ALL DOWN DARKNESS WIDE, Seán Hewitt’s splendid new memoir, is haunted by ghosts. “Everything, once you start to look,” he observes, “is haunted.” There are the ghosts of a Catholic faith he abandoned; the ghost of his dead father; the ghost of the gay Jesuit poet Gerard Manley Hopkins, his poetic mentor; the ghost of the once grand city of Liverpool, “dragging itself up out of its own grave”; and the ghost of Hewitt’s closeted gay youth. … But most of all, …