If there really is a complete unified theory that governs everything, it presumably also determines your actions. But it does so in a way that is impossible to calculate for an organism that is as complicated as a human being. The reason we say that humans have free will is because we can't predict what they will do.
Stephen HawkingIf we ever do find a complete theory of the universe, it would be a great triumph of human reason but it wouldn't leave much for us to do. We need an intellectual challenge.
Stephen HawkingIn his eyes shone the reflection of the most beautiful planet in the Universe---a planet that is not too hot and not too cold; that has liquid water on the surface and where the gravity is just right for human beings and the atmosphere is perfect for them to breathe; where there are mountains and deserts and oceans and islands and forests and trees and birds and plants and animals and insects and people---lots and lots of people. Where there is life. Some of it, possibly, intelligent.
Stephen Hawking