Some guys who are publishing a book claim some of the paintings in a recent Van Gogh exhibition at the Phillips Collection aren’t in fact by Van Gogh. The Phillips Collection, citing the most respected authorities in the field, says that’s preposterous. Ordinarily this would be the end of the matter, except we live in an age of skepticism, which flourishes on the skeptical medium par excellence, the internet, where authority is all but helpless against speculation.

Van Gogh’s works have been plagued by accusations of forgery for more than a century, at least as far back as an important 1901 retrospective in Paris. In the 1920s, one of the most notorious art forgery scandals, perpetrated by the German art dealer Otto Wacker, also embroiled Van Gogh. And as the catalog to the Phillips exhibition “Van Gogh: Repetitions” (which closes on Sunday) states: “The problem has hardly disappeared. Experts now speculate that there may be more than forty-five forgeries” listed as authentic in important catalogs that document the artist’s oeuvre.

But, as the Benoit Landais and Hanspeter Born claim in “Schuffenecker’s Sunflowers: And Other van Gogh Forgeries,” eight of the works in the Phillips Collection exhibition (which opens in Cleveland on March 2) are the work of Emile Schuffenecker, a contemporary of Van Gogh. Schuffenecker was a painter himself, and a collector of Van Gogh’s work, and it seems he may have retouched or added to some Van Gogh paintings. But no one has proved he fabricated any paintings wholesale, and the works in Phillips Collection are almost universally accepted as authentic.

“I don’t have any question about their authenticity,” says Eliza Rathbone, the Phillips Chief Curator. And how does she know that?

“The one thing that we can point to is the expertise of the Van Gogh Museum in Amsterdam, which possesses the greatest, largest collection of works by Van Gogh whose authenticity can’t be challenged, because they came directly from Theo’s widow.” Theo was Van Gogh’s brother, supporter and an art dealer. Rathbone also cites close scrutiny of letters and documents related to the works in question, and study of the materials including canvass and pigments. Regular contact with works that are certainly authentic gives scholars from the Van Gogh Museum the expertise to adjudicate authenticity in other works.

But Hanspeter Born is an enthusiastic practitioner of skepticism, and has been sending out regular email blasts: “It seems to me that you might have a story, even a scoop,” he wrote recently. Not exactly. His co-author Landais was active in the forgery sleuthing business back in 2007, when ARTnews reported: “The most extreme charges came from Benoít Landais, an outsider and enfant terrible who delighted in challenging orthodoxy. His success at grabbing headlines had spawned a cottage industry of enthusiastic amateurs who argued with each other and the scholars.”

Scholars, including Rathbone, admit there are forgeries out there. And the “Repetitions” exhibition touches on some of the issues that make an artist particularly susceptible to concerns about authenticity. Van Gogh painted multiple versions, and sometimes copies, of the same image throughout his career, and that restlessness can make it difficult to define the exact parameters of his accepted “style.”

“Vincent’s habit of making copies proved to be a godsend to forgers,” the authors claim in a summary of their book sent to journalists.

Rathbone isn’t swayed from her conviction about the works exhibited by the Phillips. During the exhibition the museum invited professionals from around the world to spend time with the paintings on a day the museum was closed to the public. No one, she says, had any doubts about any of the works on display. Officials at the Cleveland Museum of Art have also dismissed the claims.

But we live in an information culture that has no memory, which means claims and counterclaims are perpetually new, and past refutation counts for nothing.