A rake seduces women and murders their male relatives with impunity until the statue of one of his victims invites him to supper and drags him to hell. It sounds silly, but for two centuries it was the most-favored plot device in Western literature. Don Juan was the invention of Tirso de Molina, a Spanish monk from a family of converted Jews. Concealed in its puppet-theater plot is a Jewish joke: Don Juan exists to prove by construction that a devout Christian can be a sociopath, and by extension, that the Christian world can be ruled by sociopaths. The Enlightenment’s most insidious attack on Catholic faith, then, came not from atheists like Voltaire, but from a Spanish monk with buried Jewish sensibilities.A century and a half later, another converted Jew—Emmanuele Conegliano, known as Lorenzo da Ponte—reworked Tirso’s play as a libretto for Wolfgang Amadeus Mozart, and the result was an utterly unique work of art. It is pointless to argue about whether Don Giovanni is the best opera ever written, because it is a genre unto itself—the musical tragi-comedy, or “drama giocoso,” as Da Ponte put it. Mozart’s combination of tragic and comic elements turns the world inside out. From the first bars of the orchestra to the final note, we are unsure whether we should laugh, cry, or feel fear. If you don’t leave the theater confused, you haven’t been listening.Mozart’s anti-hero seduced 2,065 women, his servant Leporello recounts in the celebrated Catalogue Aria. As a literary archetype, Don Juan’s conquests are just as prolific. One scholar lists 1,720 published variants on the theme since Tirso de Molina printed The Trickster of Seville in 1630, in the middle of the Thirty Years War. For the two centuries between Tirso and Byron’s eponymous epic poem, Don Juan bestrode the literary imagination like no other personage in history.In a post-Christian world that has lost interest in the problem of sin and salvation, Don Juan is passé. By 1821, when Juan appears in Byron’s eponymous masterwork, Juan was on his farewell tour. E.T.A. Hoffman’s and Kierkegaard’s fascination with the subject is a response to Mozart’s astonishing music, not to the literary theme. Baudelaire’s poem “Don Juan in Hell” and Shaw’s intermezzo of the same title make Juan into a defiant hero. Desultory efforts to recast Don Juan as a Freudian case history still crop up from time to time, but lack conviction and much of an audience.Juan held the audience of the 17th and 18th centuries in thrall, because he personified the Christian world’s foreboding about its own vulnerability. Tirso’s trickster poses an impossible paradox for the Christian concept of salvation: The story is not about eros, but evil. Christian society is founded on the premise that it requires “only one precept,” as St. Augustine put it: “Love, and do as you will.” Once humankind accepts the utterly unselfish love of Jesus Christ, Christianity asserts, the elaborate body of Jewish law becomes redundant, for Christian love will elicit the right behavior spontaneously.The trouble, Tirso demonstrates, is that society that depends on conscience has no defense against a sociopath who has none. Don Juan is a predator inside the Christian world with no natural enemies. Juan enjoys murdering the male relatives of his female victims almost as much he enjoys seducing the women. To the extent that we can speak of Juan’s descendants in today’s fiction, they are not so much lovers but serial killers.Tirso’s theological mousetrap had more than hypothetical importance for the audience of 1630, a dozen years into the Thirty Years War that would ruin the Spanish Empire and kill not quite half of central Europe’s population. His world was infested with sociopaths in positions of power, including Spain’s King Philip IV, one of whose bastards would eventually stage a coup against the legitimate heir to the Spanish throne. Philip makes an appearance in The Trickster of Seville, lightly disguised as the 14th-century king Alfonso XI, who also peopled the Spanish royal line with bastards.It may not be a coincidence that Alfonso’s bastard son, Henry of Trastámara, incited Jew-hatred to overthrow his more tolerant half-brother, the legitimate heir Pedro I of Castile. Henry led the massacre of 12,000 Spanish Jews in Toledo on May 7, 1335. The Jews fought alongside Pedro in a prolonged civil war and suffered horribly after Henry won and beheaded his brother with the words: “Where is that son-of-a-whore Jew?”We forget such things today, but in Tirso’s lifetime they were burned into living memory. Nearly a quarter of a million Jews lived in Spain in 1492, a tenth of the country’s population; given the choice of exile or baptism in that year, more than half chose to leave, but tens of thousands died en route. Jews dominated Spain’s literary elite, and those who stayed produced a disproportionate number of Spain’s writers in the Golden Age of the early 17th century, Tirso included. But the “new Christians” never fit in. To this day, families in Toledo distinguish between “new” and “old” Christians.Tirso drives the paradox still deeper. The original Don Juan of the Spanish Golden Age is a believing Catholic, who has no doubt that repentance and forgiveness through the Church can save his soul: For that reason he can devote his youth to evil and repent sometime later. “You’re giving me plenty of time to pay up!” (“que