The more we understand about the world and especially our brains, the more it seems that our decisions are determined by forces — our genes, our neurons, our upbringing, for example — that are beyond our control. And yet we experience making choices. In “The Benefits of Binocularity,” Erik Parens explains the “better way to go about trying to understand what sorts of beings we are is to see ourselves as both free subjects and as determined objects, and to accept that we aren’t wired for seeing ourselves in both ways at once. Using either lens alone can lead to pernicious mistakes.”