A new collection of Vincent van Gogh’s letters casts doubt on the popular notion that his mental illness was also the source of his artistic genius.

A curator at the Van Gogh Museum in Amsterdam, Leo Jansen, and two Dutch colleagues are working on a complete annotated edition of the artist’s more than 800 extant letters. The new edition will also include around 2,000 illustrations, artwork by van Gogh himself and by other artists that he refers to in his letters.

Although the full volume won’t be published until 2009, a preview of sorts, including 22 letters from van Gogh to his friend, the poet and painter Émile Bernard, has just been published by Rizzoli, in collaboration with the Morgan Library & Museum and the Van Gogh Museum. The book, “Vincent van Gogh, Painted With Words,” accompanies an exhibit at the Morgan, opening next month, where 20 of the letters will be on display, along with around two dozen paintings, drawings, and watercolors that the artists either discussed or exchanged.

The letters to Bernard, which van Gogh wrote between 1887 and 1889, mostly from Arles, show him working out problems of technique; monitoring his health and reveling in the wholesomeness of rural life, and then, after his blowup with Paul Gauguin, in which he cut off a piece of his ear, worrying about whether his mental and physical state would allow him to continue painting.

This correspondence shows that the ear episode and subsequent hospitalization had shaken the artist’s confidence. “It was the first deep crisis he got into,” Mr. Jansen said. “It became clear that he was really a mental patient, and he knew that this would affect his abilities as an artist,” he continued. “Making art the way he did cost a lot of both physical and intellectual effort, and he felt he wouldn’t be able to work as well as he did before.”

Mr. Jansen said that he was asked once to attend a conference on bipolar disorder, to discuss whether van Gogh was bipolar and his creativity a product of mania. The curator disagreed, irritating the medical experts. “I tried to look at all the facts in a more neutral way, and not follow the myth,” he said, but “I was talking to deaf people.”

Although van Gogh wrote many more letters to his brother, Theo, who supported him and whom he therefore felt obliged to update on his activities, his letters to Bernard were more spontaneous and more detailed, Mr. Jansen said. “These letters are a kind of overview of everything he thought, about life, about art, about religion,” he said. Among the subjects van Gogh discusses are his wish that modern artists would band together and collaborate, rather than competing, and his belief that painting and frequent sexual intercourse are mutually exclusive, because sex enfeebles the brain.

Bernard is one of those figures who has faded from history but was intimately connected to the artists and writers of his time. Van Gogh met Bernard, who was 15 years his junior, in Paris in 1886, and the younger man introduced him to members of the avant-garde like Henri de Toulouse-Lautrec. In early 1888, van Gogh left for the south of France, hoping to live more cheaply, regain his health, and find new subject matter and a brighter color palette. He refers in one letter to the wine and steaks of Paris having stopped his blood flowing.

The move fulfilled its purpose. In June, from the south, he wrote to Bernard of his excellent health: “I even work in the fields here at midday, inthefullheatofthesun, without any shade whatever, and there you are, I revel in it like a cicada.”

The imagery in the letters “gives us a sense of a body that was inhabited by van Gogh, not just a mind,” the curator of the exhibition at the Morgan Library, Jennifer Tonkovich, said. “It’s not just what he thought about color theory.”

But van Gogh did write a lot about paintings he was working on, and the letters include several sketches of works planned or in progress, with areas marked as blue, green, yellow, pink.

In October 1888, Gauguin went to stay with van Gogh in Arles. In December, they had the famous fight that led to van Gogh’s cutting off a piece of his ear and Gauguin’s departing for Paris. Van Gogh’s letters do not give us any clue to what happened, Mr. Jansen said. “The only thing he writes to Gauguin is: ‘Was it really necessary to leave me?’ But the word ‘ear’ does not appear in the correspondence at all.”

What we know about the incident, Mr. Jansen continued, comes from a brief police report, which mentions that van Gogh wounded himself, and from Gauguin’s memoirs, which may not be entirely reliable. “He says that van Gogh chased him through the park, making all kinds of noises,” Mr. Jansen said.

In 1889, van Gogh, who also suffered from epilepsy, checked himself into an asylum in Saint-Rémyde-Provence. He wrote Bernard two letters from there. Then, on July 27, 1890, he shot himself in the chest.

“We do not exactly know why he committed suicide,” Mr. Jansen said. “There is no letter to his brother or anybody else saying: ‘I quit because of this or that reason.'”

In his last letter to Bernard, van Gogh alluded to his physical and mental battles: “[I]f I haven’t written for a long time, it’s because, having to struggle against my illness and to calm my head, I hardly felt like having discussions, and found danger in these abstractions.”

After van Gogh died, Bernard became a major champion of his work. He helped organize a retrospective of his paintings in Theo’s apartment, and then another in the Galerie Le Barc de Boutteville. He also saw the potential in van Gogh’s letters. In 1893, he published excerpts of van Gogh’s letters to him in the periodical Mercure de France. In 1911, he collaborated with the dealer Ambroise Vollard to publish a complete edition of these letters.

The exact provenance of the letters is not clear. Bernard appears to have sold them at some point in the 1920s, because in 1929, Count Harry Kessler noted in his diary having seen a group of letters displayed at a dinner party at the Berlin home of Marianne Goldschmidt-Rothschild. After a sumptuous meal, he wrote, “thirty letters by van Gogh, in an excessively ornate, horrible binding, were handed round with the cigarettes and coffee.”

One of the 22 letters van Gogh is known to have written to Bernard has been lost, and another is in a private collection and was unavailable for the Morgan show. Of the 20 on exhibit, 19 have been promised to the Morgan by their current owners, Eugene and Clare Thaw.

The complete edition of van Gogh’s letters being organized by the Van Gogh Museum is not the first such compilation. It will replace an edition published in the 1950s. Mr. Jansen said that the earlier edition was missing some letters, had others in the wrong order, and included transcription errors. In van Gogh’s last letter to Bernard, for instance, he describes a painting he has done of the garden at the asylum in Saint-Rémy. The painting’s dark colors, he writes, evoke the feeling of anxiety that his companions feel. He describesthisfeelingwiththeFrench expression voir rouge, or “to see red” — only in the earlier edition, it was wrongly transcribed as noir rouge, or “black red.” “Somehow nobody every doubted it or asked what kind of expression this was,” Mr. Jansen said.

The letters will be published in Dutch, French, and English editions, as well as on the Internet in all three languages. The Internet version will likely be searchable by key words, dates, and names, Mr. Jansen said. Interestingly, this will not be the first Web site to offer access to van Gogh’s letters. A site maintained by WebExhibits, and funded with a grant from the U.S. Department of Education, has all of the artist’s letters that were included in the old English edition. They are searchable by such terms as “materials,” “technique,” and “theory,” as well as “paranoia,” “masochism,” and “suicide.”

The executive director of the Institute for Dynamic Educational Advancement, which runs WebExhibits, Michael Douma, said, “There is no competition, or frankly communication between us and the Van Gogh Museum.”

Mr. Jansen, his co-editors, and Ms. Tonkovich will speak at a symposium at the Morgan on September 29.