Jonathan Swift left £11,000 -a fortune, and not a small one - to found a mental hospital in Dublin, commemorating or puncturing this charitable act in his “Verses on the Death of Dr Swift”:

The fools and mad of Ireland loom large in Sebastian Barry’s work. Thomas Dunne, the central figure of his best-known play, The Steward of Christendom, is one of the mad, babbling about green fields as he lives out his days in a Dublin county home (not the one Swift paid for). Barry’s novel The Whereabouts of Eneas McNulty concerns a fool: Eneas is an innocent, blundering through the 20th century, exiled for breaking a patriotic code he doesn’t grasp. The characters in these stories are exiles, maybe not literally, as Eneas is, but cut off from family or country - cut off, most of all, from history, bound up with a past that Ireland would rather forget. Both Thomas Dunne - who really existed, and was one of Barry’s ancestors - and Eneas McNulty are Catholics who join the British-run police force, and after independence are marked men. Willie Dunne, the hero of Barry’s novel A Long, Long Way, shortlisted for the Booker Prize in 2005, is an Irish Catholic who dies for Britain in the First World War. Many of Barry’s works are woven together by recurring characters or places - Willie is Thomas Dunne’s son, and figures as a boy in The Steward of Christendom; Thomas’s daughter, Annie Dunne, gives her name to a novel of 2002. The cumulative effect is to suggest not simply that here is another way of looking at Irish history, but that here is the best way: that what defines Ireland most truly is what it has shut out, or shut away. Which may have been what Swift was getting at.

The heroine of The Secret Scripture is Roseanne Clear - who, at 100 years old, is reconstructing her life in notebooks she hides under the floorboards of her room in an asylum in Roscommon. Her story begins in Sligo - Yeats territory, the birthplace of many of modern Ireland’s myths - where Roseanne’s family is cut off from everyday life by Presbyterianism, poverty and her mother’s illness (she, too, ends in the madhouse). Roseanne is set further apart by her uncommon beauty, which makes her an object of suspicion to the local priest, Father Gaunt. She finds happiness with Tom McNulty, but an accusation of adultery pushes her into isolation again, abandoned for years in a shack by the sea, her marriage annulled. Mysteriously, she gets pregnant; when the baby is born and immediately disappears, she is declared mad, and her 6o-year exile from the world begins. Her narrative is interwoven with shorter passages from the “commonplace book” of her psychiatrist, Dr Grene, whose sympathetic speculations about Roseanne’s past mingle with his own griefs.

Barry writes “heightened prose”, at once high-flown and earthy, a plain vocabulary juggled into picturesque cadences and images. When this works, as in The Steward of Christendom and Eneas McNulty, the effect is bewitching; but it can become irritating. In The Secret Scripture, the difficulty of the style is compounded by Barry’s failure to give his two narrators sufficiently distinct voices - Dr. Grene was educated in England, and at one point says that nobody could mistake him for an Irishman, whereas he is at times almost stage Irish. The book is also marred by a self-consciously literary quality, manifested in Roseanne’s improbable attachment to Sir Thomas Browne’s Religio Medici and the predictable unreliability of the narrators. In an instance of Barry’s interweaving, Roseanne’s husband is Eneas McNulty’s brother: a brief appearance by Roseanne in the earlier book is retold here, but with significant variations. As the novel progresses, her clear-cut version of events is contradicted by documents that Dr Grene discovers: her father, whom she says was a gravedigger, is alleged by Father Gaunt to have been a policeman; a happy memory of her father testing Galileo by throwing hammers and feathers from a church tower, to see which fall faster, is transformed into a retelling of his death, tarred, feathered and beaten with hammers. But then this version of events turns out to be a fabrication of Dr Grene’s - an inexplicable one, as he has not yet encountered Roseanne’s original story.

The intention seems to be to steer the reader away from a stereotyped understanding of Roseanne’s life towards a sense of the untidiness and irresolvability of history and memory. At the same time, the novel does embrace some stereotypes - the misogynistic, sex-obsessed Catholic priest, for one - and towards the end accelerates uncomfortably towards a denouement that ties loose ends and adds a twist that is less ironic than melodramatic (it is also, unfortunately, guessable). For all its mysteries, hesitations and poetry, The Secret Scripture is, finally, a little too pat.