The only one among those with whom I am familiar is Sam Harris. I like Sam’s work. He and I don’t agree about everything but generally about the important parts. That said, I haven’t read that specific book.

Like another commenter said and I concur, I’m not much into “spiritualism.” It’s a trigger word for me, which evokes a lot of hogwash and superstition. Maybe it doesn’t do the same for others and in context may have nothing to do with it.

Not to put too fine a point on it, I am not one to dissuade others or to be judgmental about maintaining an awareness, concern and respect for “meta” aspects of life. Emotional things, connections to other human beings, etc. Human beings have brains and there’s nothing inherently rational about the way we interpret their workings. It’s fine. I ponder the complexities of life and the pursuit of happiness as well, I imagine we all do. Should someone want to refer to that as “spirituality,” fine. You can call it “banana” if you want to, I’m not the semantic police.

Where I draw a line personally as at the moment when superstitious “faith” or mysticism enters the picture.

When consuming literature like this, I think it’s best to keep a skeptical lens and always be asking whether you’re replacing a house of cards with a bridge of toothpicks. If the new foundation is just as flimsy as the old one, it’s not a foundation at all. On the other hand, if the work helps to organize thought without introducing new ghosts, it’s probably just a matter of taste after that.