Religious tolerance isn’t exactly popular these days. The ethno-religious violence coursing through and from the Muslim Middle East has been compared with the Thirty Years’ War, and for once the analogy does not seem misplaced. The major European countries swing between ultra-accommodating and ultra-suspicious or xenophobic attitudes toward the ethnic and religious minorities in their midst, especially but not only the newcomers. In America, whose founders turned religious toleration into the natural right of all, significant cracks, mainly of a different kind, have opened in the constitutional guarantee of religious freedom.

In search of wisdom on these matters, is there anything to be learned from the philosophers and statesmen of the 17th and 18th centuries who first articulated and defended the modern idea of religious tolerance? Incongruous as it may sound, a recent off-Broadway staging of a 1779 work by a German philosopher investigates this very possibility—and to surprisingly illuminating effect.

The philosopher in question was Gotthold Ephraim Lessing (1729 – 1781), and the name of his play, or “dramatic poem” as he called it, is Nathan the Wise. Like Friedrich Nietzsche a century later, Lessing was born the son of a Lutheran minister in Saxony and studied at Leipzig. Although most philosophers of his time wrote treatises, Lessing dabbled in and mastered an astonishing number of literary styles, penning art and theater criticism, epigrams, and essays on theology as well as comedies and tragedies. He also formed a lifelong friendship with the German-Jewish philosopher Moses Mendelssohn (1729-1786), a figure who to Lessing and his contemporaries embodied the possibility of transcending religious difference and of creating a “friendship in the truth”—the truth, that is, of reason. It was upon Mendelssohn that Lessing largely modeled the character of Nathan the Wise.

In the century following Lessing’s death, Nathan the Wise was performed less frequently than some of his other comedies and tragedies; as a drama with plainly political implications, it went through fits of hot and cold reception. The Nazis completely banned it. Since World War II, however, it has seen something of a revival in the new Europe, where the “tolerance” part of religious tolerance has assumed the fixity of an article of faith.

Lessing’s play is set “around 1192” CE in the Jerusalem of the Third Crusades—a moment chosen for its atmosphere of high religious tension. The Muslim sultan Saladin, newly installed as ruler in the city, maintains a relatively tranquil order against a backdrop of potentially sudden outbreaks of violence. In that order, Jews, Muslims, and Christians come together through a series of astonishing though explicitly non-miraculous coincidences.

Thus, while Nathan is away in Babylon on business, his daughter Rachel is rescued from fire by a Christian knight Templar, who is spared from execution (the fate decreed by Saladin for all other Templars) because of his resemblance to the Muslim leader’s dearly departed brother. Meanwhile, the Templar, having fallen in love with Rachel, discovers that she is actually an orphaned Christian adopted and raised by Nathan as a Jew. Although gallant, the Templar is also a hot-headed fanatic, and the revelation seems destined to destroy both Nathan’s tranquility and the fragile peace of the city.

In navigating and ultimately overcoming these fraught circumstances, Nathan displays “wisdom” in the full sense. He is both a master of political circumstances and one who understands both what we can and cannot know about the highest and most important things: in short, an emblem of true, universal humanity. As one of his friends attests, Nathan “treats alike” the practitioners of Judaism, Christianity, Islam, and Zoroastrianism. (The last-named, to the enlightened German mind—see especially Mozart’s opera The Magic Flute—usually suggests a form of religion fit for philosophers.)

This spring’s production of Nathan the Wise by New York’s Classic Stage Company was clearly informed by the sense that religious tolerance is under threat in today’s world—an impulse responsible for a few unfortunate gimmicks designed to broadcast political sympathies and convey “relevance.” Among these were a backdrop photo of a bombed-out neighborhood in contemporary Syria and cameo intrusions of modern Arabic and Hebrew, all seemingly expressive of a “do not be mean to Muslims” message. Other annoyances included the regrettable disregard for Lessing’s extraordinary care in choosing his every word; in this respect, a literal translation of the original German would have been preferable to Edward Kemp’s fluid but at times overly idiomatic English adaptation.

Still, the play’s inherently dramatic qualities were conveyed quite well, which makes it all the more regrettable that its run was so brief. F. Murray Abraham, best-known for his unforgettable Salieri in Amadeus (1984), brilliantly portrayed Nathan as ironic but never cold, and most of the other performers were better than fine. Above all, this spring’s production of Nathan the Wise offered much food for thinking through Lessing’s brief for religious tolerance.

In the play, Saladin, although well-meaning and given to generosity, is flawed precisely in the areas in which Nathan excels. The sultan is bad at chess; Nathan is a master. Nathan is a prudent and rich trader; Saladin, with his ridiculously chivalric contempt for money, is a wretched manager of his household finances. In deep fiscal straits, he goes along with a scheme to extort Nathan by demanding that he prove which of the three monotheisms is the true religion.

To extricate himself from this trap, Nathan the Wise—unlike Nathan the biblical prophet, who criticizes King David—elects instead to charm his ruler and indeed strike up a friendship with him. This he does by means of the ring fable, the play’s central set-piece. An “eastern man,” he relates to Saladin, owned “a ring of priceless worth, received from hands beloved.” The ring bestows upon its bearer the love of man and God alike. Passed down from father to favored son through the generations, it comes at last into the possession of a man with three sons who are all equally dear to him.

