First, a disclaimer. Throughout my art-history education, which began in the 1960s and was probably typical, pre-twentieth-century sculpture was evaluated much as it had been since the Renaissance, which is to say in formal terms, the purity of its planes and contours competing with painting’s reliance on surface and color. I came to know, at least intellectually, that perceptions and judgments are indelibly affected by the conventions and values of our time, and assumed that,...