Stephen Hawking

However bad life may seem, there is always something you can do, and succeed at.

It would not be much of a universe if it wasn`t home to the people you love.

Intelligence is the ability to adapt to change.

A belief that heaven or an afterlife awaits us is a "fairy story" for people afraid of death.

Quiet people have the loudest minds.

My goal is simple. It is complete understanding of the universe, why it is as it is and why it exists at all.

I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.

I think computer viruses should count as life. Maybe it says something about human nature, that the only form of life we have created so far is purely destructive. Talk about creating life in our own image.

We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.

It has certainly been true in the past that what we call intelligence and scientific discovery have conveyed a survival advantage. It is not so clear that this is still the case: our scientific discoveries may well destroy us all, and even if they don't, a complete unified theory may not make much difference to our chances of survival.

Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory.

The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?

Someone told me that each equation I included in the book would halve the sales.