtue corrupted by vice. In fact, Montesquieu's method is more structural than moralistic. He describes Rome as a system with contingent initial conditions that become highly determining through feedback loops . He is less interested in blaming individuals than in tracing how institutions and incentives produce predictable patterns. The work is also not a simple celebration of the Roman republic: Montesquieu acknowledges the 'frightful tyranny' of the emperors as emerging from the general spirit the Romans themselves had cultivated .

The work is widely considered one of the first efforts to comprehend the whole span of Roman history, and it directly inspired Edward Gibbon's Decline and Fall of the Roman Empire . Gibbon acknowledged Montesquieu's influence, praising his 'energy of style' and 'boldness of hypothesis' . The Considerations also helped structure the later chronological division of history into Antiquity, the Middle Ages, the Renaissance, and early modernity . Its method of causal analysis applied to a single civilization prefigured the social-scientific historiography that emerged in the following centuries.

The Considerations is the least well known of Montesquieu's three major works, though scholars consider it among his best . The reasons are partly structural: it is shorter and more focused than The Spirit of the Laws, and less scandalous than Persian Letters. Its subject matter — Roman history — also seems more specialized to modern readers. Yet its value lies precisely in its concentration: it is one of the few instances where a philosopher undertakes an extended analysis of a single society's entire history, and its teaching about the relationship between power, wealth, and civic virtue remains directly relevant to political philosophy .