"Well, [biographer Richard] Holmes is the great master of the quest, of the search. But there is the moment in Footsteps, when he is following [Robert Louis] Stevenson and finds himself on the bridge he thought Stevenson crossed, and then sees another bridge a few hundred yards away and realizes it was the other one. The point is that you can do a parallel journey, but however close you feel to the person—you've held his or her letters, seen what's been crossed out, got the journals, you've been in touch, as it were—you've got to be careful of not putting on the same clothes your subject did, of not eating the same thing. A good day's work, I think, is when at the end of the day I've written something I didn't know at the beginning.
I think I'm two people—the researcher and the writer. The researcher spends quite a lot of time going abroad, working in libraries, seeing letters. I sometimes turn to the writer, who is doing nothing at that point—who is sleeping!—and I say, Do you want this bit about [George Bernard] Shaw bicycling? And the writer doesn't know. He says, You're the researcher, you decide. So the researcher thinks, Well, that's really not important. And the researcher is always longing to be writing, getting on with the actual problem we created. Then the writer takes over, shuts the door to the world, and kicks back on this researcher who was traveling the world, meeting people, making discoveries, and he says, Why the hell is there no documentation here about Shaw and the bicycle? This part of Shaw's life is exactly about how things were happening more quickly, whereas before he was on foot."
(michael holroyd to lisa cohen, from "the art of biography no. 3," the paris review summer 2013)