Here is the description I gave of that criterion from my 2016 book, Jesus is No Myth: The Fingerprints of God on the Gospels. This is the whole of Chapter Eight. You can find Wright's original discussion in Jesus and the Victory of God.
Chapter Eight: Double Similarity, Double Dissimilarity
Big events do mold us, but aside from death (and then we shall see), after the initial wave passes, life usually regains equilibrium.
You marry. A year later, you are blessed with a child.
What has changed? In a way, everything. Not long before, you cooked instant noodles over a Benson Burner, let moss colonize the grease on top of the stove, and scoffed with contemptuous detachment at mismatched socks. Then you met that special person. You put on your best, learned fine dining or a “great burger joint,” watched your table manners, and stopped wearing old t-shirts, and used them to dust the furniture. Your face lit up when your lover said “You look nice!” because within the sphere of her luminosity, you did. The two of you found no end of things to talk about. Her aura stayed with you when you lay on your back at night, stared with a sigh at the ceiling, and fell to sleep amid pleasant dreams.
Then she grew about the waist, and your mutual dreams grew, too. Shopping became a mission from God. Giving birth was literally an out-of-body experience. You became “father” and “mother” - words from a myth or ancient prophecy, mysteriously applied now to you. You were the first creatures visited by this miracle: Adam and Eve in Eden, Christopher Atkins and Brook Shields in The Blue Lagoon. The planet rotated to a new theme song. Sun, moon and stars bowed down to the infant in the crib. King Baby became your sovereign, love, entertainment system, (broken) alarm clock or crazed rooster that heralded the new day while the sun lazily rested in remote firmaments of the sky on the far side of the Earth.
So many changes! But far out at sea, the boat slowly rights from tsunamis that pass under its keel. Most of your brain cells remain in place, however reluctantly they clock in. Once distended and quirky, your stomach reasserts old cravings.
So there is double discontinuity in marriage and childbirth. Wedded life is not the same as singleness, and being a parent is not the same as remaining childless. The content of your Facebook pages from these two periods distinguishes them from the rest of your life. Yet there is also a double continuity. The two of you are still “Robert” and “Rebecca” or “Miles” and “Manny,” children of unique parents, moved by Swan Lake or Taylor Swift, with freckles and memories of secret love and childish adventures.
Jesus had an impact upon his disciples like the founding of a new family, or the landing of a shooting star on a desert floor. The impact of that life left a crater - like the sudden mixing of meteorite and native sod - impressions, sayings, acts flung into the pages of the earliest records, that distinguish those records from what came before or after.
Probably the greatest modern English historian of early Christianity, N. T. Wright, has developed a powerful argument for the gospels from this blend of old and new. Wright taught New Testament at Oxford and Cambridge Universities. He is author of an epic series on “Christian Origins and the Question of God” that is erudite, lucid, and informed as are few works in the field. Jesus Seminar fellow Marcus Borg described Wright as “the leading British Jesus scholar of his generation.” In The Elusive Messiah: A Philosophical Overview of the Quest for the Historical Jesus, philosopher Raymond Martin placed Wright at the forefront of scholars studying the historical Jesus, praising his methodology as unmatched in sophistication.
In light of the problems we have encountered with methodologies for evaluating the gospels, perhaps we can gain from Wright’s perspective.
Israel and the Prodigal Son
In Jesus and the Victory of God, Wright introduces the argument from “Double Similarity, Double Dissimilarity” by retelling Jesus’ story of the Prodigal Son.
Jesus told this story in Luke 15, in partial response to complaints from unnamed Jewish leaders about the company he kept. “Why is Jesus eating with sinners?” This was a natural question, in a religious culture in which the need for holiness meant setting oneself apart from the world. Aslan was wrong to reduce Jewish tradition to withdrawal from the Gentile world’s impurities, but he was right to recognize that as a central element in the tradition, especially pressing in occupied Palestine. Jesus told three parables to answer his critics’ challenge: about a lost sheep, coin, and son. A man secured 99 sheep in the pen to search for one lost on the mountains. A woman found her lost savings, and called friends over to celebrate. In both cases, the moral was essentially the same: God rejoices when what has been lost, the “sinner,” is redeemed and brought home, which by implication is what Jesus came to do, “seek and save that which has been lost.”
