No article on Oliver Sacks, the neurologist and bestselling author, should ever be published that does not contain at least one tiny case story, no matter how brief it is. Of course one that comes from Sacks: You can listen to him on YouTube telling the case of a blind woman who, at the age of ninety-five, suddenly suffers from hallucinations. She sees people in oriental clothes running up and down stairs, a smiling man, animals, a building, snow. It was, said the woman, like a movie, but a boring movie. And of course she worries about the pictures.

She wanted to know from Oliver Sacks whether she had gone mad. “Everything is in perfect order,” he replied, smiling, almost happily, with his inimitable English accent, which he has retained even though the 1933 Oxford-born man has lived in New York for almost half a century. She has the "Charles Bonnet Syndrome", a neurological disorder that leads to deceptive perceptions and which is named after the famous Swiss naturalist. And then Sacks, the great narrator, makes a decisive gesture: he sits up in the chair as if a medal was pinned to his chest. "Tell all the nurses," he says of the old lady in this pose, "that I have Charles Bonnet Syndrome."

This is the great secret of Sacks' universe: He regards diseases, deviations, and disorders as awards that he is pleased to have discovered, like a researcher who tracks down and describes another species in the dark deep sea. His work as a neurologist and psychiatrist at various universities and hospitals in the United States is closely linked to writing. His first work "Awakenings" made him famous in 1973, which deals with the mysterious sleeping sickness; it was filmed in 1990 with Robert de Niro, the German title is "Zeit des Erwachens". Sacks has researched and written about migraines, about "the man who mistook his wife for a hat", about the effects of music and, most recently, about hallucinations. This Tuesday, the man of letters among the medical profession will be eighty years old.