When it comes to the use of prudence, in fact, Anton, one of the original palace intellectuals of the Trump transition, has been here before. In his view, it is one of a number of principles of classical statecraft that should be invoked to help America set itself back on the right track in foreign affairs. In an essay for American Affairs written before he was appointed to the administration, Anton offered a strongly worded critique of what he saw as the Washington national-security establishment’s unthinking fidelity to the idea of “liberal international order.” Rather than retreat into isolationism, however, Anton expressed the belief that powerful nations, such as the United States, had to strike a balance between “contempt” and “prestige.” Being held in contempt damaged a nation’s ability to influence others, and the only antidote was to be respected or “even a little bit feared.” Striking this delicate balance was the clue to a successful foreign policy, he argued, “which means prudence is always required.”

Unlikely as it may sound, then, “prudence” is circulating as a working concept among the various foreign-policy groupings within the Trump White House. Does this mean that we are witnessing the green shoots of a new consensus where there was once civil war? Might a commitment to prudence as an operating principle offer the Trump administration the coherence many fear it lacks, or the intellectual basis for the next National Security Strategy? Or, as seems more likely, will the definition of twenty-first-century prudence—of considered counsel to the Prince—remain contested terrain?

PRUDENCE ASSUMES no system, schematic or strategic script. Therein lies much of its merit. It has both classical and Christian antecedents, but it is by nature ambivalent, historically conditioned and somewhat elastic.

Nor is its exercise something that sits easily with the character of modern democracy. In Democracy in America, Alexis de Tocqueville noted that the democratic system seemed to grind against the traditional requirements of statecraft. He warned that “foreign politics demand scarcely any of those qualities which a democracy possesses; and they require, on the contrary, the perfect use of almost all those faculties in which it is deficient.” When it came to its dealings with other states, a democracy

“cannot combine its measures with secrecy, and it will not await their consequences with patience. . . . [Democratic polities] obey the impulse of passion rather than the suggestions of prudence, and . . . abandon a mature design for the gratification of a momentary caprice.”

Such fears of imprudence weighed heavily on the minds of American strategists during the Cold War. One of the greatest challenges faced by the United States was always assumed to be the management of its passions and its purse. Thus Dwight Eisenhower’s “New Look” emphasized strategic patience, cautious containment and long-term sustainability as the best means of outlasting the Soviet Union. This implied caution in fiscal, temperamental and military affairs, as a counterbalance to the irrationalism and emotionalism that led to foreign-policy misadventure.

It was in this context that Cold War prudence was often taken to denote frugality or restraint, with which it was only situationally connected. Prudence was seen as the antidote to unwieldy idealism or democratic excitability, and thus was assumed to be the handmaiden of realism writ large. Its definition was narrowed to never exceeding the pragmatic bounds set by the national interest. This was how it lived on in much academic literature on realism thereafter, notably in the work of Hans Morgenthau, who wrote that “there can be no political morality without prudence; that is, without consideration of the political consequences of seemingly moral action.” In The Tragedy of Great Power Politics, John Mearsheimer went one step further. For states in an anarchic system, “prudence dictates that they behave according to realist logic.” Understood in this way, prudential reasoning implied the tethering of ideological excess, or concomitant military overstretch.

And yet the essential point of prudence is that it rarely dictates. As is often the case, Reinhold Niebuhr provided a more nuanced perspective in his writings. He agreed that there was an important role for “prudent self-regard” in shaping nations’ foreign policy. But he also objected to what he saw among some realists as an attenuated understanding of prudence, as some sort of “procedural standard” for foreign-policy decisions—or an aide-memoire to keep the national interest paramount at all times. The real purpose of prudence was to mediate between the three other cardinal virtues—temperance, courage and justice. In many circumstances, it was true that prudential reasoning would advise self-restraint. But true prudence would also consider the demands of courage and justice. Thus, in Niebuhr’s view, “any kind of prudence which estimates common problems from the perspective of a particular interest will define the interest too narrowly.” Human beings could not escape a feeling of “loyalties and responsibilities to a wider system of values than that of the national interest—to a civilization for instance, to a system of justice, and to a community of free nations.” This broader sense of justice, Niebuhr suggested, “must prevent prudence from becoming too prudential in defining interest.” Its job was to secure some sort of equilibrium, to “safeguard against both sentimentality and moral cynicism.”