Jesus’ third story is by far the longest and most famous, and is an arrow aimed at the caricature of Jewish tradition Aslan perpetrates and to which he seeks to reduce it. A father had two sons. The younger tired of working for his father and requested an early inheritance check. In the context of time and culture, this request must have come as a rude slap in the face to the father: as Wright puts it, it was like saying “I wish you were dead.” But the father, whom Wright recognizes as the hero of the drama, graciously granted his son’s outrageous demand. The son took “his portion” of the family wealth and ran. In a distant land, he used up those funds, and was reduced to hiring himself out to a Gentile to watch pigs: lower than a beetle’s knees, in Jewish thinking. Then the thought crossed his mind: “If only I could work as one of my father’s servants! They are at least decently fed!” (Reminding Jesus’ hearers what kind of man the father was.) So the lad straggled home, preparing a properly apologetic speech as he trudged along. But before he reached the estate his father, ignoring the stoic proprieties placed upon the pater familius in Jewish and Roman cultures, ran down the road and embraced his lost son.
To this point, as with the stories of the sheep and the coin, Jesus was simply answering his critic’s question: “Why are you spending time with these miserable sinners?” He answered them in the context of Jewish history. As Wright explains, “This is the story of Israel, in particular of exile and restoration. It corresponds more or less exactly to the narrative grammar which underlies the exilic prophets, and the books of Ezra and Nehemiah, and a good deal of subsequent Jewish literature.“ But then the redemptive story Jesus was telling, and the knife, took a twist, as Wright notes: “For there is a second son, an older lad, and he represents the people who asked Jesus this question.”
And with that twist, Jesus’ judges somehow found themselves in the defendant’s seat:
“This is an explosive narrative, designed to blow apart the normal first-century reading of Jewish history and to replace it . . . this tale subverts the telling of the story which one might expect from mainstream first-century Jews . . . “ (126)
What Jewish story is Jesus challenging? Israel was defined first by its captivities to Egypt and Babylon, and as fragments of Greek and Roman Empires, then by promises of return and reconciliation with God:
“Exile and restoration: this is the central drama that Israel believed herself to be acting out. And the story of the prodigal says, quite simply: this hope is now being fulfilled - but it does not look like what was expected. Israel went into exile because of her own folly and disobedience, and is now returning simply because of the fantastically generous, indeed prodigal, love of her god. But this is a highly subversive retelling. The real return from exile, including the real resurrection from the dead, is taking place, in an extremely paradoxical fashion, in Jesus’ own ministry.”
The older brother represents Jesus’ self-righteous critics, “virtually Samaritans.” They are “defining themselves as outside the true family,” Wright explains. Jesus has flipped the national narrative like a giant pancake on the griddle, as the prophets so often had done before him. Only with this further spin: the spotlight falls now not on some vague but glorious future, an ideal and as yet unrealized “Suffering Servant” or “Son of David,” but on the man standing in front of Jesus’ critics: the preacher accused of hanging with outcastes and lowlifes. And the whole world (a mission calling mentioned throughout the Old Testament, but never seriously followed) would finally be brought into Israel’s story:
“It is time for the Gentiles to come in, because Israel’s exile is at last over, and she has been restored.”
For Jews, restoration should mean God’s return to the temple. Jesus cleansed that temple, a symbolic act Aslan confuses with mere sedition. Jesus was not just causing a ruckus: he was reminding Israel that divine visitation was a call to repent. Wright points out that Luke could not have invented the ever-so-Jewish, but subversive, theme of a rebuilt Temple that is laced throughout early Christian literature. Yet the theme of Israel’s Messianic restoration, then mission to the world, was “held in common with all the other major early Christian writers” (128).
Thus, “like a great pincer movement,” we “work inwards towards Jesus” from Jewish context and early Christian theology. The “simplest solution” to explaining this mass of complex but converging data (having added a dialectical alloy, Wright’s method thus strengthens the concept of coherence) - the meteor’s impact, the birth of a new family - is “that Jesus himself believed that he was the agent of his strange return from exile.” The resurrection would be God’s stamp of approval upon his ministry. All this - resurrection, forgiveness, restoration, return, the rule of God - was occurring “under the noses” of the “self-appointed stay-at-home guardians of the father’s house” (128).
God thus proved kind as the prophets predicted, but prodigally kind, kind in a revolutionary, even threatening way. Israel “could say to her god ‘I wish you were dead,’ but this god would not respond in kind. When, therefore, Israel comes to her senses, and returns with all her heart, there is an astonishing, prodigal, lavish welcome waiting for her” (129).
