As Michelangelo was finishing his famous sculpture David, a powerful patron appeared below the ladder on which he was standing and suggested that perhaps the nose was too thick. The artist came down and stood beside his patron to assess things. When the man looked away, Michelangelo quickly snatched a handful of dust and ascended again, pretending to tap his chisel and letting the dust slip between his fingers. Having altered nothing, he climbed down once more and waited for an opinion. The patron was delighted: “Oh, that’s much better! Now you’ve really brought it to life.” The anecdote is...