The test of a theory is its ability to cope with all the relevant phenomena, not its a priori 'reasonableness'. The latter would have proved a poor guide in the development of science, which often makes progress by its encounter with the totally unexpected and initially extremely puzzling.

Theologians have a great problem because they're seeking to speak about God. Since God is the ground of everything that is, there's a sense in which every human inquiry is grist to the theological mill. Obviously, no theologian can know everything.

Bottom up thinkers try to start from experience and move from experience to understanding. They don't start with certain general principles they think beforehand are likely to be true; they just hope to find out what reality is like.

I'm a very passionate believer in the unity of knowledge. There is one world of reality - one world of our experience that we're seeking to describe.

When you realize that the laws of nature must be incredibly finely tuned to produce the universe we see, that conspires to plant the idea that the universe did not just happen, but that there must be a purpose behind it.

I very much enjoyed my career in science. I didn't leave science because I was disillusioned, but felt I'd done my bit for it after about twenty-five years.

Evolution, of course, is not something that simply applies to life here on earth; it applies to the whole universe.