“She is older than the rocks among which she sits.” Oscar Wilde couldn’t get those words out of his head and they drew him compulsively to the Louvre. If Walter Pater had never written them, would there be huge crowds today, snapping photos of Leonardo da Vinci’s Mona Lisa? That is just one example from Pater’s book of how art writing matters – something that inspires me in my career every day.

It’s a small volume of nine short pieces on what must have seemed an eccentric selection of artists, including the first published article on Botticelli, then virtually unknown. Before publication in 1873, Pater added a conclusion that got him into trouble. He argued that “the love of art for art’s sake” was valuable in itself, without ulterior motive, serving no one’s special interests.

That message might still get a writer into trouble, not least in museums that are now asked to serve all manner of clashing interests: education, social engineering and, above all, profit-making. And yet the greatest good that may happen in museums is what Pater’s essays constantly encourage us to do: to see the museum object without categorising or classifying it, but just letting it stir our imagination to roam wherever it will. It’s that freedom of imagination that might be able to change the world.

Liz Prettejohn is a professor of history of art at the University of York