One hundred and twenty-eight years after Vincent van Gogh took a razor to his ear — signaling the start of the tumultuous months leading up to his suicide attempt and death — we remain fascinated by the nature of the artist’s illness. There’s no definitive diagnosis for what caused his many unpredictable bouts of strange behavior; doctors had a tough time figuring out what ailed the artist, suspecting everything from depression to epilepsy, fueled in part by the Dutchman’s affinity for coffee and the green fairy. Dr. Marie Jules Joseph Urpar, who in 1888 examined van Gogh at a hospital in Arles, after he had cut off his ear, said the artist had “suffered an attack of acute mania with generalized delirium.” The painter’s symptoms and various diagnoses are under examination for the first time in an exhibition at the Van Gogh Museum in Amsterdam. It brings together paintings, drawings, and letters that recount one of the most famous but mysterious periods of art history.

The discovery of one letter that’s making its public debut in the show exemplifies just how captivated we are by van Gogh’s story. Written by Dr. Rey Félix, who treated and dressed the artist’s head wound, the paper includes drawings of the mutilated ear that confirm van Gogh sliced off almost the entire organ, rather than just a portion of it — an issue that has long spurred debate. Félix made his illustration in August 1930, a full four decades after van Gogh died, and sent it the late biographer Irving Stone; researcher Bernadette Murphy then found it in 2010 in an American archive while researching her own book focused entirely on van Gogh’s ear.

It’s easy to label a man who cuts off his own appendage crazy, but, in spite of its title, On the Verge of Insanity: Van Gogh and his Illness takes care to separate the artist’s creative output from whatever darkness plagued him. He was not — as 19th-century Symbolists influenced by neurological literature may have believed — a creative madman with visionary capacities.

“Van Gogh never painted while suffering an attack of his illness, with the exception of a single period in the asylum in the early spring of 1890,” the museum’s van Gogh research curator, Louis van Tilborgh, writes in an accompanying catalogue. “His artistic achievement was most definitely not a side effect of his illness. It was rooted instead in the skills of his craft, which he continued to develop even during the stormy final year and a half of his life.”

Avoiding new speculation on van Gogh’s illness, the exhibition instead pulls together objects from key moments of the artist’s final years. The paintings — the majority of which come from the Vincent van Gogh Foundation — include his last self-portrait while in Paris (1887–88). The picture of the sullen artist in a blue shirt, rigidly clutching his brushes, presents a similarly removed figure as the van Gogh painted by Gauguin in 1888, prior to the ear incident. Van Gogh fashioned a different type of self-portrait when he emerged from the Arles hospital: his first work was a still life with a plate of onions that includes allusions to his health, from a pipe and a bag of tobacco to an empty absinthe bottle. Also pictured in the scene is Francois Vincent Raspail’s Manuel annuaire de la santé, a best-selling health guide that taught van Gogh to douse his pillow and mattress with camphor as a cure for insomnia. Soon after the onion still life, van Gogh painted Rey’s portrait as a gift to the doctor, depicting the mustachioed medical man in front of a dynamic backdrop of tendrils and red spots.

Van Gogh, however, returned to the hospital just three months after his discharge. He suffered another crisis after his neighbors in Arles sent their mayor a petition that deemed the artist a threat to the community. The petition, never publicly exhibited until now, was organized by the local grocer and had 29 other signatories. They claimed that van Gogh drank too much, was “not in full possession of his mental faculties,” and was “cause for fear to all the residents of the neighborhood, and especially to women and children.” Police had also apparently spoken with women who accused the artist of touching them inappropriately. Other documents translated and discussed in the exhibition catalogue are more sympathetic to his condition. Prior to the petition, the Reverend Louis Frédéric Salles had visited van Gogh and reported the following to Theo, the artist’s brother: “He has withdrawn into total silence, hides himself in his blankets and sometimes begins to cry without uttering a word. The cleaning lady told me that he refused to eat anything today … ”

Van Gogh eventually agreed to check into the asylum at Saint-Rémy de Provence, where he had a studio in addition to a bedroom. The exhibition features views from his stay there, including a busy drawing on wove paper of the overgrown garden seen from his first-floor bedroom and a painting of a wheat field with the Alpilles in the distance. After attendants caught him attempting to poison himself by eating paint, however, he was not allowed to enter his studio.

As is widely known, a wheat field is where the artist attempted to end his life. After more than a year in the asylum, van Gogh moved to Auvers-sur-Oise; in the following two months, he somehow acquired the 7mm pocket revolver of the owner of his lodging house. On July 27, he walked into a wheat field and shot himself in his chest. He survived but breathed for just two more days. He did not succeed in part because the bullet deflected off a rib, but also because he lost the revolver after that first attempt. A gun believe to be the artist’s weapon was found in a field in the area in the 1960s; now rusted, it’s on view in the exhibition. Experts say they can’t be completely sure of its authenticity, but the display of an item so evocative certainly spurs contemplation of the torment that must have been rushing through van Gogh’s mind.

On the Verge of Insanity: Van Gogh and His Illness continues at the Van Gogh Museum (Museumplein 6, Amsterdam) through September 25.