Unable to choose, the father causes three copies of the ring to be made, all completely indistinguishable from the original, and distributes them to the sons. They in turn, dissatisfied with this arrangement, appeal to a judge to declare which of them has the true ring. Offering counsel but not a final verdict, the judge urges each to believe his own to be the true ring, and, by means of good deeds, to compete with his brothers in bringing to the fore its magical power. In a “thousand thousand years,” the judge concludes, a wiser man than he will rule on which ring is genuine—if, indeed, any of them is.

Saladin, no doubt stressed by his responsibilities of keeping order in a multi-religious city, is extremely pleased by the answer. The friendship between philosopher and king having been sealed, the stage is set for the happy conclusion. The Templar and Nathan’s adopted daughter Rachel are revealed to be siblings—and, in fact, the children of Saladin’s late lamented brother. Thus is a happy new family created, consisting of both Muslims and Christians. Left unsaid, however, is the fact that Nathan loses his beloved adopted daughter just as surely as if she had married a Christian Templar without his consent.

The implications of Nathan’s ring fable and the drama’s resolution are clear. Adherents of religion should remain loyal to their own faith while working to limit the elements within it that can lead to violent intolerance and conflict. Meanwhile, whatever the established religion, political authorities should accept a basic religious pluralism and refrain from entering into theological disputes. Since, as Nathan says, only God can judge hearts, we must therefore judge men not according to their belief systems but according to their deeds. On these grounds, all those who dwell in the same city can work together in a kind of partnership or even brotherhood.

Yet Lessing is not quite so sanguine as one might think about the prospects of religious tolerance in all circumstances. A hint in this direction is the fact that he set the play “around 1192,” well aware that the historical Saladin died in 1193. To say the least, subsequent rulers would hardly follow their predecessor’s relatively broad-minded approach. The play’s “happy ending” might thus be highly provisional.

The same point holds not only historically but also philosophically. Elsewhere in the drama, Lessing stipulates that religious toleration requires certain important or even decisive changes within the monotheisms themselves. Most important among these changes is a greatly circumscribed belief in miracles. For Lessing, as for Montesquieu and other 18th-century thinkers, good morality requires us to resist the idea that God (or angels) will act on our behalf, and instead accept responsibility for our own fate. “See how far,” he asks his daughter Rachel, “it’s easier to swoon in pious dreams than to do good actions?” Divine morality, yes; divine intervention, no.

When it comes to those “pious dreams,” moreover, Lessing seems especially concerned with tamping down those of Christianity, the one religion of the three that, in Nathan the Wise, looms especially vulnerable to fanaticism and pious cruelty. Precisely because of their faith’s emphasis on purity of conscience, it is incumbent on Christians in particular to turn from judging souls to judging deeds. Today, one might hope that apostles of Lessing-style tolerance would turn a cold eye toward the pious cruelty of certain interpretations of Islam that seek to purify the whole world.

Everyone fortunate enough to live in a liberal political order that has instituted freedom of conscience and religious tolerance owes a debt of gratitude to Lessing and his contemporaries. At the same time, we must admit that religious toleration is not without drawbacks of its own, and in theory may perhaps not be the last word on the subject. I believe Lessing himself was fully aware of the idea’s costs. As Leo Strauss points out in unpublished notes on Nathan the Wise, Lessing’s writings may be read as containing many oblique qualifications of his central thesis.

To take the most significant example, Lessing’s ring fable requires one to believe that religion is like a ring. But isn’t this a woefully partial account of the nature of religion? Is religion really something that, however precious, you can wear or remove at will? In the fable, which Nathan compares with a story told to children, he asserts that the ring has been handed down from “hands beloved.” In other words, he emphasizes its history, its transmission, rather than its origins or creation, if indeed it was created at all. But there is a natural tendency in all religions not to stop at the act of transmission but to inquire and make assertions about sources and origins. In turn, the search for answers to such questions necessarily involves judgments about the content of belief itself—judgments that, for the sake of a political project of religious tolerance, Lessing elides even as he suggests that they cannot be easily ignored.

Finally, Lessing seems to be keenly aware that his doctrine of tolerance would impose costs specifically on Jews. At the end of the drama, as I’ve noted, Nathan is excluded from the new happy family and loses his beloved daughter Rachel. Nor is that cruel social reality the only price exacted of Jews, many of whom to this day, and not least in the United States, eagerly accept one or another version of the parable of the ring. For Judaism does insist on the transmission of “its” ring from one generation to the next—not simply, however, because it has always been so but because of a certain conviction about the Creator and the mission He has entrusted to His chosen people. Indeed, forgetting or ignoring that first principle can significantly dilute the impulse to hand down the tradition itself from one generation to the next. Although bracketing the question of origins may work for individual Jews, it is a move that the Jewish people accepts at its peril.

It would be very hard to deny that religious tolerance has been integral to America. Indeed, the founding fathers started with tolerance but went even further. As George Washington famously wrote to the Jewish congregation at Newport, in America “it is now no more that toleration is spoken of,” as if liberty of conscience were a concession made by one group to another rather than a natural right. The ambiguities and perils of toleration were there, and seen to be there, right from the start of the American project. Lessing helps us to recognize the problem, and its Jewish dimension, in its full complexity.