Incognito: The Secret Lives of the Brain

by David Eagleman

The crux of the question is whether all of your actions are fundamentally on autopilot or whether there is some little bit that is “free” to choose, independent of the rules of biology. This has always been the sticking point for both philosophers and scientists. As far as we can tell, all activity in the brain is driven by other activity in the brain, in a vastly complex, interconnected network. For better or worse, this seems to leave no room for anything other than neural activity—that is, no room for a ghost in the machine. To consider this from the other direction, if free will is to have any effect on the actions of the body, it needs to influence the ongoing brain activity. And to do that, it needs to be physically connected to at least some of the neurons. But we don’t find any spot in the brain that is not itself driven by other parts of the network. Instead, every part of the brain is densely interconnected with—and driven by—other brain parts. And that suggests that no part is independent and therefore “free.”