John Steinbeck's Journal of a Novel is a book I've kept on every desk I've written at for the past 10 years. I've rarely opened it when I'm not working on a book, and never when I'm writing well. But on those days when the engine room of a first draft feels claustrophobic or static, when the words have turned brittle and the whole endeavour seems either pointless or ridiculous, that's when I'll reach again for this idiosyncratic one-sided correspondence which comes together to form a rare map of a literary mind at the point of creation.
Every morning between 29 January and 1 November 1951 Steinbeck, "like a pitcher warming up to pitch", would begin his day's work by writing a "letter" to his editor and friend Pascal Covic on the left-hand pages of a notebook, the facing pages to be filled with the first draft of his masterpiece, East of Eden.
The result is a three-way correspondence between author, book and editor: a privileged glimpse into Steinbeck's writing at both its most mechanical and philosophical.
Steinbeck was 49 when he began East of Eden, simultaneously aware of what he had achieved and might yet achieve. Perhaps it's this self-awareness that lies behind the undertow of trepidation. Anyone who has embarked on a writing project of any scale will recognise the mix of exhilaration and fear: "It is amazing the terrors, the magics, the prayers, the straightening shyness that assails one."
The letters evolve from unpromising worries into gems of literary wisdom. "A chapter should be a perfect cell"; "once all the form of a book gets in your bones, then you can only work on the story and the rest comes right", "How odd – that sadness can turn to gold."
Journal of a Novel repeatedly guides me in the writing of fiction and, perhaps more importantly, reminds me why it should be written at all. "It is the duty of the writer to lift up, to extend, to encourage," Steinbeck writes. "Great writing has been a staff to lean on, a mother to consult, a wisdom to pick up stumbling folly, a strength in weakness and a courage to support sick cowardice."
The joy of Journal of a Novel is to witness the imbrication of Steinbeck's writing life in his everyday life. A passage about his characters or his choice of pencil will be followed by details about the building of a new desk, or a new red rug bought for the house. Such free wandering allows for some surprisingly astute comments away from the subject of writing.
But then, always shadowing such thoughts, is the novel, "waiting and working kind of like a fermenting mash out of which whiskey will be made eventually". "Now," he signs off on 16 March, "it is time for me to go to work."
When he does, he leaves you feeling the same.
Owen Sheers's 'White Ravens' is published by Seren, and his 'A Poet's Guide to Britain' by Penguin Classics