Can a belief be justified if it can't be proved?

In light of a conversation I've been having with Safiyyah on logic and beliefs, I wanted to say a couple of things about faith, which I'll do in the next couple of blogs. In this blog, I want to say something about the rationality of believing things that can't be proved. In the next blog, I want to say something about the Christian idea of faith.

Most of the things we believe, we have some reason for why we think they are true. We believe one thing is true as a consequence of some other thing we think is true. It can't be the case, though, that everything we hold to be true has some justifying reason.

J.P. Moreland points this out in Skepticism & Epistemology when he discusses the itterative skeptic. An iterative skeptic is somebody who says, "How do you know that?" after everything you say. The assumption underlying the iterative skeptic's question is that you don't know something unless you can account for how you know it. (How does the iterative skeptic know that?) But if you have to give a reason for everything you know before you can be justified in your belief, then none of our beliefs are justified, because the only way we could justify them is to go through an infinite regress of reasons for how we know. We have to answer the iterative skeptic's question infinitely, and infinity cannot be completed because it is, by definition, without an end.

If we know anything at all, then, there must be some things we know that we don't need to give a justification for. There must be some starting point, some basic set of truths that are sort of built in, that we didn't derive from reasons.

I can name a few things I know but that I can't prove. I know that I exist, I know I'm thinking right now, I know how I feel, I know that 2+2=4, I know that if two things contradict they can't both be true, I know there are other minds, that the external world exists, and that the future will resemble the past. I can't prove any of these, but I don't see that I need to prove them before I'm justified in believing them.

The interesting thing to me is that the set of things we can't prove also happen to be the things we can know with the highest degree of certainty. Although I think it's possible I could be wrong about the existence of morality, the external world, the past, other minds, and the uniformity of nature, I do not think it's possible for me to be wrong about my existence, the content of my thoughts, peceptions, memories, the laws of logic, and basic math and geometry.

Consequently, and sort of in response to Safiyyah, I do not think that beliefs that were not arrived at by the use of logic are necessarily relegated to "blind faith." After all, logic cannot be derived from logic without the use of a viciously circular line of reasoning. Logic must be known a priori. Logic itself cannot be proved, but must be assumed before you can prove anything else. That doesn't mean our belief in logic is "blind faith." We are quite justified to believe in logic, because logic is rationally grasped. It's intuitively obvious.