Carcanet press is a benefactor of mankind, or at least, the reading public, or that bit of it which rates Muriel Spark as the genius she was. Last year, it reissued her extraordinarily insightful writing on Mary Shelley, which did justice to the lady’s originality, though Shelley didn’t come terribly well out of it. Earlier this year it published a selection of her splendid essays and journalism, The Golden Fleece, edited by her companion, Penelope Jardine.Now we have a reissue of The Essence of the Brontës, her essays on the family and her selection of their letters. Anyone who loves Muriel Spark (viz., any right thinking reader); anyone who loves the Brontës (and is up for a little judicious iconoclasm); anyone who relishes the spectacle of one literary genius anal