The Shroud of Turin and the nature of faith

What ought to be the relationship between evidence and belief?

Miniature representing the Shroud of Turin, from the Prayer Book donated in 1559 by Cristoforo Duc of Moncalieri to Margaret of Valois, Turin, Royal Library. Image by Andrea Nicolotti.

Almost a year ago I was invited by Andrea Nicolotti, a professor of History of Christianity and Churches at the University of Turin, in northern Italy, to teach a special course on the relationship between science and religion or, more broadly, reason and faith. It was a lot of fun, and Andrea and I have become fast friends, so much so that I’m very much looking forward to returning to Turin this summer for another course, on the philosophy of pseudoscience.

The two things, religion and pseudoscience, are not unrelated, and it turns out that Andrea is a world expert on the famous Shroud of Turin, the alleged burial cloth of Jesus. I highly recommend his definitive treatment of the topic, The Shroud of Turin: The History and Legends of the World’s Most Famous Relic. (Here is a recent article by Andrea, summarizing the history and controversy surrounding the Shroud.)

The story of the Shroud is interesting and pertinent to discussions of both pseudoscience and the relationship between reason and faith because it is arguably the most famous relic of the Christian faith, which many people, including many religious authorities, consider authentic and indeed one more proof—together with other miracles and testimonies—of the veracity of the Gospels.

But not every religious authority agrees on the relevance of the Shroud and of similar artifacts. Michael Shermer, publisher of Skeptic magazine, recently hosted an op-ed by David E. Pierce, a Catholic Deacon (i.e., an ordained minister of an order ranking below that of priest), challenging the significance of the sort of debunking carried out by Andrea and others and putting forth a different model for the relationship between science and religion. I think Pierce’s article is representative of a whole approach to the issue, so it is worth taking a look at what he says as well as at Andrea’s commentary, using the discussion to get a bit more clear on the issue at hand.

In his essay, Pierce makes two somewhat disjointed points: (i) That the Shroud was actually a fake concocted by none other than Leonardo da Vinci, on behalf of the Savoy family, the same dynasty that later became the first (and last) kings of Italy; (ii) That believers should not focus on material proofs to support their faith because that contradicts its value. I’ll start with a brief commentary on the first point and devote much of the space below to the second one.

Pierce is “intrigued and swayed” by the hypothesis that Leonardo faked the Shroud at the Savoys’ request in 1492, using a camera obscura and a technique that involved prolonged exposure to the Sun as well as the use of chemicals like silver sulphate. The camera obscura would have allowed Leonardo to use a live model standing outside the box, whose sun-lighted image would have been projected on the Shroud and fixed by the chemicals. Pierce himself refers to this hypothesis as “admittedly untestable,” which does not bode well for his endorsing of the story.

Why would the Savoy commission the fake? To enhance the prestige of their House, naturally, and even, possibly, to make money out of the relic. This is certainly true, as we know—thanks in part to Andrea’s work—that they did acquire a fake Shroud (whether they realized it or not), back in 1453. According to Pierce, they just didn’t like the way the old Shroud looked, so they asked Leonardo to make a new, “more believable” one. I’m no expert on the specific subject, so I asked Andrea what he thought of the idea:

“The notion that Leonardo faked the Shroud is entirely unconvincing. To begin with, he lived a century after the Shroud pops up in the historical record. There is no cogent reason why the Savoy would have commissioned a new one to substitute the original. And nobody has ever seen the proto-image allegedly generated by Leonardo. Moreover, the human figure on the Shroud does not have the characteristics of a photograph. Finally, for the proposed mechanism to work Leonardo would have had to use chemicals of which there is no trace on the actual Shroud.” (Personal communication)

Good enough for me. Regardless of whether Pierce or Andrea are right, both regard the Shroud as a fake, so the real question is what to make of the fact that so many believe it to be genuine, and what that tells us about the relationship between reason and faith.

Pierce begins his criticism of evidence-based religious belief by attacking a famous colleague: “Very influential and renowned Bishop Robert Barron, who I admire, of the evangelizing Word On Fire Institute and ministry, passionately and reverently declared in his 2024 Easter on-line homily that the Shroud was ‘the most famous relic in Christendom—the cloth that covered the body of Christ in the tomb—the same cloth we can see and bring us to belief: the moment of the Resurrection through the power of the Holy Spirit.’ In 2023, Bishop Barron had over 3.1 million Facebook fans; 1.86 million YouTube subscribers; 530,000+ Instagram followers; and 324,000+ X followers.”

Let’s set aside the sad observation that these days the accepted measure of relevance is one’s number of followers on Facebook, YouTube, Instagram, and X. (For the record, mine are, respectively: 0, 0, 0, and 0. Ah, the pleasure of quitting social media!)

Pierce continues by saying that “religious faith should not demand or expect proof,” because “Needing proof undercuts Catholic faith in things not seen.” Moreover:

“Much of Christian faith requires a suspension of disbelief, meaning sometimes we must suspend our critical thinking and logic in order to enjoy a story, and there are many rewarding, compelling, and enlightening faith stories to enjoy that appeal to and enlarge the heart, mind, and soul.”

I personally find the open advocacy of suspension of critical thinking to be deeply disturbing, and the source of much that is wrong with human society. That’s the same attitude that, in a different context (political rather than religious ideology) has brought us the infamous “fake news” and “alternative facts.”