Some of your book selections might not be thought of as traditional biography. What ties them all together?

These five all stretch the genre of biography. I’m interested in the frontiers of biography and where the genre can go. It’s a very old genre. There are traditional ways of doing biography, and every age had its own format. The Victorians had their two-volume life and letters, usually quite hagiographical. “Full-scale biography” was the admiring term, and it led to larger and larger biographies which tried to incorporate every factual detail – to be the last word on a life. But the examples I picked move the genre on from the traditional vast tome, which is highly sequential – pedigree to grave.

There is no such a thing as a complete life. It was a fiction of the marketplace. If you look at your own life and try to tell the whole truth about it, you can’t. There’s no way. I’m in sympathy with those who question it. For instance Janet Malcolm, in Reading Chekhov, quotes at length from The Lady With the Dog, a story set in Yalta. Malcolm is proposing that there is no way that we can know Chekhov – he was a reserved person – but that there is a kernel of his inward life that she can get at. She quotes Chekhov writing about one of his characters, but implies that this is Chekhov’s own voice:

“He had two lives: one, open, seen and known by all who cared to know, full of relative truth and of relative falsehood, exactly like the lives of his friends and acquaintances; and another life running its course in secret. And through some strange, perhaps accidental, conjunction of circumstances, everything that was essential, of interest and of value to him, everything that made the kernel of his life, was hidden from other people; and all that was false in him, the sheath in which he hid himself to conceal the truth ­– all that was open. And he judged of others by himself, not believing in what he saw, and always believing that every man had his real, most interesting life under the cover of secrecy and under the cover of night. All personal life rested on secrecy.”

I was delighted to come across this, as I began writing about TS Eliot with a similar assumption – that there was an inner life somewhat at variance with a strong façade.

So what is the essential purpose of biography? Is it to document a life or to explore that inner kernel?

That’s the question. If it’s a biography of a public figure active on the stage of history, then you will want to document. And documentation is part of it. If a poet writes a sonnet, it’s part of the intensity of that form that there are very strict rules. And there are strict rules of biography – you have to authenticate facts, you have to include that detailed back-matter to tell the reader where a fact comes from. On the other hand, documentation alone is inadequate for the kind of biography that interests me. You need some shell of the public life, but the deep matter of the biography is the “private life” that Henry James talks of – he meant the writer’s life, the inward life.

And although it’s what one aims for, it’s impossible. The honest biographer would admit there’s no way you can fully reach that. It dies with the person. One of the most succinct statements of that is in a letter of Emily Dickinson’s. She said that “abyss has no biographer”. And that’s the problem. But not to attempt the abyss seems to me to miss the point.

And why should we read biographies at all? What is the reader’s harvest from them?

For me there is a fascination with character. You could say that novels are more enjoyable reading, but I’m interested in the authentic. And with literary figures there is always an interest in the work, in what is permanent in a life. For me that was always a starting point. I was captivated by a work, and wanted to understand how it came into being. TS Eliot famously posited the separation of the man and the work, but I think that was Eliot’s blind, his work is in fact quite autobiographical. And obscure lives are potentially as interesting as famous lives, except that with obscure lives the chances of material are slimmer – there have to be diaries or letters.

Above all there is curiosity, and a detective aspect to biography that is inescapable. Otherwise you’re just plodding along. You are fascinated to know how this life came to be. What is the plot of this life? There will be a plot imposed by circumstance but also, if it’s an imaginative person, they will have some conception of a life in mind. There’s something that Yeats says in A General Introduction to My Work: “The poet is not the muddle that most of us are when we sit down to breakfast. He's reborn as an idea, something intended, complete.” He’s saying that there’s a conceived life. And that’s why I’ve added Eliot to the list. More than any of the other subjects that I’ve picked, Eliot has a predetermined pattern, which is the spiritual journey, the soul’s journey. And that’s why Dante is so important to him.