This is one of those books that just came along at the right time. It was a significant part of my intellectual journey as it demonstrated that there were things beyond easy scientific explanation - provided you could believe Shirley Maclaine was not fibbing. My view was (and is) that she was telling of real experiences she had had.
She certainly put herself out on a limb writing as she did.
It is in no sense a mystical book but it does undermine the position of the naive realists who judge that what you can see and measure is all that there is.