"Universal causal determinism cannot be rationally affirmed. When you think about it – there is a sort of dizzying self-defeating character to determinism. For if you come to believe that determinism is true, then you have to believe that the reason you have come to believe it is simply because you were determined to do so. You haven’t been able, in fact, to sift through the arguments and the evidence and to freely weigh them and make up your mind on the basis of the argument and the evidence. It is just that you have been causally determined to believe in determinism.[1] So, the difference between the person who weighs the arguments for determinism and becomes a determinist and the person who weighs those arguments for determinism and rejects them is simply that the one was determined to believe in them and the other one was determined not to believe in them. So when you come to realize that your decision to believe in determinism was itself determined and even your present realization of that fact – you come to realize that your belief in determinism is itself determined – then there is a sort of vertigo that sets in. Everything you think – even the very thought that you are thinking about that – is itself determined. It is outside your control. You were just determined to believe in it. So while it would be the case that determinism could be true – maybe determinism is true – nevertheless it is very hard to see how it could ever be rationally affirmed. Determinism is literally self-defeating – it is rationally unaffirmable – because its very affirmation would undermine the rationality of that affirmation. In affirming determinism to be true, you are in effect affirming that that decision is not rationally made but simply determined to be true. So universal causal determinism, it seems to me, cannot be rationally affirmed."
Read more: http://www.reasonablefaith.org/defenders-2-podcast/transcript/s8-10#ixzz42Yg5JFTe