Florence’s missing link

Want to be depressed? Read up on Florence in the fifteenth century. It’s not just the overabundance of outsized talent. At one time or another, centers like Amsterdam, Rome, Paris, and New York have boasted comparable rosters. It’s the unmatched level of ambition, innovation, curiosity, self-discipline, and imagination its denizens brought to bear in remaking their world. Some of their endeavors—Brunelleschi lofting a dome over the cathedral without centering, for example—were the moonshots of their day, efforts that involved not just realizing a vision but inventing, every step of the way, the means of doing so. They revered their classical heritage, seeing the past as a bottomless wellspring of instruction. Early on, Brunelleschi and Donatello moved to Rome to study, respectively, ruins and statuary, then used that knowledge to revolutionize architecture and sculpture upon returning to...