When the Spanish conquistadors returned to Europe, among the treasures they brought with them were three Maya codices or books. Today, these documents — focused in each case on calendrical and astronomical matters — are named for the cities whose museums hold them: Dresden, Paris and Madrid.

But was a fourth Maya codex found in the 1960s?

Around 1965, or so the story goes, two looters discovered several illustrated bark-paper sheets in a cave in the Mexican state of Chiapas. In 1971, having come into the hands of a Mexican collector via a story right out of a Hollywood film, the documents were displayed in New York City’s Grolier Club, and they’ve been known since then as the “Grolier Codex.” But then they vanished. Since reappearing in 1977, they’ve languished undisplayed in the basement of Mexico City’s National Museum of Anthropology.

Like the three codices held in Europe, the Grolier Codex is astronomical. It’s focused on the movements of Venus, the basis of the Maya calendar. However, it’s shorter, less detailed, rather poorly crafted and in relatively bad shape. About a third of each page is missing, and nine pages (of its original 20) have been lost altogether.

The Grolier Codex was controversial from the start. In particular, the famous Mayanist Sir J.E.S. Thompson took aim at it, labeling it a fraud.

Now, though, a press release on Sept. 7, 2016, from Brown University reports on a study conducted by four of the world’s most eminent living Mayanists (including Brown’s Stephen Houston, who, though non-Mormon, taught at Brigham Young University 1994-2004). They reviewed “all known research on the manuscript,” examining it “without regard to the politics, academic and otherwise, that have enveloped the Grolier.” (“It became a kind of dogma that this was a fake,” says Houston.)

The new study analyzes accounts of the discovery of the Grolier manuscript, its style and iconography, the character and meaning of its astronomical tables, carbon dating and other scientific data about the manuscript, and the craftsmanship of the codex, ranging from Mesoamerican papermaking methods to Maya artistic techniques.

A 20th-century forger would need to have known (or successfully guessed) several things in order to create the Grolier, and the scholars argue that it simply couldn’t have been done: For example, the forger would need to have guessed the existence of deities that hadn’t been discovered by the mid-1960s and then to render them perfectly; figured out how to create Maya blue pigment, which wasn’t created in a laboratory until the 1980s; and have deployed “a wealth and range of resources” depending, in some cases, on knowledge that was unavailable until recently.

The authors of the study believe that they’ve now answered essentially every objection to the authenticity of the Grolier Codex.

“A reasoned weighing of evidence,” they conclude, “leaves only one possible conclusion: four intact Maya codices survive from the Pre-Columbian period, and one of them is the Grolier.” Says Houston, “There can’t be the slightest doubt that the Grolier is genuine.”

In a brief 1997 article titled “The Sobering Lesson of the Grolier Codex” (available at archive.bookofmormoncentral.org/node/301), John Sorenson and John Welch offered five observations linking the Grolier controversy to the Book of Mormon:

1. Those who regarded the Grolier Codex as a hoax were prejudiced by the unconventional manner of its finding. Yale’s Michael Coe, a longtime defender of the Grolier and a co-author of the new study, believes that, had the Grolier’s origin been less controversial, it would have been “accepted by even the most rock-ribbed scholar as the genuine article.”

2. Its antagonists scarcely gave the Grolier serious examination — which is very reminiscent of the Catholic sociologist Thomas O’Dea’s 1957 quip that “the Book of Mormon has not been universally considered by its critics as one of those books that must be read in order to have an opinion of it.”

3. Those who dismissed the Grolier Codex were often closed-minded, responding not reasonably but reflexively.

4. When they bothered to examine the Grolier, critics often focused on nitpicking details, seeking a “quick kill.” It was, they felt, too obviously bogus to deserve serious examination.

5. Opponents of the Grolier’s authenticity frequently resorted to name-calling and dismissive epithets rather than rational argument.

None of this proves the Book of Mormon true, of course. But observant members of The Church of Jesus Christ of Latter-day Saints will easily recognize remarkable parallels between the treatment of the Grolier Codex and the way the Book of Mormon is often summarily dismissed without a genuine hearing.

Daniel Peterson teaches Arabic studies, founded BYU’s Middle Eastern Texts Initiative, directs MormonScholarsTestify.org, chairs mormoninterpreter.com, blogs daily at patheos.com/blogs/danpeterson, and speaks only for himself.