“Do this in memory of me,” said Jesus at the Last Supper, according to the Gospel of Luke. But memories of Jesus the man have proved stubbornly elusive for historians who are convinced the truth of the son of God lies beneath the surface of Gospel accounts written decades after his death. Now, for the first time, one of America’s most prominent New Testament scholars has gone outside of his narrow field, driven as much by frustration as curiosity, to examine what the science of memory might offer to separate the historical wheat from the theological chaff in the Gospels. In so doing, University of North Carolina religious studies professor Bart Ehrman may have opened a new front in the currently quiescent Jesus wars, a quarter-century of devout and secular scholars battling over what, exactly, is the gospel truth.

Ehrman’s aim was to illuminate the role of memory in crafting the stories of Jesus that would appear in the Bible, and to see how well the assumed role of eyewitnesses in supporting miraculous events stood up. There’s a twist in the tale, though, and frailty of human memory turned out to be more profound than Ehrman suspected or, perhaps, welcomed. His eye-opening Jesus Before the Gospels: How the Earliest Christians Remembered, Changed, and Invented Their Stories of the Savior may prove most useful for those who hold to a position Ehrman finds more wrong-headed than insistence on the Bible’s literal truth. The reason Biblical historians cannot find even the outline of a historical Jesus, argues an increasingly persuasive chorus of challengers, is that there is nothing to find: Jesus Christ never lived at all.

“For the past two years I’ve been reading what I can about memory,” says Ehrman in an interview, “and learning that what we were taught in grad school—what’s still taught in grad school—is untrue.” Changes in oral memory, psychologists, sociologists and anthropologists have found, are actually more radical than in literary transmission, because the literary tends to fix, unchanged, the received text. But every act of oral transmission, Ehrman cites one memory expert as declaring, “is also an act of creation.” That means one of the few pieces of common ground between believers and skeptics—that the oral transmission of stories about Jesus in the time between his death and the composition of the Gospels could be (more or less) trusted—is turning to quicksand.

The crucial gap in written records, lasting four decades or more, between the death of Jesus (which is established today at no later than 36 CE) and the earliest gospel, that of Mark (in scholars’ near-universal view, some time after the fall of Jerusalem in 70 CE), was never a serious issue in New Testament studies. The faithful have always coped with it by assuming that however long it lasted—and they do tend to shorten it—the inerrant Word of God was still passed on in oral form subject to correction by Apostles or other eyewitnesses. Secular historians, without much questioning their own assumptions, accepted the entrenched academic idea that oral cultures were significantly better than literary cultures in preserving accurate memory.

The passage of years explained, in a way acceptable to historians, why there were different accounts of the same event. Ehrman recalls how, as a young professor, he asked an older expert—a proponent of sturdy oral transmission—how he dealt with the fact the gospels give two accounts of Jesus’s visit to the 12-year-old daughter of Jairus: one in which the girl is dying, another in which she is already dead. The answer, that there must have been two visits to the (unlucky) child, was essentially impossible for anyone not committed to gospel truth. Yet at the same time, and of greater importance, historians’ trust in overall oral truth meant small detail changes did not trouble their assumptions about accurate “gist” memories lying at the heart of stories in Mark and the other Gospels.

No more. Memory studies and experiments cited by Ehrman show it would have been impossible to control the contents of stories about Jesus. One experiment a decade ago took 33 university students to a morgue, the sort of experience they would be bound to talk about. Follow-up by the researchers showed that within three days news of the visit had spread in garbled form, via intermediaries, to 881 people. The more often a story is repeated—and a growing new religious community will repeat its stories very often—the more it changes. Repeat one 10 times, as in a game of telephone, and the most salient details—who exactly said what or did what to whom—will change the most. What are the chances, 50 years after the fact, that the author of the Gospel of Matthew remembered hearing the Sermon on the Mount—a polished and nuanced discourse—exactly as it was said?

