An excerpt from the famous 1948 BBC Radio debate transcript on the existence of God, reprinted in Bertrand Russell's On God and Religion edited by Al Seckel (Prometheus Books) - full transcript available on Philip Porvaznik's personal website. On the linked page you can also listen (.mp3) to the edited portion of the debate on "Contingency".
A DEBATE ON THE EXISTENCE OF GOD
Bertrand Russell [hereafter R:] and F.C. Copleston [hereafter C:]
C: As we are going to discuss the existence of God, it might perhaps be as well to come to some provisional agreement as to what we understand by the term "God." I presume that we mean a supreme personal Being -- distinct from the world and Creator of the world. Would you agree -- provisionally at least -- to accept this statement as the meaning of the term "God"?
R: Yes, I accept this definition.
C: Well, my position is the affirmative position that such a Being actually exists, and that His existence can be proved philosophically. Perhaps you would tell me if your position is that of agnosticism or of atheism. I mean, would you say that the non-existence of God can be proved?
R: No, I should not say that: my position is agnostic.
C: Would you agree with me that the problem of God is a problem of great importance? For example, would you agree that if God does not exist, human beings and human history can have no other purpose than the purpose they choose to give themselves, which -- in practice -- is likely to mean the purpose which those impose who have the power to impose it?
R: Roughly speaking, yes, though I should have to place some limitation on your last clause.
C: Would you agree that if there is no God -- no absolute Being -- there can be no absolute values? I mean, would you agree that if there is no absolute good that the relativity of values results?
R: No, I think these questions are logically distinct. Take, for instance, G. E. Moore's Principia Ethica, where he maintains that there is a distinction of good and evil, that both of these are definite concepts. But he does not bring in the idea of God to support that contention.