What is the point of fiction if not to expand horizons?

While Ian McEwan’s recent piece in the Guardian is not expressly termed a treatise on the value of art, it is hard to see it otherwise. What is the use of fiction, what can a novelist tell us of, ‘why the Industrial Revolution began, or how the Higgs boson confers mass on fundamental particles…?’ he asks. At the heart of this modern day ‘defense of poesy’ is McEwan’s devotion to realism: it is realism that falls last to ‘the icy waters of scepticism’ and it is realism that saves him from it. He gives an account of how his thirteen year-old self, so overcome by the description of the 1900 heatwave in The Go-Between, leaves his seat in the library to check the archives of Punch. He discovers the magazine and its treatment of the searing heat exactly as the writer described.

This is a moving account but critically disturbing. Art is about more than ‘how the worlds of fact and fiction can interpenetrate.’