There is a chart which attempts to explain different forms of atheism and theism which has been floating around the internet for several years now. (See it here: http://1.bp.blogspot.com/_QdYoufb0UsQ/TAimA3truGI/AAAAAAAAAA4/pcR-muRgp8c/s1600/Agnostic+v+Gnostic+v+Atheist+v+Theist.png). I have two major issues with this chart.
The first is the believe/know distinction. For “agnostic theist”, the chart says: 1) believes a god exists, and 2) doesn’t claim to know this belief is true. Consider this: have you ever heard anyone say, “I believe X, but I don’t know whether X is true”? Knowledge is generally accepted to be (barring outliers such as Gettier cases) something like “justified true belief”. So, consider the case of someone who believes X, yet doesn’t know X is true. This person would have to be in a very confusing mental state wherein he simultaneously believes both “X” and ” my belief that ‘X’ may not be justified or true”. Unfortunately for the chart, such a blatant mental contradiction probably isn’t possible (although, some people may claim to believe both things). Simply put, when we believe something, we also have a meta-belief that we know it.
My second issues is with the concept of belief itself. Beliefs are intrinsically tied to propositions, in that propositions are the things we believe (or not). When a theist says “I believe in God”, what he means is “I believe that the proposition ‘God exists’ is true”. Note that nothing is said about how confident (in an epistemic sense) the theist is that the proposition is true. Whether the theist is 60, 80, or 99 percent confident makes no difference here – he believes regardless. Now here’s where it gets tricky.
When we examine the proposition “God exists”, we’re going to have a confidence level that that proposition is true. If we’re atheists, it’s going to be less than 50% (otherwise, we’d be theists!) But then we have to consider another proposition: ‘God does not exist’. How do we assess our confidence in that proposition? Since it’s the negation of the first one, we can simply invert our confidence levels – so, if our confidence in “God exists” is 20%, it’s reasonable to say that our confidence in “God does not exist” is 80%, since these propositions are mutually exclusive. But, hey, that means atheists believe that a proposition is true. Oh, snap.
Of course, there is a third option – one might have no idea either way, and assess the confidence levels at roughly 50/50. Of course, this leaves us with a quite different set of terminology than the one laid out in the chart; one which consists of only atheism, agnosticism, and theism.
As a final thought, I leave you with this. It’s become quite popular since the release of The God Delusion to claim that while one is not 100 percent certain that God does not exist, one is 99.9 percent certain. This strikes me as being dishonest with oneself. It looks like nothing more than a rhetorical move deployed to avoid examination of one’s own beliefs. While it is important to have “wiggle room” to change one’s mind, 99.9 percent is effectively 100 percent, and any evidence or argument persuasive enough to shake such a high level of confidence would have to be not just extraordinary, but unreasonably so, especially when the issue in question is something like the existence of God, for which the answer isn’t immediately and obviously apparent.