God Delusion Debate 3/11: Dawkins vs Lennox

“Proof in the strict sense only comes in mathematics”, says Prof Lennox. Except, of course, mathematical logicians love to equivocate between:

(a) proof consists of deduction by a valid rule of inference from premises assumed to be true

(b) the above proposition, plus the premises are necessarily true

When one asks how (b) is know to be true, one is either told that the premises cannot be properly understood and yet not understood to be true; or that the premises can just be seen to be true; or one is offered yet another proof from other premises.

I do wish mathematicians would stop pretending that, if they pursue the concept of this special category of “logical” truth, they are somehow better than philosophers talking of necessary or analytic or a-priori truths.

Whereas, in fact, all claims to “truth” are open to disproof, including such fundamental rules of inference as non-contradiction, ie ┐[p AND ┐p], or the rule [p ├ ┐(┐(p)]. Including, of course, the sentence that I just wrote down – I mean the one beginning “Whereas, in fact….”

The thirst for logical truth is the final and purest expression of the transcendental religious impulse, which is why Prof Lucas is happiest in these two worlds of thought.

Regards and ♥, andrea