On a memorable hallucination while taking LSD
"I had been reading about the color indigo, how it had been introduced into the spectrum by [Isaac] Newton rather late, and it seemed no two people quite agreed as to what indigo was, and I thought I would like to have an experience of indigo. And I built up a sort of pharmacological launchpad with amphetamines and LSD, and a little cannabis on top of that, and when I was really stoned I said, 'I want to see indigo now.' And as if thrown by a paintbrush, a huge pear-shaped blob of the purest indigo appeared on the wall.
"Again it had this luminous, numinous quality; I leaped toward it in a sort of ecstasy. I thought, 'This is the color of heaven.' ... I thought maybe this is not a color which actually exists on the Earth, or maybe it used to exist or no longer exists. All this went through my mind in 4 or 5 seconds, and then the blob disappeared, giving me a strong sense of loss and heartbrokenness, and I was haunted a little bit when I came down, wondering whether indigo did exist in the real world.
"I would turn over little stones. I once went to a museum to look at azurite, a copper mineral which is maybe the nearest [to] indigo, but that was disappointing. I did in fact have that experience again, but when I had it the second time, it was not with a drug, it was with music — and I think music can take one to the heights in a way comparable with drugs."
On hallucinations that accompany bereavement
"With any hallucinations, if you can do functional brain imagery while they're going on, you will find that the parts of the brain usually involved in seeing or hearing — in perception — have become super active by themselves. And this is an autonomous activity; this does not happen with imagination. But hallucination, in a way, simulates perception, and the perceptual parts of the brain become active. ... There's obviously a very, very strong passionate feeling of love and loss with bereavement hallucinations, and I think intense emotion of any sort can produce a hallucination."
On the hallucinations accompanying his migraines
“ I usually get the zigzag, but I may also see lattice patterns, like tessellations; sometimes these lattice patterns seem to cover people's faces or a piece of paper I'm writing on. I mostly get complex geometrical patterns