Well my view isn't as simple, though I try to keep it that way. What works for me is to equate the astral planes to 3 levels that correspond to levels of our concsiousness. The first layer is the low plains. It coreisponds to the sub-conscious. The next is the middle plains : consciousness and the high plains : super-consciousness. Then I have another "level" that is below the low plains that I consider the abyss. Really it doesn't count as a layer because this realm doesn't correspond to any level of thinking. I think its impossible for a living being to enter this place and not advisable to do so either.
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