The author paints an image of conflict between himself on lsd, and himself off lsd. Himself the perceiver, and himself the analyzer. I don't think these are integral to the experience. He mentions perceptions like '...the notion of “teetering” was meaningless too—I was on both sides of the precipice at once'. I can identify this dissolution of boundaries and commingling of opposites in my own experiences. If you try to interpret the experience in terms of dichotomies and distinctions, your words will be inadequate to describe it. The inadequacy of such understanding might agitate you. There is something here for the analytical mind to gain too: learning to coexist with uncertainty, doubt, paradox, and mystery and yet keep going and keep analyzing. You don't have to lose your head on LSD, but you'll find in the deepest places that there is no distinction at all between the analyzer and the dreamer.
In regular old life, too, I believe that distinctions, drawing a line between 'this' and 'that' can be as much a handicap to understanding as an aid. Distinctions tell things apart, but unity and continuity are as integral to reality as difference and change. The wholeness of being engendered by psychedelic experiences is difficult to describe because distinctions are the easy aspect of language, and wholeness the difficult. True ugliness and true beauty walk hand in hand in that strange place. It does one well to let go of the distinction between good and bad when one is on a trip. Forcing it won't help though. "Have you ever tried to relax? It is a paradox!"
I read Laozi for the first time at the end of a "bad" trip. It was a joy. To this day, it is the only text that makes perfect sense to me in the waking world and that other world, the world of dreams. That was my last trip. I wonder how the next one will be, when the time, place, and person are right for it?