LEWIS'S FIRST NON-FICTION book, The Caliph's Design (1919) was about art, as was this, his last (1955), but none of the many in-between--he did, however, write a good many essays about art in general and painting in particular from the 1920s through the late 1940s, and served a distinguished stint as art reviewer for the Listener until blindness forced him to resign.
Lewis always writes about painting as a practicing painter himself (here, as a formerly practicing painter), as an insider--important to remember, since he often sounds cantankerous about innovation and experiment in the arts, as this book's title suggests. But Lewis himself was a powerful innovator as a painter in the earlier part of his career, and he saw what made Picasso the greatest painter of his generation; it's not as though he was clamoring for the return of Constable and Gainsborough. He could, though, be as curmudgeonly as any New Criterion-type, or as Tom Wolfe in The Painted Word, when he thought lofty talk of innovation and experiment was serving as a smokescreen for charlatanry or thinness of talent.
Had he lived another ten years, what would he have made of Warhol? Or, much later, Damien Hirst? Hard to guess--all we know is that his take would have been dauntingly original, whatever it was.
Herein lies the Lewis Conundrum, also exemplified by his long essay "The Diabolical Principle," his no-holds-barred assault on various self-appointed avant-gardistes of the late 1920s. He sounds like a conservative when he's attacking artistic innovation and experiment--but he was as open-minded as anyone about genuine innovation and experiment, right up to the end (he admired Francis Bacon, for instance). When he thought the innovators were merely posing, though, or finding a way to disguise the weakness of their technique, or essentially marketing themselves...then his wrath knew no bounds.