What would the Jews look like had they not been exiled to the four corners of the earth, had they gone untainted—but also unenriched—by the cultures in which they tarried? Imagine Jews who retained their fierce attachment to the Torah and the faith of their fathers, but without the rabbinic response to displacement. No Talmud, no golden flourishing diasporas in Spain or Germany or America, no great movement out of the ghetto and into the Haskala, none of the upheavals of modernity, no Reform movement, no Holocaust, no Zionism, no state of their own, no Nobel laureates to kvell over, only the steady drip of obscurity, anachronism, and numerical decline. What would those Jews be like today?The answer revealed itself to me the other day atop Mt. Gerizim overlooking the city of Shechem, otherwise known as Nablus, where the High Priest Aharon Ben-Av Hisda, 83, 132nd holder of the post since Aharon, the brother of Moses, was presiding over the Passover sacrifice. He wore a white beard, a loose green silk robe tied at the waist with a wide cloth, and a blue-striped tallit draped over his head. Rising above the jostling assembly of his entire people, which numbered fewer than 750 souls, he clutched a chest-high wooden staff, worn smooth with age, in his left hand. He stood on a small platform facing priests bedecked in white turbans and elders outfitted in red tarbooshes wrapped with a gold and white sash. As the sun set to unveil a full moon, Hisda’s chants (ancient Hebrew and Aramaic comingling in his throat) crescendoed, and with an ecstatic cry the sacrifice rites commenced.All at once, dozens of white-robed Samaritan men, descendants of the ancient northern Kingdom of Israel, sliced their knives into the throats of the lambs—one per family—which in accordance with biblical instruction had been purchased four days earlier (Exodus 12:3-12:4) and had been coaxed to the sides of a long altar. Hisda’s congregation dipped their fingers into the warm, newly shed blood, dabbed it onto their foreheads, and embraced one another with joy. The slaughtered animals were skinned and disemboweled with expert haste, skewered on 10-foot spits, and placed in fire-pits gaping in the ground nearby, there to be roasted until the midnight feast commemorating the Exodus from Egypt.Samaritans are the smallest religious group in the holy land, and probably the most ancient. Best known for their cameo role in the most famous of New Testament parables, the story of the Good Samaritan, they offer modern Jews a glimpse into our own past. Indeed their ceremonies prove impossible to witness without the jarring chronological blur that comes from a disruption in the historical continuum. They are our ancestors come to life—except they are not. The most faithful followers of the Torah, it seems, may not be Jewish at all.Samaritan faith is monotheism at its simplest: a belief in one God, the God of Israel (whom they call “Shema,” or “the Name”); one prophet, Moses; and one Torah. Anything outside the five books—later prophets, oral law, rabbinic interpretation—is alien to them. There is neither Purim nor Hanukkah, no bar mitzvah, no requirement of a minyan (a quorum of 10 men) for prayer. On the other hand, Samaritans enforce strict observance of the Bible’s laws of ritual impurity (menstruating women are separated from their husbands for seven days) and the Sabbath (no traveling, cooking, writing, or sex).Passover, celebrated this year a month after the tamer Jewish version, is far from the only sign that religious habits that for Jews have receded into a symbolic representation of an ancient memory—the burnt shank bone on a seder plate that represents the paschal sacrifice—remain for the Samaritans a living practice. Take the way this tiny community organizes itself according to religious hierarchy. Unlike the Jewish priesthood, which faded after the destruction of the temple in Jerusalem in the year 70, Hisda and his fellow priests still serve as unquestioned decision-makers, interpreters of the law, and keepers of the calendar (an abstruse art they call by its Aramaic name “Ishban Kashta,” or “truth calculation”).In another sense, however, the Samaritans present to Jews not so much a primeval past as an alternate vision of themselves, a road not taken.The divergence, the fork in the