largo me lo fíais”), he mocks whomever urges him to repent and save his soul. (A variant of The Trickster of Seville was published under the title Que largo me fíais, making clear that the play hinges on Juan’s twisted but orthodox theology).Juan’s servant Catalinón (Leporello in Mozart) warns him that even a long life is short, and sin will be punished. “If you give me so much time to pay up,” Juan replies brightly, “let the tricks continue!” Besides, he adds, his father is the king’s favorite. Christianity, as Tirso observes, can produce a monster who does nothing but evil precisely because he believes in heaven, hell, and the sacraments of the Church. Tirso might have had Kohelet 8:11 in mind: “Because the sentence against an evil work is not executed speedily, therefore the heart of the sons of men is fully set in them to do evil.” But Christian reliance on the Attribute of Mercy at the expense of the Attribute of Justice, as the theologian Michael Wyschogrod put it, frees Juan to formulate a sociopath’s theory of salvation.That, incidentally, explains why modern-dress versions of Mozart’s opera fail so miserably. In today’s epoch of the hook-up, a serial seducer is not a monster, but only an annoyance. No one gets dragged down to hell anymore. Juan’s natural habitat is the twilight of faith, the point at which the Catholic world fought with the presentiment of its decline but held on all the more intently to its faith.Tirso’s critique of Christianity follows the rabbinic reading. As the Rav Joseph Dov Solovietchik put it, “Subjective faith, lacking commands and laws, faith of the sort that Saul of Tarsus spoke about—even if it dresses itself up as the love of God and man—cannot stand fast if it contains no explicit commands to do good deeds, to fulfill specific commandments not always approved by rationality and culture.” In Don Juan, the Christian world saw its own susceptibility to chaos. That is why the European audience could not take its eyes off him for 200 years.No writer portrayed this chaos and its theological sources more vividly than Tirso. The usual account of Don Juan and his 1,719 literary imitations reduces Tirso’s brilliant and complex play to a simple-minded morality lesson. Christian critics do not seem to grasp how great and enduring was the pain of the Spanish Jews; even worse, they evince a deaf ear for Jewish irony. “The Trickster” is a Jewish joke, and the critics don’t get it. The theologian David Bentley Hart, for example, wrote recently that “Juan was the greatest immoralist of European literature precisely because he served as the negative image of the moral convictions and capacities of his time and place, the exemplary contradiction of an entire and coherent vision of the good, whose story magically combined a certain nostalgia for fading cultural certitudes with a certain cynicism toward them.”In fact, “The Trickster” is a Jewish practical joke of cosmic malevolence, a burlesque de profundis, a bitter laugh from the depths. I found a translation of Tirso in the public library 45 years ago, after learning of Da Ponte’s source from the liner notes in a recording of Mozart’s opera. Don Giovanni knocked me sideways as a 14-year-old. My secular home didn’t have a chumash. But Mozart’s opera stirred something in me, an awareness, perhaps, of the woeful inadequacy of the enlightened reading of the human condition. I saw every performance I could, pounded out the piano score, and scoured the literary sources for the libretto. Not until recently did it occur to me that between the notes, I was hearing the muffled anguish of the Spanish Jews.The theme appealed to Mozart, whose musical genius uniquely enabled him to balance tragedy with raucous good humor. Just before the statue arrives at Giovanni’s palace, one of his rejected conquests, Donna Elvira, bursts in to beg him to change his evil ways. Giovanni mocks her, toasting women and good wine; Elvira pathetically tells him to stop; and Leporello mutters to himself comically that his master has a heart of stone. Except they are all doing this at the same time, in a trio in which each of three vocal lines contains a perfect characterization of the three contrasting emotions. There is nothing quite like this in all of opera.Elvira departs, and we hear her scream off-stage. There is a knock at the door. Leporello answers it and warns his master in Lou Costello style, “Don’t go that way! There’s a man of stone! He’s going, ‘Ta, Ta, Ta’!” Giovanni ignores him. The statue (whom Giovanni had mockingly invited to supper in the previous scene) tells Giovanni that he must accept a return invitation. “Sorry, sorry, he has a previous engagement,” Leporello interrupts. We are deep into Mozart’s most tragic D minor, but even then the jokes keep coming.Giovanni is dragged down to hell, and the rest of the cast appears to find that divine justice has done for their tormentor. Nobles, bourgeois, and peasants sing, “That’s the end of those who do ill!” and Da Ponte makes us understand that they are the same credulous fools whom Giovanni duped before.We laugh at the assemblage of Giovanni’s victims: the domineering and bitter Donna Anna and her feckless fiancé Ottavio; the pathetically devoted Donna Elvira; the social-climbing peasant girl Zerlina and her doltish intended Masetto; and the cowardly, conniving servant Leporello. There is no question, though, that