I've got into trouble before now for saying that I don't read fiction when I'm writing. It's true that all good writers were voracious readers first, and it's true that a surprising number of people say they want to write, without seeming to know that reading is a pre-requisite. I've had manuscripts to report on which made me wonder quite seriously if the writer had ever read a book (and no, most recent clients, if you're reading this, it wasn't you...). And it's not just for trainee writers: as I was saying in Alive, kicking and joining in the game, for the whole of a writer's life reading and writing are like the two halves of the human body which that life inhabits. We scoff (quietly, I hope) at the neophyte writer's fear of 'being influenced' - any writer worth their salt should want to be influenced by the greats, and by the contemporary masters/mistresses of their branch of the craft, whether it's Thomas Mann or Marian Keyes.
So when I pause a writing day for lunch and open a history book, am I failing to practising what I preach? It depends what you mean by 'when I'm writing'. The stage when I really can't read fiction is the first-draft stage and given the choice, that's as short as possible. If children didn't need feeding, and accountants and sisters didn't need telephoning, and I didn't occasionally need to take some exercise and go to the supermarket, it would be three or four months till I had 130,000 words on the page. And those words are raw, they're rough, they comes pouring up like lava, slow, burning and inexorable, from some underworld that I don't know my way round or have any maps for. One of the things I don't understand about that underworld is what makes which words appear, for what I want to say next. Voice is one of the things I get most excited about, but it's also one of the most mysterious. I love strongly-flavoured voices in fiction, but just because I love soaking in Ackroyd, James, Chandler, Woolf or Wodehouse doesn't mean I want to write like them. The trouble is, if I've been soaking, I can't help it. Not really like them, of course - I should be so lucky - but with that flavour, like a chopping board that you've sliced the onions on: whatever you do, don't start cutting up peaches on it. So all the other things you absorb from reading fiction are going to have to wait as well. Maybe it comes from a youth mis-spent writing parodies for the title-and-paragraph game, but that sponge-like tendency of my reader-writer's self is a bit of a liability but also one of my most valuable assets: one of my most cherished reviews of The Mathematics of Love said that 'its bilingual dexterity is only one of its several triumphs'.
Of course, non-fiction has a flavour too. In fact I sometimes get annoyed by the way that it's often talked about as if really great writing is only an issue in fiction and poetry, or these day's what's called 'imaginative non-fiction' (travel writing, memoir). Good prose is good prose. We could all learn a lot about the weight and balance of a sentence, about flexible, sophisticated grammar and syntax, about rhythm and sound, from the likes of Trevelyan, Kenneth Clarke, Roy Porter, or Peter Ackroyd in non-fictional mode. Elizabeth David wrote brilliantly (and goes very nicely with lunch), and so does Katharine Whitehorn. And an anthology of good journalism - from the Guardian Women's page, say - or of letters or diaries or speeches, can be a very good way of feeding your inner reader-writer without flavouring the chopping board too highly with a single scent.
Of course, for period voice it's those letters and diaries that are your first stop. Not that you'll write like them, either. I do a mean parody of the Paston Letters, but you couldn't write or read a whole novel like that. The 'authenticity' of our novels - in words or deeds - is only apparent. We write for our own time, and our voice is as much about England in 2008 as in 1471. What it can't be, though, is Los Angeles in 1927. It doesn't go with the armour.