The point he's trying to make is that science can only solve problems that are accessible to investigation by the scientific method. Some problems don't meet those criteria, but that doesn't stop neuroscientists, and popsci fans from imagining that everything can be explained by the almighty neuron. It's a fascinating but sad new chapter in science. Read anything by John Searle or Daniel Dennett (probably the two most famous philosophers who think in this way) to get a sense of what I'm talking about. When you and your spouse are in an argument, or a relative dies, or you're trying to create a new piece of art, the last thing you need is for someone to tell you that you lack agency. Yet that's where we find ourselves in modern neuroscience. It's banal and pedantic.