A massive societal shift was taking place, Cicero wrote, and it was laying waste to the foundations of the republic: through greed, ambition, and malice Rome’s leaders were squandering their republican inheritance. Nothing was more appalling to Cicero than the desperate deficit of enlightened and principled leadership. “Long before living memory our ancestral way of life produced outstanding men, and those excellent men preserved the old way of life and the institutions of their forefathers,” he observed. “Our generation, however, after inheriting our political organisation like a magnificent picture now fading with age, not only neglected to restore its original colours but did not even bother to ensure that it retained its basic form and, as it were, its faintest outlines.”

No wonder Cicero has been such a popular author among the champions of constitutional government. Renowned for his oratory, he rose through the ranks of Rome’s political order, serving as consul in 63 BC. As Anthony Everitt observes, Cicero’s rhetorical style can be detected in the speeches of Thomas Jefferson, William Pitt the Younger, Abraham Lincoln and Winston Churchill. The American Founders searched his writings for insights about how political communities either thrive or perish.

Unbridled, selfish ambition was among the greatest fears of the framers of the constitution. Republican government, they believed, offered the best hope of checking ambition and preserving both freedom and order — provided its citizens possessed the virtues necessary for self-government.

“In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself,” wrote James Madison in The Federalist Papers. “A dependence on the people is, no doubt, the primary control on their government; but experience has taught mankind the necessity of auxiliary precautions.”

The precautions against an oppressive state have largely atrophied. Why? In part because of the political abandonment of universal moral laws: their rejection has set loose the corrosive forces of factionalism. An ethos of relativism and materialism promises to eviscerate civic and political life, inviting greater state intervention.

Such was the Rome of Cicero’s day: a republic in name only, riven by divisions, corruption and remorseless violence. Yet until the moment that assassins took his life, he resisted dictatorships, for they represented a political community with a degraded conscience. For Cicero, Rome was in the dock. “Of this great tragedy we are not only bound to give a description,” he wrote, “we must somehow defend ourselves as if we were arraigned on a capital charge.”

Today, it seems, another great republic is on trial for its life. George Washington, known as America’s “indispensable man”, once warned of the global consequences should its experiment in self-government end in failure: “What a triumph for the advocates of despotism, to find that we are incapable of governing ourselves, and that systems on the basis of equal liberty are merely ideal and fallacious.”