My advice to myself and to everyone else, particularly young people, is to turn on, tune in and drop out.

I think that marijuana makes you stupid but sensual. I've watched many of my friends and loved ones become more erotic and dumber - just going around with a glazed expression on their faces from their last orgasms to the next - and found them really quite boring.

I'd just like to see thinking come back in style. I haven't heard a new idea in eight years. Let's get ordinary people arguing and talking again. I want to trigger new circuits in their nervous systems. That's the philosopher's job and I am the most important philosopher at this time.

We are dealing with the best-educated generation in history. But they've got a brain dressed up with nowhere to go. Science is all metaphor. In the information age, you don't teach philosophy as they did after feudalism. You perform it. If Aristotle were alive today he'd have a talk show. If you don't like what you are doing, you can always pick up your needle and move to another groove. If you take the game of life seriously, if you take your nervous system seriously, if you take your sense organs seriously, if you take the energy process seriously, you must turn on, tune in, and drop out.

My favorite three words in the English language are: ’I don’t know’, because every time I say them, I learn something new.

To use your head, you have to go out of your mind.

There are three side effects of acid: enhanced long-term memory, decreased short-term memory, and I forget the third.