The term “moderation” has an antiquated ring. It is rarely heard these days except to mock those who are afraid to offend and eager to please.

This reflects the impoverishment of our moral vocabulary. It is also a consequence of the excess of our politics, which promotes scorn for the balancing and blending of worthy but rival principles that moderation, in the proper sense of the term, accomplishes.

The three remaining presidential candidates casually flirt with the extremes. Donald Trump’s vulgar rhetoric, ignorant utterances, and crude, off-the-cuff policy prescriptions reveal contempt for the norms of public discourse.

In conducting the vast bulk, if not the entirety, of her email correspondence as secretary of state on a homebrew computer server, Hillary Clinton not only exposed those communications to routine interception by foreign powers but also flouted her obligation as a State Department official to ensure that her emails remained under government supervision and available, in accordance with the Freedom of Information Act, for public inspection.

Meanwhile, Bernie Sanders thunders on about the imperative for government to provide health care and a college education to all citizens without plausibly explaining where, with a national debt racing toward $20 trillion and with national entitlement programs hurtling to insolvency, the money will come from to fund his extravagant promises.

In “Democracy in Moderation: Montesquieu, Tocqueville, and Sustainable Liberalism,” Paul Carrese puts the political turbulence of the present moment in perspective. The propensity toward partisanship and polarization so conspicuous in today’s politics, he observes, has antecedents in America’s founding. But also present at the founding, he argues, was a sophisticated “philosophy of moderation” that underwrote American constitutional government.

Liberal democracy is in need of moderation, Carrese writes, because it is home to clashing principles. Primary among these is the clash between the democratic principle that the people rule and the principle of liberty that imposes limits on the will of the majority through the protection of individual rights.

Contending interests will also proliferate because the unscripted actions of free people, coming from different backgrounds and endowed with diverse abilities and dispositions, will generate a multitude of disparate attachments, preferences, and opinions.

Liberal democracy also encourages traits that destabilize it. Emancipated from traditional constraints, we restlessly seek material enjoyment; spurn the civilizing formalities of dress, speech, romance and courtship, and law; and neglect the responsibilities of an engaged civic life in favor of the pleasures of private affairs.

From this Tocquevillian analysis, Carrese draws a Tocquevillian conclusion: Liberal democracy “in moderation would aim to strike the right balance among its several defining principles, while also tempering its endemic weaknesses or tendencies toward extremes.”

A professor of political science at the United States Air Force Academy, Carrese reconstructs the intellectual origins of the moderation that informs the American constitutional order. But his aim goes beyond the scholarly. Alarmed by the immoderation of our culture and politics, Carrese seeks to recover an understanding of the principles of government and the qualities of character that remain essential to conserving liberal democracy in America.

Although the writings of Charles-Louis de Secondat, Baron de La Brède et de Montesquieu are seldom included in university surveys of modern political thought anymore, the 18th century French philosopher and jurist, according to Carrese, “was the most important source” of the spirit of the American Constitution and the institutional innovations that distinguished it. The only authority quoted more often by America’s founding generation than the Frenchman generally known simply as Montesquieu was the Bible.

Every political order, Montesquieu stressed in his 1748 masterpiece, “The Spirit of Laws”, is a distinctive blend of customs and practices, geography and climate, aspirations and ideas, and associations and institutions. From this unusual appreciation of the diversity of factors that shape political life, it is a short step to the central principle of Montesquieu’s political science: “The spirit of moderation ought to be that of the legislator; the political good, like the moral good, is always found between two limits.”

Montesquieuian moderation, Carrese argues, is institutionalized in the U.S. Constitution.

“In order to form a moderate government,” Montesquieu wrote, “one must combine powers, regulate them, temper them, make them act; one must give one power a ballast, so to speak, to put it in a position to resist another; this is a masterwork of legislation, that chance rarely makes, and prudence rarely is allowed to produce.” A more compact statement of the daunting task that the delegates to the Constitutional Convention of 1787 took upon themselves—and of their enduring accomplishment—would be hard to come by.

George Washington was called out of retirement to preside over the extended deliberations in Philadelphia. His sterling reputation and calming presence were widely seen as crucial to the risky attempt to save the Union by replacing the feeble Articles of Confederation with a new charter of government that would be extensive and energetic enough to protect liberty while painstakingly limited through the separation of powers and federalism to prevent it from strangling liberty.

Carrese sees Washington’s career as exemplifying moderation in action, not least in his two great decisions to relinquish power—first after leading America to victory in the Revolutionary War and then after two terms as president—when his grateful countrymen might well have conferred on him unfettered authority for life. Speaking for those on both sides of the Atlantic who observed in awe Washington’s returns, on moral and patriotic grounds, to private life, King George III said that these acts put Washington “in a light the most distinguished of any man living,” and established him as “the greatest character of the age.”

Carrese calls attention to the spirit of moderation that runs through Washington’s great Farewell Address of 1796. Of particular salience in this disconcerting election year is the first president’s warning about “the spirit of party” which, Washington wrote, “is inseparable from our nature, having its root in the strongest passions of the human mind.” Although the tendency to pursue narrow private ambitions and one-sided group claims at the expense of the public interest exists under all forms of government, in democracies the party spirit “is seen in its greatest rankness, and is truly their worst enemy.”

Partisanship, Washington acknowledged, can contribute to keeping government in check and preserving liberty. But what keeps partisanship in check?

“Habits of thinking” and “virtue or morality” is George Washington’s answer. “Promote then, as an object of primary importance, institutions for the general diffusion of knowledge,” he exhorted his countrymen. “In proportion as the structure of a government gives force to public opinion, it is essential that public opinion should be enlightened.”

In 2016 as in 1796: If we want the electorate to choose public officials who will balance and blend the worthy but rival principles in which liberal democracy is grounded, we must ensure that our schools provide an education in moderation—in the proper, demanding, and constitutional sense of the term.