A free press is supposed to function as our democracy's immune system against such gross errors of fact and understanding. As Thomas Jefferson once said, "Error of opinion may be tolerated where reason is left free to combat it." So what happened? Why does our immune system no longer operate as it once did? For one thing, there's been a dramatic change in the nature of what philosopher Jürgen Habermas has described as "the structure of the public forum." As I described in the introduction, the public sphere is simply no longer as open to the vigorous and free exchange of ideas from individuals as it was when America was founded.
When errors of fact and judgment are no longer caught and neutralized by the nation's immune system, it is time to examine the problem and to work toward good health in our political discourse. In order to do this, we need to start paying more attention to new discoveries about the way fear affects the thinking process. And, in fact, recent advances in neuroscience offer new and interesting insights into the nature of fear.
For most of the last century, the human brain was studied almost exclusively in the context of accidents and unusual head injuries. Doctors would note the part of the brain taken out by the injury and then, after careful observation of strange behaviors, would slowly determine what functions had been controlled by the injured part. But now scientists are able to observe healthy brains in normal operation, measuring current, blood flow, and chemical activity that indicate which part of the brain is most active at a particular time.
New technologies in any field can have a revolutionizing impact. When Galileo used new and more powerful telescopes to study the heavens in greater detail, he was able to see the movements of the planets around the sun and the movements of Jupiter's moons around Jupiter in order to describe in compelling detail the comprehensive new model of the solar system first proposed by Copernicus. It was the new technology itself that empowered Galileo to describe a reality that was impossible to perceive so clearly until the new technology of the telescope made it possible.
In almost exactly the same way, the new technology called "functional magnetic resonance imaging," or FMRI, has revolutionized the ability of neuroscientists to look inside the operations of a living human brain and observe which regions of the brain are being used at which times and in response to which stimuli. Just as Galileo could suddenly see the moons of Jupiter, neuroscientists are now able for the first time to see the proper relationships among areas of the brain such as the amygdala and the hippocampus and the neocortex, to name only a few.
An entirely new understanding of the brain is coming forth, and one of the areas that has been richest in discoveries has to do with how we as human beings function in relation to fear. The implications for democracy are profound.
In a democracy, the common (if usually unstated) assumption is that citizens operate as rational human beings, reasoning their way through the problems presented to them as if every question could be analyzed rationally and debated fairly until there is a well-reasoned collective conclusion. But the new research demonstrates that, of course, this is not the way it works at all.