As for eyewitness corroboration, far from controlling accuracy, eyewitnesses tend to offer the least trustworthy accounts, particularly when recalling something spectacular or fast-moving, like Jesus walking on water. Or thinking that they recall it: 10 months after a cargo plane crashed into an Amsterdam apartment building in 1992, killing 43 people, researchers asked Dutch university students and faculty if they recalled the TV footage of the moment of impact. More than three-quarters said they did, even though there was no such footage. (Not unlike Donald Trump’s crowds of Muslims dancing for joy on New Jersey rooftops on 9/11.) And there’s no reason to believe memories of the more mundane details of Jesus’s life would be any more reliable.

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False memories are easily implanted. Just imagining being at an unusual event—seeing Lazarus rise from the dead, say—can cause a hearer to “remember” being personally present. A group of students in one test Ehrman cites were led, one by one, to a Pepsi machine; half were asked to get down on one knee and propose to it, the other half to imagine doing so. Two weeks later, half of the second cohort remembered actually making the marital offer. Early Christians seemed well aware of the treachery of memory. St. Paul offered assurances to his readers in the Epistle to the Galatians that the teachings he offered had not come to him by an untrustworthy path: “I want you to know, brothers and sisters, that the gospel I preached is not of human origin. I did not receive it from any man, nor was I taught it; rather, I received it by revelation from Jesus Christ.”

Group memory was often the worst, according to anthropologists who watched it distort before their eyes when they recorded several witnesses at once. If a dominant member of the group interjected his version or a new (and potentially suspect) detail, the others would often let it slide unchallenged, incorporating it into the new collective memory. The most important fact about memory, adds Ehrman, is that it’s social as well as individual, “and social memory is all about what matters now.”

That’s why the image of celebrating Muslims on 9/11 comes to the fore in the heat of a xenophobic election campaign, and why the Gospels are full of “recalled” stories that offered guidance on urgent matters at the time they were written down, “arguments with orthodox Jews about keeping Sabbath laws, claims that Jesus had given his disciples powers of healing.” Tales grow in the telling too, while the sort of detail that convinces hearers that “this really happened”—Christ wrote in the dust with his finger before he answered the question about the woman caught in adultery—is precisely what is added to stories, because nothing recommends a tale better than a claim of actuality.

Small wonder then that Ehrman sees the Gospels as rife with “distorted” (that is, false) memories. What is surprising, though, is how much of the Gospels he still thinks he can accept as reasonably accurate “gist” memories, how lightly he applies his new criterion, which he primarily uses as justification for rejecting Gospel stories he long ago dismissed on other historical grounds. Ehrman’s memory book, in effect, is more an appeal to the faithful to accept historians’ approach than a new way of evaluating evidence. His list of what historians, including himself, think they can attest to hardly differs from a list he would have made a decade ago: Jesus was a Jew, an apocalyptic preacher like the man who baptized him, John the Baptist; his teaching, rooted in Torah, was delivered in parables and aphorisms; Jesus had followers who claimed his message was validated by the miracles he wrought; in the last week of his life, Jesus went to Jerusalem, where he caused a disturbance in the Temple that, some hours later, led to his arrest; Pontius Pilate, the Roman governor found him guilty of sedition and had him crucified.

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However appealing and reasonable such a list is to modern skeptics, it is still drawn almost entirely from within the faith tradition, with buttressing by the slimmest of outside supports—brief references from Roman observers. Consider one item on Ehrman’s list, perhaps the most accepted and certainly the one with the largest claim to historical accuracy embedded within it: Pontius Pilate executed Jesus. Scholars are almost universally on-side, as are most Christian churches. Pilate is the sole figure from Jesus’s trial for whom we have undoubted archaeological evidence, and he’s also, perhaps coincidentally, the only one to become part of the Nicene Creed, the most widely embraced capsule statement of Christian faith: “For our sake he was crucified under Pontius Pilate.”

But that wasn’t what all early Christians thought. The apocryphal Gospel of Peter says King Herod signed the death warrant. Others who thought Jesus was nearly 50 when he died believed that happened in the 40s of the first century, long after Pilate had been recalled to Rome. The Nazorians, an intriguing sect of Torah-observant early Christians discussed by a fourth-century scholar, believed Jesus died a century before the canonical Gospels, around 70 BCE. (And, since they were descended directly from the first followers of Christ, called Nazarenes before they became known as Christians, the Nazorians cannot be easily dismissed. The Babylonian Talmud, composed by the fifth century, notes the same.)