road, began here on Mt. Gerizim above Nablus, where Samaritans have lived and worshiped since the day Joshua brought the holy ark here and offered the first sacrifice in Canaan (Deut. 27:4). Hisda and his community, which broke away from mainstream Judaism more than two and a half millennia ago, venerate Mt. Gerizim as the center of Samaritan sacred geography. Samaritans face Gerizim when then pray. It is where Adam was fashioned of the dust of the earth, where Noah built his altar after the flood subsided, Jacob dreamt of the angel-ladder, Abraham offered up his son Isaac, and Joshua placed the 12 stones he had brought from the Jordan when the Israelites entered the land of Canaan. (The Samaritan calendar counts from the year Joshua crossed the Jordan into the land of Canaan: the year 2794 on the Jewish calendar, which counts from creation.) This spot went by various biblical names, Samaritans say: Bethel (Gen. 12:8), House of God (Gen. 28:17), Luz (Gen. 28:19), the Chosen Place (Deut. 12:11), and the Everlasting Hill (Deut. 33:15).The Samaritans believe that Mt. Gerizim, and not Jerusalem, is the real Moriah. They insist that the legitimate line of high priests, from the family of Eleazar, remained on Gerizim; the false line, from the family of Itamar, stole the ark to Shiloh and thence to Jerusalem. When the Jews made Jerusalem, some 40 miles to the south, the exclusive center of worship—a chosen city for a chosen people—the Samaritans regarded the Jewish cult as illegitimate.This initiated the ancient “temple race” between the Samaritans and the Jerusalem-centric Jews whose beliefs and history shaped modern Jewry. By permission of Alexander the Great, the Samaritans built a temple of their own, measuring 400 by 560 feet, atop Gerizim. In use for some 200 years, the temple was destroyed before the first century BCE, never to be rebuilt. Israeli archaeologist Yitzhak Magen, who supervised the digs on Gerizim, has found coins and inscriptions dating back 2,200-2,600 years.The Bible recounts that when Ezra and Nehemiah rebuilt Jerusalem and its temple, the Samaritans tried to prevent them; Sanballat, then leader of the Samaritans, mocked “these feeble Jews” (Neh. 4:2). The 1st-century Jewish historian Josephus reports on Samaritans who intruded into the temple in Jerusalem one Passover eve and scattered human bones to render the place unclean. The Samaritan Chronicle boasts of another episode in which Samaritans substituted rats in a cage of doves being carried to Jerusalem as temple offerings.The antipathy ran both ways. Among Jews threatened by a rival to Jerusalem’s claim of exclusivity, a deep anti-Samaritanism prevailed. This culminated in a rabbinic ruling by Rabbi Yehuda Ha-Nasi that, despite their scrupulousness in the observance of biblical law, the Samaritans were to be considered as Gentiles in every respect.Yet the rival temples and the rival communities, each claiming to be true heirs of the Mosaic tradition, were fated to share a common experience of persecution. Like the Jews, Samaritans were massacred by the Romans. Hadrian built a pagan temple on Gerizim, torched Samaritan scrolls, and forbade Samaritans to perform circumcisions. Early Christians forcibly converted Samaritans and in the 5th century expelled them from Gerizim and built a church to Mary on the site. Later, Muslim rulers forbade them from praying or bringing the Passover sacrifice on Mt. Gerizim, a ban that lasted until 1820.Despite the persecutions, most Samaritans remained in nearby Shechem (some 300,000 by the end of the 2nd century), with vibrant communities also in Gaza, Ashkelon, Beth Shean, Caesarea, and Yavneh. As of the 5th century, they numbered well over a million. It is true that starting in the 2nd century, a small Samaritan diaspora spread to Egypt, Greece, North Africa, Italy, and Sicily, but this was a peripheral, short-lived affair, limited by the mandate incumbent on every Samaritan to make the pilgrimage to Gerizim three times a year.Over the subsequent centuries, a precipitous decline set in. By the 17th century, the number of Samaritans in the world had dropped to 140, where it more or less remained through World War I. Birth defects became common. In 1867, Mark Twain encountered in Shechem a “sad, proud remnant of a once mighty community” that had