Mathematics ... is indispensable as an intellectual technique. In many subjects, to think at all is to think like a mathematician.

Space is almost infinite. As a matter of fact, we think it is infinite.

If one were to take the bible seriously one would go mad. But to take the bible seriously, one must be already mad.

My generation of the Sixties, with all our great ideals, destroyed liberalism, because of our excesses.

You can't survive by sucking the juice from a wet mitten.

‎Not having time for a person, not being able to sit in silence together with somebody, that's the same as rejecting them, as being scornful about them.

The contented have time to worry about trivialities; often to the extent that they never achieve anything worthwhile.

If you spend your whole life being careful not to break anything, you'll get terribly bored, you know...I can't think of anything more fun than being impulsive!

ISIS represents the worst threat to freedom since Communism!

Is it necessary for me to drink my own urine? No, but I do it anyway because it’s sterile and I like the taste.

The number one thing is creating this world ["Trolls" ] - what the world is going to look like, feel like and what technology will we need to use to get there.