Edward Munch is most famous for his painting ‘The Scream’. He was a tortured soul by his own admission, and would struggle with alcoholism and mental illness later in life. He once wrote, “Illness, insanity, and death were the black angels that kept watch over my cradle and accompanied me all my life.” His most famous painting, The Scream, has inspired countless depictions of pain—including the famous Scream mask.

Etched into the paint of one of the most famous paintings in the world, a haunting eight-word sentence has been a mystery to art historians for over a century. The sentence reads, “Can only have been painted by a madman.” The mysterious statement—clearly added sometime after the painting’s debut in 1893—was long thought to be added either by a disgruntled onlooker or perhaps the artist himself.

The century-old debate has finally been settled by modern technology. Using infrared photography to compare handwriting to Munch’s letters and journals, experts at the National Museum of Norway claim the words are in fact the artist’s own. Read more about the discovery here.