Yet Pilate is in Mark as the agent of Jesus’s crucifixion, from which he spread to the other Gospels, and also in the annals of the Roman historian Tacitus and writings by his Jewish counterpart, Josephus. Those objective, non-Christian references make Pilate as sure a thing as ancient historical evidence has to offer, unless—as has been persuasively argued by numerous scholars, including historian Richard Carrier in his recent On the Historicity of Jesus: Why We Might Have Reason For Doubt—both brief passages are interpolations, later forgeries made by zealous Christians.

Snap that slender reed and the scaffolding that supports the Jesus of history—the man who preached the Sermon on the Mount and is an inspiration to millions who do not accept the divine Christ—is wobbling badly. What’s left are the Gospels and the other 23 books of the New Testament, and the so-called apocrypha, Christian books that were not allowed into the Bible when it was finally hammered out in the fourth and fifth centuries. The Gospels are forthright in their agendas to serve theological and not historical needs. Mark may have pinned Jesus’s death on Pilate because he knew or believed it to be true, says Carrier, or he may have been practising “apocalyptic math.”

All over first-century Israel, in an atmosphere of political and religious ferment, Carrier points out, all kinds of groups were doing just that: mining the numerology of the apocalyptic Book of Daniel to determine just when Israel’s liberating Messiah would arrive. Mark’s understanding of Old Testament prophecy may have driven his dating too.

The Gospels show an understandable historical trajectory in themselves. From oldest to newest (John), Pilate becomes steadily less guilty of killing Jesus and “the Jews” more so, reflecting Christian Jews’ growing alienation from other Jews, while the individual Gospels’ messages move from stressing an imminent Second Coming to personal salvation. But their other straight-line development is more in line with what Ehrman’s readings on memory science would predict. Miracles are secret in Mark, known only to the disciples who are forbidden to proclaim them publicly; by John’s time, “signs,” up to raising Lazarus from the dead, are the key to the Lord’s message: only the blind can fail to see he is the Messiah. Jesus’s deeds grow ever more fabulous.

That the Gospels provide only debatable evidence for historians has long obscured the fact that the bulk of the New Testament, its epistles, provide none at all. The seven genuine letters of St. Paul, older than the oldest Gospel and written by the single most important missionary in Christian history, add up to about 20,000 words. The letters mention Jesus, by name or title, over 300 times, but none of them say anything about his life; nothing about his ministry, his trial, his miracles, his sufferings. Paul never uses an example from Jesus’s sayings or deeds to illustrate a point or add gravitas to his advice—and the epistles are all about how to establish, govern and adjudicate disputes within Christianity’s nascent churches. And, despite knowing the apostles Peter, James and John, he never settles a dispute by saying, “Peter, who was there at the time, told me Jesus said this . . . ” Nor, by the evidence of his correspondence, did any faraway Christian ever ask Paul about Jesus’s life. Everything the Apostle claims to know about Jesus comes from his reading of the hidden messages in Old Testament passages and by direct revelation, the latter being the very thing that proves its worth, as he told the Galatians.

Carrier’s book on the case for Christ as a mythical construct rather than an actual human being is something of a breakthrough on the mythicist front. He gives credit to earlier writers, especially Canadian Earl Doherty, but Carrier’s rigorously argued discussion—made all the more compelling for the way it bends over backwards to give the historicist case an even chance—is the first peer-reviewed historical work on mythicism. He’s relatively restrained in his summation of the absences in Paul’s letters. “That’s all simply bizarre. And bizarre means unexpected, which means infrequent, which means improbable.” Historicists have no real response to it. Ehrman simply says, “It’s hard to know what to make of Paul’s non-interest; perhaps he just doesn’t care about Jesus before his resurrection.” Other historians extend that lack-of-curiosity explanation to early Christians in general, which is not only contrary to the usual pattern of human nature, but seems to condemn the Gospels as fiction: if Christians couldn’t have cared less about the details of Jesus’s life and ministry, they wouldn’t have preserved them, and the evangelists would have been forced to make up everything.

