Ever since the 1988 radiocarbon tests of the Shroud of Turin, the laboratories’ conclusion that the fabric dates from between 1260 and 1390 “with 95% [statistical] certainty” has undergone considerable scientific scrutiny and challenge. In March 2019, a paper published in the scientific journal Archaeometry by a team of French scientists undermined the labs’ analyses. Though this report may not be the final nail in the coffin of the dating debacle, it ought to be clear by now that uncritical acceptance of the tests’ results is unwarranted. The “medieval forgery” theory, which was never scientifically or historically plausible, remains unproven.
A Thumbnail Sketch of the 1988 Debacle
If we follow the story of the 1988 dating project as told in Fr. Vittorio Guerrera’s The Shroud of Turin: A Case for Authenticity, ironically, the Vatican bears much of the responsibility for incompetently subverting the test. Among other errors, the scientist who cut the samples, working under the direction of two textile experts unfamiliar with the Shroud, took all of them from near a repair patch made in the 16th century rather than from different areas of the cloth. As the French scientists recently reported, the raw data from the tests “strongly suggests” that “homogeneity is lacking;” i.e., the samples were contaminated.
Quite apart from the cutting of the samples, there were other errors of test integrity. For one, the control samples sent with the Shroud samples didn’t match its weave, defeating the “double-blind” nature of the test. One scientist admitted you could tell which one was the Shroud sample using pictures from a National Geographic article. For another, a third set of unnecessary control samples for which the labs were unprepared was delivered separately, in envelopes rather than the stainless-steel tubes in which the others had been sent.
The scientists performing the test complained and protested the departures from the 1986 “Turin protocol” devised to guide the process. Even assuming their ignorance of the cutting fiasco, they had every reason to believe the integrity of the experiment had been compromised, undermining its credibility. Whatever doubts they had, however, didn’t show in either the press conference releasing their conclusions or in the Nature article in which their findings were published. Arguably, by that time, they’d vested too much money, time, and personal credibility in the success of the tests to admit failure.
Some Limits of Science
As far as scientific credibility goes, however, the press and the skeptic community have taken the 1988 tests at face value precisely because they were performed by scientists using a scientific procedure. Journalists generally don’t have the background to question scientific results. Even those of us who are more scientifically educated usually bow before the certified experts, as well we should. My first intimation that the Shroud results were under fire came in 1993—oddly enough, from my organic chemistry professor, who testified movingly to the integrity of a friend who had participated in the tests.
But science is first and foremost a method, not a machine, far less a perfect machine. Scientists themselves are humans, capable of mistakes, prone to cognitive biases, and subject to all the temptations the rest of us mere mortals face. It isn’t necessary that scientists or their methods be perfect for us to generally trust their results. But it is necessary that scientists perform their work with integrity, which includes acknowledging their biases and admitting their mistakes. This also includes accepting the limits of their tools; even a golden hammer can only do a hammer’s job.
Radiocarbon dating has its limits. While its utility and accuracy have been improved in the last 30 years, the processes used on the Shroud were known to occasionally produce results at variance with other known facts even before 1986. Experiments done after 1988 questioned whether the washing and calculating methods would have neutralized such contaminating factors as “youthening” due to smoke from a 1532 fire or the presence of a biopolymer that previous researchers had mistaken for Spandex particles. In simple terms, archaeometrists knew at the time that carbon-14 dating’s reliability had been oversold to the public.
The Anonymous Super-Genius
The “medieval forgery” theory asks us to believe a medieval super-genius was able not only to transfer a latent 3D image of a beaten and tortured man onto linen but also other interesting details that show up only in a modern laboratory environment using modern tools. His technique was so specific that, despite his being limited to High Middle Ages technology, every attempt to reproduce the method has failed or omitted at least one key characteristic. Furthermore, this monstrously clever person left no other clue to his existence except an allusion in the draft of a bishop’s letter.
That’s a lot to swallow. Perhaps an extraterrestrial mischief-maker was pranking us.
