What Is Evidence?
I’ve served on a jury just once in my life. The case involved the rape of a child. The direct evidence consisted almost solely in the testimony of the victim. The defense introduced what I would call “defeaters”—reasons to doubt the veracity of the testimony. Being an epistemologist, I paid careful attention to how both attorneys built their cases. When the trial concluded, the judge sent us into a private room to deliberate, and the jury chose me as foreperson. I found the procedure quite simple. There were several charges, written in propositional form. Each juror was to indicate whether they believed or disbelieved (or stood undecided on the truth of) each charge. I read them one at a time, and each juror stated their position. No one doubted, no one disputed. We unanimously affirmed each charge as true. The swiftness of the process surprised me. The prosecution had presented a powerful case, and the defense was weak. The man was convicted.
This all sounds quite reasonable. Beliefs, especially about important things, should be carefully formed and supported by evidence. This includes beliefs about God or the absence of gods. But I think a great deal of confusion and clutter arises because we have misconceptions about what evidence is and how it supports beliefs. What kinds of things can support our beliefs? Probably just two things: experiences and other beliefs. For example, what supports my belief that the computer in front of me is black? Well, one thing that supports this belief is my visual experience of the computer. It appears black to me. That is my primary source of evidence. What supports my belief that this computer, if tossed into a lake, will sink? One thing that supports this belief is another belief: the belief that things of a certain density and configuration cannot float in water. Both my beliefs—about the color and buoyancy of the computer—seem perfectly rational given my evidence. My jury experience was similar. My belief that the suspect was guilty was supported by my experience of listening to testimony and other beliefs about the situation, like the reliability of that testimony.
So how does all this help us in thinking about the rationality of belief or disbelief in God? One person believes there is a God, and one person believes there are no gods. Both are belief-states. This has nothing to do with certainty or claims to “know.” Some may say that disbelief in gods is a “lack of belief.” But this isn’t quite accurate. If I lack a belief about some matter, it means I’ve never considered it at all. Five seconds before typing this sentence, I lacked a belief about whether pigs are descended from unicorns. I had never considered it. I didn’t affirm it, I didn’t deny it. I wasn’t even “undecided.” I just had no mental state about it whatsoever. Now I do—I deny it. Anyone who has thought about whether gods exist has a view about the matter, and any view you hold (even being undecided) requires support from reasons (evidence) to be considered rational.
The Rubber Meets the Road
So, if you are a God-believer, what is your evidence? If you are a god-denier, what is your evidence? You might appeal to some combination of experiences and beliefs that you have. But there are still at least two questions that come up, one for theists and one for atheists. (1) Is there really evidence for God? And (2) what should we believe if there is no evidence for God?
This may shock you, but I’ve never met a theist who has no evidence for their belief. It is almost impossible to form a genuine belief without evidence. For theists, this includes “religious experiences,” testimony, philosophical arguments, etc. However, not all evidence is created equally. So, if you are a skeptic about God, rather than tell the theist she has no evidence, inquire about the quality of that evidence. Still, even if a theist’s belief is only supported by misleading evidence, this does not make her irrational. Suppose a person unknowingly lives in the Matrix. That is, all her perceptions are being fed to her by a super-duper neuro-computer that can simulate anything. She now believes she is climbing the steps of the Eiffel Tower, but in reality, her body is sleeping in a plastic tube. Is she rational to believe that she is climbing the steps of the Eiffel Tower? Certainly. Her belief is supported only by misleading evidence, but she is being quite rational and epistemically responsible in taking it all at face-value. So, as I argued in the last post, rationality and truth can come apart. Similarly, even if there are no gods, theism can be quite rational (although rather tragic). The break-down in the analogy is that, unlike those trapped in the Matrix, we do have access to counter-evidence and friends who can help us identify bad beliefs.
So what about the second question? If you believe there are no gods, and your basis for this is the claim that there is no evidence for gods, is this a rational position? This will depend on your total evidence. It is true that you shouldn’t believe something without evidence for it, but it is also true, in the same way, that you shouldn’t disbelieve something without evidence against it (or evidence for disbelief). For example, if your position on extraterrestrial intelligence is that there is none, you should be able to give a reason for your position. If I asked you about it, and you said, I don’t know, that’s just my view,” I would consider that an irrational position. Would it be enough to say, “there’s no evidence of E.T.?” Well, it depends on whether we should expect evidence for E.T.. If I believe that there are no living dinosaurs in my bedroom, I don’t need much evidence for this view to be rational. It is the absence of evidence that matters here because it is indisputable that there would be evidence if there were a living dinosaur in my bedroom. My evidence is an inferential belief — if there were dinos here, there would be evidence; there’s not, so there are no dinos. But the key is that it must be more or less agreed on by all parties that evidence for the thing in question is expected. In E.T.’s case, I don’t think we should expect to see evidence, given the size of the universe.
So, if the atheist lacks evidence for God (perhaps they’ve never had a religious experience or credible testimony), and she possesses evidence for disbelief, then she may be rational in her disbelief. But now you must be prepared to face-off with the theist on even terms. You both make a claim, you both must offer a defense of your position. Alternatively, if you think there’s simply no evidence whatsoever (either way) regarding the question of whether gods exist, then the rational position is to be undecided (sometimes called being ‘agnostic’). This is the “default” position, for those who have considered the question.