dwindled to near extinction. “I found myself staring at any straggling scion of this strange race with a riveted fascination,” he wrote in The Innocents Abroad, “just as one would stare at a living mastodon.”The resurgence of the Samaritan community owes something to the establishment of the modern State of Israel, whose second president, Yitzchak Ben-Zvi, encouraged Samaritan priests to allow the community’s men to marry Jewish women who committed to Samaritan observances (Samaritans, unlike Jews, rely on patrilineal descent). Their numbers rebounded: 350 in the early 1960s, 500 by the late 1970s. Today, the community counts 730 Samaritans, divided into four extended families: Cohen, Tsedaka, Danfi, and Marhib.This Passover, I was hosted by Benyamim Tsedaka, founding editor of the biweekly Samaritan newspaper, A.B., for Aleph Bet. Tsedaka’s wife Miriam, an Israeli from Nahariyah, married into the community in 1969, and his grandmother, a Russian Jew, was the first woman to marry in.Another of his guests that evening was the first woman to join the Samaritans on her own, not by marriage. Sharon Sullivan, an earnest graduate student at Hebrew University from a family of lapsed Catholics in Michigan, moved to Israel a year ago. It was the Samaritans’ sense of fidelity to the Torah, without the rabbinic frills, that attracted her, she said. Today Sullivan is part of a team led by Jim Ridolfo of the University of Cincinnati, which was awarded National Endowment for the Humanities funds to create an online archive of Samaritan texts (including three 15th-century Pentateuchs), scrolls, and artifacts housed in the E.K. Warren collection at Michigan State University.It is not uncommon to find a Samaritan family that has been in continuous possession of a Torah codex for 600 years. Each generation adds a layer of fine colored cloth, and on Passover or other special occasion, when the current trustees show the venerable volume to a guest, they must peel back layer upon layer. This Passover I wondered whether there is in that gesture, magnificent in its modest way, both a reminder of the quality of timelessness, of eternal recurrence, that characterizes the Samaritans and a hint of what, for better and for worse, the Jews might have become.Today, the Samaritans are split in two. Half, including the new convert Sullivan, live in Holon, near Tel Aviv, home to a Samaritan community since the 1950s. The other half live in the village of Luza atop Mt. Gerizim in the West Bank on land purchased for them by King Hussein of Jordan. (Another gift, oddly enough, came from the Vatican. Pope John Paul II donated $190,000 to help build a Samaritan school here.) Luza now shares the mountain with the Jewish settlement of Brakhah (population 1,400).During the Jordanian occupation of the West Bank, Holon Samaritans were permitted to visit Gerizim only once a year, on Passover. The Six-Day War opened the borders between the two, but of necessity, the community has long practice with the intricate choreography of neutrality in the Israeli-Palestinian conflict. This is nothing new. The 1st-century Jewish historian Josephus accused the Samaritans of playing both sides: “they alter their attitude according to circumstance and, when they see the Jews prospering, call them their kinsmen, on the ground that they are descended from Joseph and are related to them through their origin from him, but when they see the Jews in trouble, they say that they have nothing whatever in common with them nor do these have any claim of friendship or race.”These days, Samaritans use both a Jewish and an Arab name; most are fluent in Hebrew and Arabic. They seek good relations with the Arabs in Nablus and send their children to the city’s An-Najah University. The late Palestinian President Yasser Arafat honored their loyalty by appointing a Samaritan to the 88-seat Palestinian Legislative Council. On the other hand, the Holon Samaritans, full Israeli citizens since the earliest days of the state, are fully integrated into Israeli life and serve in the IDF. (Nablus Samaritans like Tsedaka were granted Israeli passports in the mid-1990s.)And so the delicate dance, set into motion by the dependence of this improbable remnant of an ancient people on its more powerful and more numerous neighbors, continues.