Hello Professor Reppert,
I recently came across some posts involving the notions of necessity and possibility on William Vallicella's blog and it reminded me of a debate I had years ago with someone on the SecularWeb. I'm hoping that you can offer your impression of the topic.
As I'm sure you're aware, in Chapter 2 of his Atheism:a philosophical justification, Michael Martin argues that theological assertions are neither true nor false. He offers a modest defense of a variation of a verificationist style criterion of factual meaningfulness.
It has been claimed by some critics that Martin's overall position in Atheism is inconsistent. They claim that despite arguing that theological assertions are neither true nor false he does however proceed to offer arguments for the falsity of theism. Specifically, he argues that there is no good reasons to believe theism is true and that there are quite a few good reasons to believe theism is false. The critics seem to be saying that he cannot argue BOTH that theism is neither true nor false and then make arguments regarding its truth value.
Martin has defended himself here:
Martin claims that his critics are confused about the structure of his argument. He thinks his critics attribute to him the follow argument structure:
(a) p is neither true nor false.
(b) p is true.
However, he goes on to state that the actual structure of his argument is:
(a) p is neither true nor false.
(b) if p is either true or false, then p is true.
He goes on to summarize his argument ---"God exists" is probably factually meaningless. But if it's meaningful then it's false.
In my discussion on the SecularWeb, I argued that if Martin believes that theism is likely neither true nor false then he must believe that it is POSSIBLY true or false. My reasoning was that if you believe p is likely then you must believe its denial is possible. (It may be possible to deny that.) And if you believe something is possibly true or false then you must believe that it is possible that p is true.
If p is "God does not exist." and p is possibly true or false then "God does not exist" is possibly true. In other words, Martin must presuppose that theism is factually meaningful in order to even formulate his "fall back position" argument.
Anyway, I was hoping that you could make some comments or offer some suggestions about the issue. Is my reasoning completely bogus?
I appreciate your time. Any comments would be greatly appreciated.
I'd want to make sure we have a clear distinction between epistemic and metaphysical possibility. Martin thinks that theism is probably meaningless but holds out the epistemic possibility that it is meaningful (in which case he says it is certainly false). He might be saying something like this: According to every theory of meaning that I know and think likely to be true, theism comes out meaningless. But just in case those theories turn out not to be true, then I suppose it might be meaningful, but if it is it is almost surely false. So I don't know if he can be tagged with an incoherence here, on the face of things. However, I think the charge of meaninglessness against theism has been refuted time and again, and people should have realized the jig was up when ardent atheist J. L. Mackie, in The Mirace of Theism, maintained that Swinburne had effectively refuted the charge of meaninglessness.