Ken Wilber discusses mystical experiences in an interview with Pathway magazine:
Pathways: Is this realization an all-or-nothing affair?
Ken Wilber: Not usually. It’s often a series of glimpses of One Taste -- glimpses of the fact that you are one with absolutely all manifestation, in its good and bad aspects, in all its frost and fever, its wonder and its pain. You are the Kosmos, literally. But you tend to understand this ultimate fact in increasing glimpses of the infinity that you are, and you realize exactly why you started this wonderful, horrible Game of Life. But it is absolutely not a cruel Game, not ultimately, because you, and you alone, instigated this Drama, this Lila, this Kenosis.
Pathways: But what about the notion that these experiences of “One Taste” or “Kosmic Consciousness” are just a by-product of meditation, and therefore aren’t “really real”?
Ken Wilber: Well, that can be said of any type of knowledge that depends on an instrument. “Kosmic consciousness” often depends on the instrument of meditation. So what? Seeing the nucleus of a cell depends on a microscope. Do we then say that the cell nucleus isn’t real because it’s only a by-product of a microscope? Do we say the moons of Jupiter aren’t real because they depend on a telescope? The people who raise this objection are almost always people who don’t want to look through the instrument of meditation, just as the Churchmen refused to look through Galileo’s telescope and thus acknowledge the moons of Jupiter. Let them live with their refusal. But let us -- to the best of our ability, and hopefully driven by the best of charity or compassion -- try to convince them to look, just once, and see for themselves. Not coerce them, just invite them. I suspect a different world might open for them, a world that has been abundantly verified by all who look through the telescope, and microscope, of meditation.