“Human life, Borges said, is a cascade of possible directions, and we take only one, or we perceive that we take only one—which is how novels are written, too. You start with a blank page, and the first word opens up possibilities for the second word. If your first word is Call, those second two or three could be a doctor or it could be me Ishmael. It could be Call girls on Saturday nights generally cost more than . . . The second sentence opens up a multitude of third sentences, and on we go through that denseness of choices taken and choices not taken, swinging our machetes.”