Mozart has written a tragedy—not Don Giovanni’s, but ours. Mozart’s best music is reserved for the human cost of Giovanni’s depredations. At the crux of the opera, Donna Anna suddenly recognizes Giovanni as the masked intruder who attempted to rape her (and possibly succeeded) and then killed her beloved father. A long dramatic recitative prepares Anna’s vengeance aria, “Or sai chi l’onore,” with Mozart’s tonal transformation mirroring Anna’s progression from recognition to fear and then to resolve. The dean of American music theorists, Carl Schachter, has published the authoritative analysis of this almost miraculous passage.The supernatural resolution of the matter is a masterstroke of Brechtian alienation, a flamboyantly buffo set of sight gags, so at odds with the seriousness of the situation that it sets in relief the absurdity of the premise. If a supernatural intervention that silly is the only thing that will get rid of Don Juan, the not-so-subtle message is that Christendom is incapable of ridding itself of evil through its own efforts.How did Tirso get away with this lampoon of Catholic soteriology? The apparent answer is that the Spanish Church was distracted by the Protestant menace. John Calvin proposed to solve the paradox of salvation by arguing that only a predestined elect would be saved. Don Juan is no Calvinist; he believes that his will is free to choose salvation, whenever he feels like it. The Inquisition checked the “free will” box and gave Tirso a pass. We may have no choice but to believe in free will, as Isaac Bashevis Singer joked, but Calvin’s concept of election lies closer to the Jewish point of view. Its logical consequence was to remove the elect from a world governed by sociopaths to a New Israel, namely America.Tirso drew on folk tales in which a living person invites a dead man to dinner and perishes when the invitation is returned. But Juan is not an archetype of legend: He is a metaphysical construct unique to his time, and to the tragedy of the Spanish Jews. Don Juan has only one great antecedent in literature, in fact an ancestress, the procuress Celestina, the anti-heroine of Fernando de Rojas’ 1499 tragicomedy. Printed just seven years after the expulsion of the Jews from Spain by a converso attorney who represented his father-in-law before the Inquisition Court, De Rojas’ tragicomedy is a howl at heaven, a malediction on Christian Spain.Whore and harpy, Celestina is perhaps the most frightful character ever to walk the Western stage. She is oblivious to danger and brilliantly manipulative. Next to her, Marlowe’s Barnabas and Shakespeare’s Iago, or even Goethe’s Mephistopheles, are mischievous schoolboys. Hired to help a young man seduce the socially superior girl he desires, Celestina sets events in motion that cause the death of the entire cast. As a genre, tragicomedy has its roots in antiquity—Plautus was the first to use the term—but in the modern world, the juxtaposition of bathetic and horrific elements begins with De Rojas’ gallows humor under the shadow of the Inquisition.Celestina (the “Tragicomedy of Calixto and Melibea”) became the first blockbuster best-seller in Western literary history. By 1620 it had been performed in English; a full English translation was printed in 1631. Shakespeare and Marlowe drew on it. There are scenes in the drama whose grotesque humor no English dramatist has surpassed. It went through 30 Spanish editions during the 16th century alone, as well as translations into the major European languages, not to mention a 1505 Hebrew version of which only a few lines survive.De Rojas’ procuress is a hellion who calls on the devil for help. Tirso’s Don Juan is more insidious. Don Juan is neither heretic nor hypocrite: He is a devout believer who has figured out that the system entitles him to be thoroughly evil for the interim. His existence points up the hypocrisy around him; because the Christian world cannot deal with this monster, it must accommodate him. Both Celestina and Don Juan haunted the literary imagination with the same subliminal message: Your world is badly made, and it will come to a horrible end.Tirso de Molino wrote for a world where sociopaths wore the garb of nobility and clergy. The dueling masterminds of the Thirty Years War, Cardinal Richelieu and the Spanish Prime Minister Olivares, each believed that his country was divinely selected for God’s service and therefore could commit unspeakable acts on behalf of its national ambitions. But a new kind of sociopath was about to step on the world stage, and Mozart warns us of his approach. At the end of the opera’s first act, Don Giovanni welcomes a group of maskers to his palace (they are Anna, Elvira, and Ottavio in disguise). Da Ponte has Giovanni declare, “It’s open to everyone. Long live liberty!” Mozart does something unexpected: The whole cast breaks character and in martial fanfare sings “Viva la libertà!” Lurking behind the mask of liberty in the enlightened world was a capacity for evil perhaps greater than anything the traditional world had brought forward. This was in 1786, three years before the French Revolution. How did Mozart know?David P. Goldman, Tablet Magazine’s classical music critic, is the Spengler columnist for Asia Times Online, Senior Fellow at the London Center for Policy Studies, and the author of How Civilizations Die (and Why Islam Is Dying, Too).