Earlier quoted context omitted.
There's no truth claims. The point is that under the influence of psychedelics, you realize you can't know the truth. I understand you're looking at it from a scientific point of view, but the discussion is not scientific. Consciousness is probably the hardest body of knowledge to integrate with science. Nobody knows where consciousness comes from. Nobody knows how to measure it. I can tell you: "I'm conscious and aw…
>I can tell you: "I'm conscious and aware", but there's no way I can prove to you I'm not a philosophical zombie(someone that acts like it's conscious, but isn't). You can't prove that to yourself either, because a zombie has the same thoughts as you. You can't differentiate even subjectively whether you're a zombie or not.
I think the phrase "I think, therefore I am" is the essence here. A philosophical zombie does not "think". It looks like they do, but it's just a deterministic result of neurochemichal events going on in a brain that lives in the dark. Something like a neural network for instance. They can exhibit thought-like behavior without experiencing anything(as far as we know).