Portrait of a true Renaissance man

BECAUSE Walter Isaacson has made a cottage industry of writing about Renaissance men, it is no surprise, really, that he has finally landed on a subject from the actual Renaissance.

Like the other idols in Isaacson's gallery of polymaths and visionaries - Albert Einstein, Benjamin Franklin, Steve Jobs - Leonardo da Vinci was born with extra bundles of receptors, attuned to frequencies that his peers could not hear and capable of making connections that no one else could see, especially between the sciences and the humanities.

There is a significant difference, though, between Leonardo da Vinci and Isaacson's previous biographies. His other geniuses left behind bountiful source material about the lives that they led. Leonardo did not.