The Prodigal Son thus does not merely teach, in an abstract sense, it embodies or incarnates truth, it “creates a new world.”
This is why Jesus’ story, drawing in the whole ministry that the tale encapsulates, felt to some listeners like a sucker-punch to the gut:
“It is not a matter . . . Of Jesus offending some petty scruples here or there, or of an abstract challenge offered by one timeless religious system to another. Jesus is claiming to be ushering in Israel’s long-awaited new world; and he is doing it, apparently, in all the wrong ways. Jesus is enacting the great healing, the great restoration, of Israel. And he interprets his own actions in terms of the fulfillment, not of a few prophetic proof-texts taken atomistically, but of the entire story-line which Israel had told herself, in a variety of forms, over and over again” (130).
Wright begins with the Prodigal Son, but argues that this algorithm draws in the whole gospel story of redemption. “Dramatically, historically, theologically, the parable fits perfectly into the ministry of Jesus . . . Jesus is reconstituting Israel around himself” (131).
The world loves the story of the Prodigal Son. It is the sort of tale a 19th Century novelist would make hay of. (And come to think of it, Charles Dickens also loved this story and borrowed its plot, for instance in Great Expectations. Forrest Gump’s prodigal love towards Jenny can be read the same way.) To say this story “coheres” with the rest of Jesus’ ministry is an almost comical understatement. The Prodigal Son draws Jesus’ ministry around it like a well-tailored suit. It is a perfectly-chosen final chisel stroke that gives the Thinker’s eyes their intensity, the fingers almost touching as God reaches out to Adam on the ceiling of the Sistine Chapel.
What does this master stroke of a rhetorical gambit have to do with historical evidence? Simple. The gospels are “Facebook postings” from a particular period in Christian history, testable and datable debris scattered from the impact crater of historical causation. Wright explains:
“The parable only makes sense as a retelling of Israel’s story; but it also only makes sense as a profoundly subversive retelling of that story . . . As a parable, not least in its manner of concluding one scene too early, it makes sense precisely at that moment in history when the possibility of Israel’s redemption happening in this fashion is being controversially mooted, not when it is being climactically and publicly celebrated. The parable thus fits exactly into the gap between Judaism and early Christianity . . . It is thus decisively similar to both the Jewish context and the early Christian world, and at the same time importantly dissimilar . . .” (131-2, Wright’s emphasis)
From this discussion emerges Wright’s criterion of double similarity:
“When something can be seen to be credible (though perhaps deeply subversive) within first-century Judaism, and credible as the implied starting point (though not the exact replica) of something in later Christianity, there is a strong possibility of our being in touch with the genuine history of Jesus.”
Already Wright is hinting at a second and complementary half to the criteria. Even stronger evidence of historicity is found when not only does a given story or scene fit like hand in glove within a duel historical context - say, between falling in love and having a child - but when part of the story differs doubly from “before” and “after” contexts as well. (And thus is “deeply subversive” of what came before, and not an “exact replica” of what comes after, either.) Your honeymoon was a distinctive era of your life: you were no longer merely your parents’ child or a lonely single, but neither had the baby arrived. But that life made no sense apart from your own parents, and the subsequent growth of your family and its smallest members is best explained as the fruition of that union.
Later Wright argues that “double similarity and double dissimilarity must characterize any analysis that claims historicity” (226). This seems a bit much. As Wright says about the Prodigal Son, “one swallow does not make a summer,” and we shall host a large flock of evidences for the gospels in subsequent chapters. But Wright is right to recognize DSDD as a sweeping pattern to which much of the gospel material does indeed conform, and which supports the historical truth of that material. Consider even the famous phrase “The Kingdom of God,” which Aslan supposes is code for La Revolucion. Jesus announces in Matthew and Mark, “The time is fulfilled; the kingdom of God is at hand. Repent, and believe in the good news!” Wright points out that even here, Jesus’ words are almost unprecedented:
“No one in Judaism had said quite that before, but the sayings make no sense except in a firmly Jewish context. Equally, the early church, venturing beyond the borders of Judaism, did not announce the kingdom in these terms - they would have meant nothing to Gentiles - and yet the announcement they made, and the life they led, are unthinkable without this kingdom being believed to have come in a still very Jewish sense. They were not, after all, offering ‘a different religious option’ to a world already sated with such things. They were announcing that the one true god, the creator, had fulfilled his purpose for Israel and was now, in consequence, addressing the whole world” (227).
