Ernest Hemingway once said that “the reason people read novels,” Andrew O’Hagan reminded his book festival audience yesterday, “is to get the moral news.” Smart-suited and sharp-witted, O’Hagan is a suitable newsreader in that case. In his given hour he talked about dementia, the unrecognised creativity of too many Scottish women, visiting Afghanistan, child-bombers, our obligation to the migrants currently trying to escape Syria, the Scottishness of his imagination and his latest novel The Illuminations.

But no doubt festival audiences enjoy that morality in this case comes leavened with humour. And so we learned that Karl Lagerfeld once suggested to O’Hagan that he write Lagerfeld’s cat’s autobiography and that O’Hagan can’t write and receive emails on the same laptop in case Domino’s Pizzas send him a two-for-one offer just as he is writing about the “secret centre” of his character’s life. “It breaks the moment.”

But apart from giving us his own review of Benedict Cumberbatch’s latest play - “It’s a remarkable Hamlet for our generation.” – at the heart of his session was a recognition of the need for writer’s to experience the world and how, in turn, that experience can impact on the writer.

Thinking back to his first book, The Missing, which looked into the stories of some of the victims of Fred and Rosemary West, O’Hagan now believes “I was so young that I didn’t know how stupid I was.”

He couldn’t write that book now, he said because he understands the pain involved more. He described visiting the mother of one of the victims recently, her son’s room unchanged since he disappeared in 1985. “We just sat there in tears, the two of us.”

It would be strange if you didn’t come back from talking to British troops in Afghanistan or child bombers in Kandahar Prison unchanged, he reckoned. The anniversary of Hurricane Katrina reminded him of his trip to New Orleans. “I remember going there two days after the flood and seeing things that will never leave my mind.”

“In a good way, I hope,” he added. “It sharpens your pencil.”

At the end of Helen Castor’s talk on Joan of Arc the audience exited while being serenaded by Orchestral Manoeuvres in the Dark’s Maid of Orleans, one of the many iterations of the “mythic Joan” to be found in pop songs, movies and opera. Castor has been in search of the real woman behind the myth. What emerged from her research was a portrait of a young woman of “utter conviction”.

Could we say the same of our current Prime Minister? Actually, yes, according to Polly Toynbee and David Walker. They argued that the laidback, careless hoodie-hugger image we have been presented with over the years is far from the reality. Think “Thatcherite wolf” in charge of a government that is ruthless, determined and utterly ideological, one committed to ending the 1945 settlement and effectively turning the UK into a version of the USA. But with less public spending.

Walker and Toynbee presented their arguments in turn in the manner of the Two Ronnies, although in this case the script was clearly written by Samuel Beckett. Without the laughs.

What emerged was a vision of a dystopian Tory future, before veering into a collective mourning service for the state of the Labour party. Prime Minister Corbyn? They can’t see it happening. But Prime Minister George Osborne? All too scarily possible.