Overpopulation is perhaps the biggest problem facing us, and immigration is part of that problem. It has to be addressed.

The more we pour the big machines, the fuel, the pesticides, the herbicides, the fertilizer and chemicals into farming, the more we knock out the mechanism that made it all work in the first place.

All technology should be assumed guilty until proven innocent

Truth and beauty can still win battles. We need more art, more passion, more wit in defense of the Earth.

Sometimes luck is with you, and sometimes not, but the important thing is to take the dare. Those who climb mountains or raft rivers understand this.

Understanding how DNA transmits all it knows about cancer, physics, dreaming and love will keep man searching for some time.

We are no longer inheriting the Earth from our parents, we are stealing it from our children.

Without wilderness, the world's a cage.

Apollo 13, as you may remember, gave us a reactor that is bubbling away right now somewhere in the Pacific. It's supposed to be bubbling away on the moon, but it's in the Pacific Ocean instead.

Bring diversity back to agriculture. That's what made it work in the first place.

Let the mountains talk, let the river run. Once more, and forever.

I have always suspected that correctness is the last refuge of those who have nothing to say.

You must have been warned against letting the golden hours slip by but some of them are golden only because we let them slip by.

It would do the world good if every man would compel himself occasionally to be absolutely alone. Most of the world s progress has come out of such loneliness.

I came to Freud for facts. I read 'The Interpretation of Dreams' and I thought- 'Oh, here is a man who is not just theorizing away, here is a man who has got facts.

I'm someone who admires artists like Madonna and David Bowie, who really change their sound drastically between each record.

I would still have old ladies come up to me after the show and pat me on the cheek after I had said all this vulgar stuff. They would be like, 'Oh you're a silly boy - we know you're just playing.

Supposing truth is a woman -- what then?

I went to engineering school, I went to physics class. I said, 'Screw this, I don't want to be here. I'd much rather be at a club playing music.

Over a half-century has passed since the hell of the Holocaust, but its spectre still hangs over the world and doesn't allow us to forget.

You little know what a ticklish thing it is to go to law. [Lat., Nescis tu quam meticulosa res sit ire ad judicem.]