Jesus did not “address” the world as a military conqueror, as Aslan supposes. Wright sardonically notes a similar proposal that predated Aslan by some 23 years, “The authors are to be congratulated on finding yet another new way of making Paul the corrupter of the religion of Jesus” (450n). Rather, in the face of cruel Roman imperialism, Jesus called Israel to repent of her “militaristic nationalism.” Israel’s true calling was not to merely kill Roman soldiers and set up a new mega state, but to bring light of a new sort to the world:
“One of the key elements in Jesus’ perception of his task was therefore his redefinition of who the real enemy was; then, where this enemy was actually located; then, what this enemy’s strategy was, and how he was to be defeated . . . (this theme) looms large in the gospels. It is comparatively scarce in other early Christian literature, and is very differently treated in non-Christian Jewish literature of the time. At the same time, it is a thoroughly Jewish perception of reality, and makes excellent sense as the presupposition of what we find in early Christianity. It thus meets the test, which is of course only ever applicable in a broad-brush way, of double dissimilarity and double similarity” (450).
Again and again, even the most “ace” among our ACE detectives adopts schemes of interpretation that simply ignore large swaths of historical data. Aslan and Carrier go so far as to pretend that Jesus didn’t even tell his followers to love their enemies. Wright’s dialectic, by contrast, has the merit of preserving contrasting shards of evidence within a coherent whole. Yes, Jesus was “a Messiah,” as Aslan argues. But “Messiah” took on new meanings in light of his personality and mission. (As the word “Sage” [聖人] would gain new meaning in the wake of Confucius’ life - another great thinker whose historicity is I think supported by DSDD.)
Wright noted that scholars are coming to recognize that the Messianic awareness permeating the gospels can hardly have been pure Christian novelty. Why would Jesus’ first followers make up a “Messiah” so far at odds with the expectations of the Jewish people? “Why bother to invent passages, sayings, and above all a title that would be at best beside the point and at worst dangerously misleading?” (488-9) Jesus was a Messiah whom Jews did not expect, but who could not have appeared anywhere else. He was the savior Christians would worship, but more complex, edgy, even quirky, and unpredictable than the simplified figure of later Christology - yet only such a person could produce such a creed:
“We may suggest that the portrait of Jesus as Messiah in the synoptic gospels is not only significantly different from what the Jewish context would have led us to expect (though is makes sense only within, and as a key variant upon, that Jewish setting). It is also significantly different, both in context and in the tone of presentation, from what we find in the early church (though the church’s proclamation of Jesus as Messiah makes sense only if we presuppose something like the gospels’ picture) . . . As in other cases, the picture the gospels paint is both continuous and discontinuous with non-Christian Judaism on the one hand and the life of the early church on the other, in such a way as to force the historian to postulate that we are here in touch with Jesus himself” (489).
How much of the gospels does Wright’s method for seeking historicity vindicate? Most of the framework and quite a bit of the finish, I think. The gospels are deeply Jewish. Even Luke cannot be understood in any other cultural context. Yet they break with Judaism - no break is not the right word - Jesus does not abolish, but he fulfills on unexpected terms and with surprising force. No one predicted the sort of fulfillment whose characteristics I shall describe.
It may sound like a joke to ask, “Are the gospels Christian?” They are the founding texts of Christianity, its Magna Carta, Bill of Rights, and Constitution rolled into one. The past two thousand years are the impact crater of this missile: Augustine, Francis, Thomas Aquinas, cathedrals, universities, missions, stained glass windows, Handel’s Messiah, the names of Hispanic baseball players (and my two sons) - all derive from these four small texts.
Yet Christianity never produced anything like them again. Read the hagiographies that Ehrman reproduces of Paul, Peter, John, or Thomas. The atmosphere has changed. We have crossed a great frontier. The child in the crib has graduated from college and gone out into the world.
The power of Double Discontinuity, Double Continuity lies in its scope. It does not cover a few random verses, or one or two analogies. The gospels are deeply Jewish, yet stand out dramatically from Hebrew tradition. They are the origin of Christian tradition, yet could not have been, and were not, written again, after those first few years of life.
The rest of this book may, if you like, be read through this grid.