That is not quite the same as saying that precognitive dreams never happen, of course. But it is to say there is no practical need to imagine that they do in fact happen, which is very nearly -- but not quite -- the same thing.

There's probably no need to imagine they happen, but it's arrogant to say they don't given the weakness of alternative explanations. I think we both agree that the book is still open on what the cause of precognitive dreams is. My only point is that it's premature of skeptics to close the book, as I think some are prone to do.