Is it possible for a writer to describe, as from the inside, an experience that he has never himself had? Can he, for example, describe what it is like to be delirious without ever having been delirious (and remembering it)? And if he does describe it, is his description worth anything; does it convey any real knowledge or insight to the reader?

Anton Chekhov (1860-1904), who was a doctor when delirium must have been much more common than it is today, describes both its exterior and interior, objectively and subjectively. In the story “The Teacher of Literature,” for example, Ippolit Ippolititch, a teacher of history and geography at a local school, dies of erysipelas of the face after a period of delirium.

Ippolit Ippolititch is a completely unimaginative man who never in his life says anything other than what everyone already knows. When he eats, for example, he solemnly declares that, “Man cannot live without food.” When a colleague marries, he says to him, “Hitherto you have been unmarried and have lived alone, and now you are married and no longer single.”

Even when delirious, he is incapable of other than the dullest banalities. Just before he dies, he mutters, “The Volga flows into the Caspian sea . . . Horses eat oats and hay.”

There really are people as dull as Ippolit Ippolititch. Sometimes you hear them on trains; the volume of people’s voices not, alas, always being proportional to the interest of what they have to say. I know of a man whose reaction on first seeing Versailles was to wonder how they kept it clean; his wife used to turn up the radio to drown out what he was saying. As Chekhov would have known, it was tragic for them both.