It’s a pattern as old as time. Somebody makes an important scientific breakthrough, which explains a piece of the world. But then people get caught up in the excitement of this breakthrough and try to use it to explain everything.

This is what’s happening right now with neuroscience. The field is obviously incredibly important and exciting. From personal experience, I can tell you that you get captivated by it and sometimes go off to extremes, as if understanding the brain is the solution to understanding all thought and behavior.

This is happening at two levels. At the lowbrow level, there are the conference circuit neuro-mappers. These are people who take pretty brain-scan images and claim they can use them to predict what product somebody will buy, what party they will vote for, whether they are lying or not or whether a criminal should be held responsible for his crime.

At the highbrow end, there are scholars and theorists that some have called the “nothing buttists.” Human beings are nothing but neurons, they assert. Once we understand the brain well enough, we will be able to understand behavior. We will see the chain of physical causations that determine actions. We will see that many behaviors like addiction are nothing more than brain diseases. We will see that people don’t really possess free will; their actions are caused by material processes emerging directly out of nature. Neuroscience will replace psychology and other fields as the way to understand action.