The origins of prudence can be traced to the Athenian understanding of politics, as it developed in the aftermath of defeat in the Peloponnesian Wars. Aristotle distinguished between three “virtues of thought”: episteme (scientific knowledge), techne (craft knowledge) and phronesis (prudence, or practical wisdom). As he explained in the Nicomachean Ethics, phronesis derived from experience. It was “concerned with particulars as well as universals, and particulars become known from experience.” Its main business was “to determine not ends but means to ends, i.e., what is most useful to do.” More than that, however, phronesis also demanded powers of advocacy and rhetorical skill to persuade citizens of the most expedient course of action. The Latin word prudentia is one possible translation of phronesis, and conveys its journey from Athens to Rome. For Roman political thinkers and statesmen like Cicero, concerned with the res publica (the public thing), it was the virtue most important for senators engaged in governing the civitas.

In the hands of the Christian ethicists, the Western understanding of prudence evolved further still, as a situational ethic as well as a guide to reason. For St. Thomas Aquinas,

“Rightness of choice necessarily involves two factors, namely a due end and something suitably ordained to that due end. . . . Consequently, an intellectual virtue is needed in [a man’s] reason to complement it and make it well adjusted to these things. This virtue is prudence.”

Aquinas’s Secunda Secundae of the Summa Theologica was in part devoted to finding a synthesis of classical and Christian thinking on prudence. Following Aristotle, he considered prudence a form of practical reason, based on experience and shrewdness. It was intimately concerned with euboulia (deliberating well), and synesis (judging well). Doing God’s will on earth remained the priority of a cloistered thinker like Aquinas. But he understood that political prudence also implied scenarios in which “even as false is found with true, so is evil mingled with good.” In this spirit, as the Anglo-Australian political philosopher Kenneth Minogue later observed, “prudence is a joker in the moral pack, and its business, on occasions, is to trump its fellow virtues.”

It was partly in response to the excesses of religious enthusiasm in early modern Europe that prudence moved from the domain of individual ethics to assuming a greater role in the affairs of the state. It was this that encouraged the emergence of the practice of “prudent counsel.” A wise prince would make use of experienced counselors, learned in history but promising insight into how the maxims of practical reasoning might apply to the contingent circumstances of the present. With politique raison d’état, writers and counselors as varied as Machiavelli, Jean Bodin and the Dutch humanist Justus Lipsius sought to offer more than abstract moral injunctions when it came to questions of war and governance. Instead, they offered a distinctive counsel of prudence, or practical morality. This was based on their reading of historical, usually classical precedents, informed by a neo-Stoic ataraxia that valued calmness of mind as the antidote to zealotry.

Titian’s 1565 Allegory of Time Governed by Prudence graphically captured this evolving understanding of political wisdom. The painting depicts a man with three faces: a mature adult faces the viewer, flanked on one side by the wizened profile of an old man and on the other by the callow features of a youth. Beneath the three-faced figure sits a three-faced beast—a lion facing the viewer, profiled by a wolf on one side and a dog on the other. Across the top of the painting runs the maxim EX PRAETERITO PRAESENS PRUDENTER AGIT, NI FUTUREM ACTIONEM DETURPET: “From the experience of the past, the present acts prudently, lest it spoil future actions.” The painting may be read both as a depiction of the three ages of man and, symbolically, of a wolf devouring the memory of the past, a lion depicting the fortitude necessary in the present and a dog bounding into the future. True prudence deployed the wisdom of the past as a guide to the present, with an awareness of the need to prepare for the future.