I despise people who depend on these things [heroin and cocaine]. If you really want a mind-altering experience, look at a tree.

Misuse of reason might yet return the world to pre-technological night; plenty of religious zealots hunger for just such a result, and are happy to use the latest technology to effect it.

It doesn't have to be the Grand Canyon, it could be a city street, it could be the face of another human being - Everything is full of wonder.

Middle age has been defined as what happens when a person's broad mind and narrow waist change places.

And I say, the meaning of life is what you make it. There will be as many different meaningful lives as there are people to live them.

To believe something in the face of evidence and against reason - to believe something by faith - is ignoble, irresponsible and ignorant, and merits the opposite of respect.

I do not believe that there are any such things as gods and goddesses, for exactly the same reasons as I do not believe there are fairies, goblins or sprites, and these reasons should be obvious to anyone over the age of ten.