Had I the resources, the one new book I’d give every delegate to the national political conventions meeting later this month is James Traub’s masterful biography, “John Quincy Adams: Militant Spirit” (Basic Books).

Traub grabs your attention quickly, seven sentences in: “[Adams] did not aim to please, and he largely succeeded.”

Why? Because “he lived according to principles he considered self-evident. Others of his contemporaries did so as well, of course; what set Adams apart was that his principles were so inviolable that he eagerly sacrificed his self-interest to them. As president he accomplished very little of his ambitious agenda in part because he refused to do anything to reward his friends or punish his enemies. Such inflexibility is a dubious virtue for a politician.”

That’s on page xi. Some 544 pages later, I had gotten the distinct impression that Traub wished there were a bit more principled inflexibility and disdain for self-interest in our politics today. And truth to tell, James Traub signals his admiration for his subject early on, cataloguing others of Adams’ virtues that we’d do well to find exemplars of today:

“Though he never wore a uniform or saw battle, Adams was a figure of immense physical and moral courage. His bravery was a form of patriotism. So complete was his identification with the nation that came into being when he was a boy of nine that he did not flinch at either the prospect of death or – what may be harder for men of great ambition – the wreckage of his career, so long as he believed that service to the nation required it.”

John Quincy Adams had a lot going for him: two remarkable parents, Abigail and John; natural gifts of intellect; a ferocious capacity for work; a heart that could be touched by tenderness. Yet, what struck me in pondering his long life, during which he served in more great offices to greater effect than perhaps any other American, was Adams’ constant determination to live virtuously. He believed that there were moral truths built into the world and into us; that we can know those truths by reason; that knowing those truths, we know our obligations; and that, with that knowledge, we find the measure of how we should behave.

His commitment to be a man of virtue went hand-in-glove with an abiding concern about the fragility of democracy – another recurring theme in Adams’ long life in the arena. Nor was he alone in his determination and concern. James Madison may have drafted the Constitution knowing that he was not crafting an instrument of governance for angels. But Madison and the other founders and framers – be they Anglicans, Congregationalists, Unitarians, Baptists, Calvinists, or the occasional Catholic – were convinced that only a virtuous people could sustain an experiment in democratic self-governance over time, and they worried, rightly, that a virtue-deficit, especially one that expressed itself in what they called “faction,” could unravel the new republic.

Similar concerns about republican fragility are probably not high on the worry-list of most convention delegates heading for Cleveland or Philadelphia this month. But they should be. The machinery of our democracy is not working very well right now. Authoritarian winds are blowing at both ends of the ideological spectrum. Political correctness is rotting our political culture, in a debauchery exacerbated by vulgar reactions to the “pc” police. “Faction,” in the form of gender, racial or ethnic tribalism, is everywhere.

How many 2016 convention delegates suspect that the national discontent has something to do with a virtue-deficit in our national political culture? How many public officials, and how many of those who seek to lead us, know, like John Quincy Adams, the line they will not cross, if principle demands “Stop here”?

Adams was the last great Puritan in American public life, most frequently celebrated today for his role in the Amistad case, in which he struck a blow against America’s original sin, slavery. To my mind, however, John Quincy Adams stands out as a model for 21st-century American politicians because he did not aim to please, but to do the right thing, irrespective of the cost.

George Weigel is a senior fellow of the Ethics and Public Policy Center in Washington, D.C.