Question to Polkinghorne: Can we Prove that God does not Exist?

Gingerich: Here is a question for you, John. Could you imagine an ultimate argument that God is not existent? If we cannot refute this mode of explanation, then it is just a matter of belief. But how can we be sure or convinced that it is not just wishful thinking?

Polkinghorne: That’s a very interesting question. I think that certainty, in the sense of logical proof, is a pretty spare quantity. There isn’t too much of it around. I mean, Kurt Gödel has told us that even mathematics has its aporia, as the theologians say, its uncertainties. And I think it is also the case that there is a sort of complementary relationship between things that are really interesting and things that can be proved. So, I think we shouldn’t worry about proof and certainty.

That doesn’t mean that anything goes. We should search for motivated beliefs. But I think this is true of both science and religion and everything that lies between them, we will attain beliefs that are motivated but will never be certain. I think one of the best books on the philosophy of science written in the 20th century is Michael Polanyi’s book, Personal Knowledge. Polanyi was a distinguished physical chemist before he became a philosopher. That means he’s been not very well accepted in the philosophical community, I am afraid to say. He wrote this book, he said - and he was talking in relation to his scientific beliefs - how I can hold to what I believe to be true knowing that it might be false. And that is the human condition, I think, whether it is in science or religion or other things. So, I think we shouldn’t get fixated upon certainty. I don’t think you can prove God exists; I don’t think you can prove God does not exist.

Contributed by: Sir John Polkinghorne and Steven Weinberg