By David Kyle. David Kyle Johnson, Ph.D., is an associate professor of philosophy at King’s College in Pennsylvania.
None of these philosophers, however, specialized in studying religious belief. On the other hand, there are numerous philosophers of religion who argue directly and philosophically for atheism and whose motivation Plantinga seems to completely ignore (e.g., A. C. Grayling; William Rowe; John Leslie Mackie, who argued that theism is irrational; and Michael Martin, who has written an entire philosophical defense of atheism). I know my own atheism has nothing to do with worries about autonomy or being watched or judged. It’s simply because I am not keen on taking things on faith—i.e., believing without sufficient evidence or pretending to know what I don’t) or committing logical fallacies. And it seems that to believe in God based on anything besides faith simply involves motivated reasoning that tries to justify theistic belief—reasoning that is rife with logically fallacious arguments.
As a logician, what I found interesting about Gutting’s interview is that, although unwittingly, it helps make this point. And since Gutting’s article will no doubt start making the rounds on Facebook (a New York Times article that argues against atheism!), I thought it was an appropriate topic for this blog. So I set out to highlight the logical mistakes that Plantinga makes in this interview. But once I was done writing, I had written almost 8000 words. (It takes much longer to point out what is wrong with a bad argument than to make a bad argument.) So I have divided it up my response and will post my reply in separate segments.
But to be clear, although I’m an atheist, it is not my goal here to prove that theism is irrational. My goal is to show that, contrary to article’s implied conclusion, atheism is not irrational, and to point out the logically fallacies employed by the argument that says so.
Gutting, like Plantinga, is a Notre Dame professor and essentially spends the article setting Plantinga up with a series of carefully worded questions that enabled Plantinga to very quickly summarize a number of pro-theistic arguments he is famous for. Although I will be quoting these summaries, I will do my best not to strawman Plantinga’s arguments (make them weaker than they are in the literature). I know the literature very well myself and I believe that every criticism I make applies equally to the more developed arguments he makes in the literature.
The first question Plantinga addresses is:
Should philosophers be agnostic?
Gutting suggests that perhaps philosophers are atheists because they think the arguments for God fail, but Plantinga argues that the failure of all arguments for God’s existence would merely justify agnosticism (remaining neutral about God’s existence), not atheism (believing that God does not exist). Believing God doesn’t exist would require a sound argument in its favor, Plantinga suggests. If we were considering whether or not there are an even or odd number of stars, we would need some kind of conclusive evidence in favor of one answer to embrace one over the other. Without any evidence either way, we should simply say “I don’t know.” The same holds if the evidence for God’s existence is inconclusive either way.
What logical fallacy is committed here? Shifting the burden of proof. Plantinga’s argument ignores a basic notion, well known among logicians, regarding where the burden of proof lies in existential debates—debates regarding the existence of something. Simply put, if you are the one who is suggesting that something exists, it is your job to provide the evidence that it does. Your belief that the thing in question does exist is not justified simply because no one else can prove it doesn’t. If you think Bigfoot exists, you have to provide the evidence that he does, and until you do I am justified in believing that he doesn’t. Of course, if we are talking about a non-existential hypothesis – like whether the number of stars is even or odd – that is a different matter. But if you are hypothesizing the existence of an entity, a lack of evidence for that entity justifies nonbelief in the entity. (To think otherwise commits the fallacy of appealing to ignorance, taking a lack of proof that something is false as evidence that it is true.) Where the burden of proof lies in existential debates is well established in logic and is usually only challenged (usually by non-logicians) when someone wants to believe in something but finally has to admit they have no evidence for it.
Bertrand Russell made this point famously with his celestial teapot example. Someone might suggest the existence of a teapot orbiting the Sun between Earth and Mars that, because it is so tiny that no one could ever see it, no one could ever prove doesn’t exist. Yet belief in such a teapot, clearly, would never be justified.
Plantinga actually addresses Russell’s example, suggesting that it’s not the case that we’re “ateapotist” because we lack evidence, but because “we have a great deal of evidence against teapotism.” The only way such a teapot could exist is if a nation with rockets put it there, yet there is good evidence that this has not occurred. Plantinga thinks that if the evidence really was a wash, being agnostic about the teapot would be the rational response.
But Plantinga is completely misunderstanding Russell’s argument. Russell was writing in 1952, five years before Sputnik and humans ever put anything into orbit. Russell wasn’t concerned about whether or not there was some way the teapot could have gotten into space, and whether such a thing happened. And he didn’t think that the fact that humans did not yet have the ability to launch something into orbit was the reason we were not justified in believing in such a teapot. He was simply concerned with the rationality of a belief that such a teapot existed, regardless of whether one thought it was placed there by us, by aliens, or whether it was just there inexplicably. The fact is, since the evidence is a wash, the rational default is to not believe.
What’s more, Russell is not even arguing for where the burden of proof lies in existential debates. That it lies on the side of the one making the novel claim—that something exists—was already established. He is simply supplying an example of that already established rule of reason in action to show that it is intuitive.
To make the point clear, consider a similar example of my own invention: the belief that there is a tiny diamond (too small to be detected) orbiting the Sun between Earth and Mars. There actually is a possible explanation for this being true: the asteroid that collided with the Earth and killed the dinosaurs (or any other large asteroid for that matter) could have ejected one into space in such a way that it began to orbit the sun as stated. We have no evidence that this did happen but of course have no evidence that it didn’t happen either. Should I thus be agnostic about the existence of such a diamond? Of course not. Clearly the rational default position is “a-diamondism.”
Interestingly, Plantinga’s response to Russell is strikingly similar to that of another Notre Dame professor, Peter van Inwagen. I saw van Inwagen deliver his response to Russell to the Society of Christian Philosophers in 2011 (it has since been published). Professor van Inwagen argued that, since the existence of such a teapot would need an explanation, yet it has none, ateapotism is justified. However, God’s existence does not need an explanation because God is, by definition, unexplained (or explains himself). So the fact that “ateapotism” is justified in the absence of evidence doesn’t mean that atheism is justified in the absence of evidence. The fact that God existence lacks an explanation can’t be evidence against it since it can’t have one.
The reply to van Inwagen, however, is two fold: First, theists have defined God in this way to get out of the responsibility of providing an explanation for him, but saying that he doesn’t need an explanation doesn’t mean that he doesn’t need one. Many atheists contend that if the singularity from which the big bang exploded—which, literally, is the simplest thing possible, given that it exists for no time, is as small as anything can be, and is governed by no laws—needs an explanation (as theists suggest), then certainly God, who is infinite in all respects, knows everything, can do everything, and is about as complicated as anything can be, would need an explanation too.
Of course, theists will likely reply that they are not just saying God doesn’t need an explanation, but that by definition he doesn’t because by definition he is the greatest being, and the greatest being can’t have an explanation. (Anything that explains God would be greater.) It’s not clear to me that this is the case; but even so, the basic rule of logic that, in debates on existential matters, the burden of proof lies on the one making the positive existential claim is true regardless of whether the entity in question is unexplained or self-explained. For example, if someone suggested the existence of an alien race that created itself through time travel (by traveling back in time and seeding its own race), I would still demand they provided evidence for such beings before I believed. In addition, I could maintain that there is an infinite number of universes, each of which exists inexplicably—without cause or explanation. Yet to rationally believe that any other such universe exists, I would demand evidence.
All in all, atheists are not being irrational by justifying their atheism simply in a lack of evidence for God’s existence, any more than I am being irrational in justifying “a-bigfootism” in a lack of evidence for Bigfoot.
Copyright David Kyle Johnson, 2014