Paul Nash at Dulwich

At Dulwich Picture Gallery you'll find no anguished scribblings or pickled whatnots in jars, just fine pictures by Rembrandt, Poussin and other luminaries. Walking in to the place one is transported back to an age before Isms, and in context the work of Paul Nash - some of it now a century old - seems almost outrageously inventive.

This is the first decent Nash exhibition since the show at Tate Liverpool in 2003, and he has nothing like the profile he deserves. I suspect that I'm not alone in having grown up believing that Turner was the last British painter that ever lived. I learned about French Impressionists, German Expressionists and American Abstract Expressionists. We had Lowry and Henry Moore.

Yes, things have changed since then. Whiteread, Hirst and co demonstrated that you could both live in Britain and create great art. Yet the work of previous generations has continued to be ignored; Nash, who was both a gifted and committed painter and an innovator, has until now languished in obscurity.

The current show may a bit testing thematically, but at least the pictures are on the wall, and you can see what made Nash both fascinating and highly successful. In the 1930s, when everyone was busy taking sides - Right vs Left, Representation vs Abstraction - he resolutely followed his own path. Like Eric Ravilious, his pupil, Nash found a new way of painting the English landscape, but whereas Ravilious combined his technical mastery of watercolour with a seer's vision to create images of haunting beauty, Nash toyed with the landscape to suit his symbolic needs.

Sometimes the effect is puzzling. Eclipse of the Sunflower, for instance, leaves me wondering if I'm missing something. On other occasions it is astonishing; Pillar and Moon (at the top of the post) is the kind of painting that keeps you awake at night.