Let me explain.
He’s making an argument against neuro-eliminationism, and doing so by way of interpreting Ben Libet’s perplexing results. These are the experiments that go roughly like this. We monitor the brain waves of a person who’s asked to perform a simple action, like flip a switch. What we find is that there’s a blip in the brain waves some hundreds of milliseconds before the person has a conscious intention (indicated, I believe, by saying so) to flip the switch. What’s up?
We don’t know.
So far as I know, no one really does, though lots of philosophers have had lots to say about these results. And I don’t find those discussions illuminating. Eliminativists read the results one way, anti-eliminativists read them another way. So what?
If we don’t understand what’s going on, in neural terms, how can metaphysical discussion be meaningful? It’s rather like discussing the motions of the planets and stars without realizing that the earth moves about the sun and that, e.g. the Morning Star and the Evening Star are, in fact, the same being, the planet Venus.
There’s a lot of discussion like that these days. Some of the nonsense may well be elucidatory, but most of it is just plain old garden variety nonsense. While there’s no way to make a clear distinction between the two, I do think that if one has expended the effort to become familiar with the empirical territory—in this case, neuroscience—the—one is more likely to spout useful nonsense. So, don’t just read the philosophers or the pop neuropsych, read the scientific literature, at least at the level of Science or Nature, if not the more specialized literature, and find yourself a bench scientist who’s willing to discuss these things with you. As I said a couple of months ago, in a discussion of the philosophical excesses of Levi Bryant, call the plumber.
It's worth remembering that 150 years ago the French Academy stopped publishing work on language origins because the speculation far exceded available evidence and reasonable models. Sometimes we have to admit that we just don't know. No matter how important the subject is, if we don't know, then, really, we don't know. Further discussion is gibberish.