The “medieval forgery” theory requires a plausible explanation of its creation that fits all the key characteristics of the Shroud image. In particular, such an explanation would have to show how the forger dehydrated and conjugated the cellulose structure of only the topmost fibrils of each thread in the image areas of the Shroud, using only tools available in the thirteenth or fourteenth century. It would also have to avoid paints, dyes, and any medium that would bind the fibers. To date, none of the attempts to reverse-engineer the presumed forger’s technique have succeeded—the parameters are too specific.
“Well, I don’t need to know how it was forged to know that it was forged,” one might grouse. The failure to prove the Shroud a fake doesn’t by itself prove the Shroud an authentic first-class relic, of course. But when the evidence for fraud consists solely of a compromised radiocarbon test and a 14th-century bishop’s accusation (which tells us neither the forger’s name nor how it was done), simple mulish insistence is hardly persuasive. The preponderance of the evidence to date is against the “medieval forgery” theory.
What the Shroud Suggests
I’m not arguing that the Shroud is authentic, though I would be pleased if it is. The Shroud isn’t part of the general revelation; therefore, belief in its authenticity isn’t binding on Catholics (cf. Catechism of the Catholic Church 67). Rather, I’m saying that the “medieval forgery” theory is inherently untenable. The 1988 radiocarbon dating was a skeptical “Hail Mary” pass that the receiver fumbled at the goal line (partially due to defensive interference). But even had the “Turin protocol” been followed to the letter, it isn’t clear the tests would necessarily have led to an accurate result.
The thing is, even if the Shroud was Christ’s, it doesn’t prove anything—it merely suggests. To be sure, it’s extraordinary evidence of a unique event; but what the event was, from a physics standpoint, is unknown and perhaps unknowable. The coincidence that this unique event happened to the body of a historical figure about whom we Christians make astonishing claims is unusual but not especially revealing. It may depict the moment Jesus’ body was not only revived but transformed into something altogether new and supernatural, something more real than we can imagine. Then again, it may not.
But what the Shroud suggests, I suspect, is more disturbing to some people than anything it can prove.
Forget about atheists and agnostics—many self-identified Christians are uncomfortable with miracles. To the worldly, sophisticated disciple, they smack of ignorance, deception, and credulity. Many are much more comfortable thinking of the Resurrection as a metaphor and the Eucharist as a symbol; they would much rather that God stay on His side of the cosmos, an interested but uninvolved onlooker. Things like miracles of healing, stigmata, and incorruptible bodies may be inexplicable now; but eventually, they believe, Science will neutralize them as natural phenomena.
But Nature has no discernable reason for blindly producing things like the Eucharistic miracle of Lanciano or the Shroud of Turin. They seem to exist for no other reason than to point to the truth of certain Catholic and Orthodox beliefs—that Jesus really did rise from the dead, that he really is present in the Eucharist, and that (most wonderful of all) God isn’t content to be a spectator as we blunder on toward our destinies. A God that can interfere at will with the natural order of things is a God that can rightfully make demands of us.
It isn’t sufficient for such people, then, to neutralize them as natural phenomena. They must be debunked as frauds. Their continued existence pokes us right in our sophistication; they throw off our materialist groove. To paraphrase George Bernard Shaw, Christ must be crucified in every generation for the benefit of those who have no imagination.
British journalist Peter De Vries once wrote on another subject, “For those who believe, no proof is necessary. For those who do not believe, no proof is possible.” It’s as if the Shroud of Turin exists precisely to support this observation: Even though the “medieval forgery” theory is the least credible of all explanations, those who need to believe it will continue to accept the 1988 radiocarbon dating no matter how many future analyses discredit it. But this acceptance isn’t because of all the facts but rather in ignorance of, or even despite, all the facts.
Ironically, it was science that discovered all the many hard-to-duplicate details of the Shroud, science that has rendered “medieval forgery” so much wishful thinking. Science may never confirm the identity of the Man in the Shroud, but neither will it ever succeed in debunking the Shroud. The more you learn about it, the more you realize that debunking it is a fool’s errand and that accepting it as authentic is a more rational response to the empirical data. All the 1988 radiocarbon dating has proven is that scientists are prone to confirmation bias too.