Then there is Diane Arbus. In the weeks leading up to her suicide, she too was doing work that she considered especially fine--this being her photos of the mentally retarded, published in the book "Untitled." As she said at the time, "Finally what I've been searching for." These pictures were a departure, a culmination, a new beginning (or so it seemed). Then a few days later, Arbus was dead.

What's going on here? It's more than a little uncanny. As Wendell Berry once said: "To go in the dark with a light is to know the light. To know the dark, go dark." Both Plath and Arbus knew the dark, but this knowing came at a massive price. The dark stayed dark. Forever. Some artists--not all--do not survive the hero's quest. Maybe, when the moment comes, they lack the requisite "ego strength" to re-compose after the decompensation that a certain category of art requires. Or else: once they achieve genius, the question becomes: Where do I go from here? Having reached the top of the mountain, there is nothing left but the descent, and the idea of descending is simply intolerable, ultimately depressing.

Such a model would not apply to all artists, of course. Ken Kesey, to take one example, knew that "Sometimes a Great Notion" was his masterpiece (not, by the way, the decidedly inferior "One Flew Over the Cuckoo's Nest"). After completing it, he never wrote another novel. Still, he survived. The question is: Why didn't Plath and Arbus?