In a somewhat stark meeting room at Tate Britain, the curators of its forthcoming L.S. Lowry show, T.J. Clark and Anne M. Wagner, are attempting, at my request, to extol the artist's virtues to me. It's a complicated business. For one thing, I have the impression that they regard enthusiasm as infra dig. "I'll give it a shot," says Wagner, reluctantly. "But I don't think you're going to be convinced."

For another, they are apt to slip into the same art doublespeak that they use in their writing (both are academics), a language so ardently theoretical and verbose, it makes my teeth ache. "Of course he's a bad painter," says Clark, when I suggest that some critics consider Lowry to be more muddler than stylist. "He's a good painter, and a bad painter." And then, with overweening disdain: "British art in the 20th century has massively suffered from its inability not to be good."

OK ... so, let's talk about this good-bad painting, or bad-good painting, or whatever they want to call it. Why is Lowry worthy of another look? "Well, he is a master of mood," says Wagner. "His paintings of churches epitomize this. They have great delicacy and quietude. He can use grey unlike almost anybody I know. He is a painter for close-looking. Then there's his range of invention. "Bandstand, Peel Park" (a landscape from 1928) is an amazingly calligraphic painting, if you think of calligraphy as the dots and dashes of the application of paint. He can syncopate. Look at "Fun Fair at Daisy Nook" (from 1953), and ask yourself how he manages this hectic effervescence. It's so observant. I take the problems that he has set himself about the nature of the crowd as being immensely serious. This is a literary problem, a pictorial problem, a cinematic problem. It's a modern problem: What is the crowd? His solution is a formidable one. He is not kitsch. I would argue this with anybody. His paintings have an intense amount of feeling but I don't believe they tell you how to feel — which is a tremendous achievement, especially with this kind of material."