Paul is a puzzle for historicists because they are committed to the reality of Jesus, a commitment that’s a result of their own social memories, as far as Carrier is concerned. “If this was Osiris we were talking about,” he says in reference to the Egyptian god who displays close parallels to Jesus in his life, death and resurrection, “most historians would have moved to the mythicist position long ago.” But Jesus Christ is sunk deep in the Western world’s psychic and cultural DNA; viewing the Gospel as a mix of fact and metaphor is perfectly acceptable in a post-religious world, but outright rejection isn’t, not least for those whose careers depend upon the former. Modern Christians can smile at the extra-Biblical accounts of Jesus’s wonder-working, like his taming of two dragons in the Protoevangelium of James, and know it as myth, says Ehrman, but they scarcely notice the contradictions between the Gospels. And they find the recasting of those Gospels as complete myth deeply troubling.

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Ehrman flicks at that reality when he expresses his regret that some people have responded to his pruning of ahistorical elements from the Gospels with a “Well, if that’s not true, I guess none of it is, and none of it matters.” “I don’t know why people feel that way,” he says. “For me Gospel stories are hugely important, whether they’re factual or not.” And so they are, to the history of Christianity and Western culture in general, but not to the history of Jesus, as Ehrman’s own foray into memory study demonstrates: Biographical details, the assurance of physical actuality, are the greatest missionary tools.

Attitudes like Ehrman’s are what stop most historians from really weighing the implications of what evidence there is, says Carrier, and, even more so, the evidence that should be there but isn’t. For a century there are no other Christian witnesses; perhaps more inexplicably, no pagan witnesses (whose references to Jesus would have been mentioned by later Christians, either to celebrate or refute); the new faith’s most prominent Apostle seems only to know a cosmic Christ, about whom he has learned by vision and close reading of the prophets; the first adherents can’t agree, within a century, when their founder died or who killed him. It is much easier, Carrier sardonically points out, to have those kinds of disagreements about a non-existent person, for whom there are no relatives or friends to gainsay the results.

The mythicist answer to all this is far more logical, according to Carrier, a solution that requires no special pleading. His take on Christianity’s origins begins in the religiously roiling Israel of the 30s, when the restive population was starting to rebel against the Temple elite. The cultic practices, mostly involving animal sacrifice, on the Temple Mount were central to national existence, “the Jewish people’s conduit to God and eventual salvation,” Carrier says. “That meant money flowed into the Temple and power flowed out, and all kinds of fringe Tea Party-type groups reacted to that, coming to believe defilers ruled over them. Some groups we know of, like the Zealots, were violent but in a hopeless position against the Roman legions, so there was bound to be a spiritual response too.” Through visions, apocalyptic math and study of the Scriptures, one group—headed, according to the evidence of Paul, by Peter—came up with a celestial being made human flesh, killed by the forces of evil in a sacrifice that combined and eclipsed both Yom Kippur and Passover, who rose from the dead and will very soon come again to save the faithful.

Soon enough, as the tendencies of human memory predict, the cosmic Christ, like central figures in other contemporary mystery cults, was “factualized” to better attract adherents. Again, given the way social memory is really all about the problems of now, the Gospels display their interest in issues liable to confront any missionary: prophets without honour in their own lands (that is, treated skeptically in their villages, where people remember them); faith healings that don’t always work out (it’s the fault of those who lack faith); why your allegiance should be to your faith family, not your biological kin (Jesus pushed away his own siblings).

Carrier’s account, logical as it is, sounds as bizarre as Paul’s disinterest in a real Jesus. The author realizes that, and he makes no claim to having proved it or disproving the Gospels—merely that his scenario fits the facts without distortion and the Gospels’ history is awfully hard to prove. Ehrman is aware of that, and aware too that he has not helped historians’ cause with his memory work. He’s reluctant to talk much about the mythicists, much less debate with them, although he does have one such event coming up in the fall. But he acknowledges, “they’re making headway now, among atheists and agnostics.” And if their case started to be ascendant among Christians, “it would be a blow.”