Art: Spectator Painter

John Sloan, who died last summer at 80, was one of America's best painters. This week Manhattan's Whitney Museum opens a retrospective show of his work that brings Sloan vividly back to life.

In his old age he was a bony man who peered warmly at the world through spectacles, talked much, and puffed a pipe for punctuation. "I'm birdlike, yes," he would say, "but so is the American eagle." He painted steadily until death, because that was his chief joy and also because he knew he still had a lot to learn about painting. A born teacher, he never stopped studying:...