Those who study Charles Dickens, or who keep up the great cult of his admiration, had been leading a fairly quiet life until a few years ago. The occasional letter bobs to the surface, or a bit of reminiscence is discovered, or perhaps some fragment of a souvenir from his first or second American tour. The pages of that agreeable little journal The Dickensian remained easy to turn, with little possibility of any great shock. At least since The Invisible Woman, Claire Tomalin’s definitive, 1991 exposure of the other woman in Dickens’s life—the once enigmatic Nelly Ternan—there hasn’t been any scandal or revelation.

And then, in late 2002, The Dickensian carried a little bombshell of a tale: it seemed that in 1862, during Fyodor Dostoyevsky’s visit to London, he had met Dickens. And not only met him but elicited from him the exact admission that we would all have wanted the great man to make. Here is how it goes in En­glish, as summarized by Dostoyevsky in an 1878 letter to a certain Stepan Dimitriyevich Yanovsky. According to this, the two men met at the offices of Dickens’s own personal magazine, All the Year Round. And here’s how the confessional session went:

He told me that all the good simple people in his novels, Little Nell, even the holy simpletons like Barnaby Rudge, are what he wanted to have been, and his villains were what he was (or rather, what he found in himself), his cruelty, his attacks of causeless enmity towards those who were helpless and looked to him for comfort, his shrinking from those whom he ought to love, being used up in what he wrote. There were two people in him, he told me: one who feels as he ought to feel and one who feels the opposite. From the one who feels the opposite I make my evil characters; from the one who feels as a man ought to feel I try to live my life. Only two people? I asked.

So convenient and neat was this package that many first-time recipients endorsed it without even bothering to...