The thought that kept running through my head while I was reading this, is whether sometimes believing something untrue, will eventually make it true. And I don't mean it in the "might makes right" or "history is written by the victors" sense, but rather literally that (in this case a fear) might make something a reality. So, for instance, the fear of death, might make immortality (or something close to it) a reality. In that sense, believing in a falsehood is useful. For example, if we all lived like the feet-on-the-ground ancient Cynics, we would all still be living like the ancient Cynics. Not very useful! I guess what I'm trying to say might relate a lot to William James' argument(s) in his Will to Believe.