Is Alvin Plantinga for real? Alas, it appears so

by Massimo Pigliucci

I keep hearing that Notre Dame philosopher and theologian Alvin Plantinga is a really smart guy, capable of powerfully subtle arguments about theism and Christianity. But every time I look, I am dismayed by what I see. If this is the best that theology can do, theology is in big trouble. (Well, to be fair, it has been at least since David Hume.)

Recently, Plantinga has been interviewed by another Notre Dame philosopher with theistic leanings, Gary Gutting, for the New York Time’s “Stone” blog. I often enjoy Gutting’s columns, for instance his argument for why the Pope should revisit the Catholic’s Church position on abortion. Then again, whenever Gutting veers close to theism I have no problem taking him to task either.

In this case, Gutting’s interview is reasonably well structured, and he did ask some serious questions of Plantinga. It is the latter’s performance that left me aghast. Here is why.

The first question was based on recent surveys that put the proportion of atheists among academic philosophers at around 62%, slightly above what it is for scientists (it varies from sub-discipline to sub-discipline, too). Plantinga concedes that this is problematic for theism, considering that philosophers are the ones who are most familiar with all the arguments for and against the theistic position. So what does he do? He quotes Richard Dawkins, quoting Bertrand Russell, who famously said that if he found himself in front of god after his death he would point out to him that there just wasn’t enough evidence.

And here comes Plantinga’s first non sequitur: “But lack of evidence, if indeed evidence is lacking, is no grounds for atheism. No one thinks there is good evidence for the proposition that there are an even number of stars; but also, no one thinks the right conclusion to draw is that there are an uneven number of stars. The right conclusion would instead be agnosticism.” Right, except for the not-so-minor detail that the priors for there to be an even or odd number of stars are nowhere near the priors for there to be or not to be a god. More on this in a second, when we come to teapots.

Following up on the above (puzzling, to say the least) response, Gutting pointed out that the analogy with “even-star-ism” is a bit odd, and that atheists would bring up instead Russell’s famous example of a teapot orbiting the sun. Should we be agnostic about that? No, says Plantinga, because we have very good reasons to reject the possibility based on what we know about teapots and what it takes to put one in orbit around the sun. Precisely! Analogously — and this was Russell’s point — we have very good reasons not to take seriously the concept of a supernatural being (see comment above about priors). To see why, let’s bring in my favorite analogy. My Facebook profile (reserved for friends and family, please follow me on Twitter…) includes the usual question about religion, to which my response is that I’m an a-theist in the same way in which I am an a-unicornist: this is not to say that I know for a fact that nowhere in the universe there are horse-like animals with a single horn on their head. Rather, it is to say that — given all I know about biology, as well as human cultural history (i.e., where the legend of unicorns came from) — I don’t think there is any reason to believe in unicorns. That most certainly doesn’t make me an agnostic about unicorns, a position that not even Plantinga would likely feel comfortable endorsing. (I am, however, for the record, agnostic about even-star-ism. So, there.)

Gutting then brings up the usual trump card of atheists: the problem of evil (which, to be precise, is actually a problem only for the Judeo-Christian-Muslim concept of god, and therefore not really an argument for atheism per se). Plantinga admits that the argument “does indeed have some strength” but responds that there are also “at least a couple of dozen good theistic arguments” so that on balance it is more rational to be a theist.

Gutting, however, had to do quite a bit more prodding to get at least one example sampled from the alleged couple dozen on offer. First off, Plantinga states very clearly that the best reason to believe in (his) god is not a rational argument at all, but the infamous sensus divinitatis of Calvinistic memory, i.e. the idea that people experience god directly as a result of “an inborn inclination to form beliefs about God.”

This is so weak that it is hardly worth rebutting, but let’s elucidate the obvious for Prof. Plantinga anyway. To begin with, it is not clear even what counts as a sensus divinitatis in the first place. Does it equate to simply believing in god? If so, the “evidence” is circular. Or does it mean that some people have had some kind of direct and tangible experience of the divine, like witnessing a miracle? In that case, I’m pretty sure the number of such experiences is far less than Plantinga would like, and at any rate plenty of people claim to have seen UFOs or having had out-of-body experiences. Neither of which is a good reason to believe in UFOs or astral projection. Lastly, we begin to have perfectly good naturalistic explanations of the sensus divinitatis, broadly construed as the projection of agency where it doesn’t belong. The latter truly seems to me a near-universal characteristic of human beings, but it is the result of a cognitive misfire, as when we immediately think that someone must have made that noise whose origin currently escapes us (ghosts? a lurking predator?). It is sensible to think that this compulsive tendency to project agency was adaptive during human history, probably saving a lot of our ancestors’ lives. Better to mistake the noise made by the wind for a predator and take cover than to dismiss the possibility out of too much skepticism and end up as the dinner entree of said predator.

So Gutting pushed a bit more: could Plantinga please give us an example of at least one good theistic argument among those several dozens he seems to think exist? Well, all right, says the esteemed theologian, how about fine tuning? That does move the discussion a bit, as the fine tuning problem is a genuine scientific issue, which has by no means been resolved by modern physics (see recent Rationally Speaking entries on related topics).

Of course invoking fine tuning in support of theism is simply a variant of the old god-of-the-gaps argument, one that is increasingly weak in the face of continuous scientific progress, an obvious observation that Gutting was smart enough to make. Besides, even if it should turn out that fine tuning is best seen as evidence of intelligent design, there are alternatives on offer, some of which are particularly problematic for Christian theists.

Plantinga does concede that god-of-the-gap arguments are a bit weak, but insists: “We no longer need the moon to explain or account for lunacy; it hardly follows that belief in the nonexistence of the moon (a-moonism?) is justified.” Wow. I think I’m going to leave this one as an exercise to the reader (hint: consider the obvious disanalogy between the moon — which everyone can plainly see — and god, which…).

Eventually, Plantinga veers back toward the (alleged, in his mind) problem of evil, and takes it head on in what I consider a philosophically suicidal fashion: “Maybe the best worlds contain free creatures some of whom sometimes do what is wrong. Indeed, maybe the best worlds contain a scenario very like the Christian story. … [insert brief recap of “the Christian story”] … I’d say a world in which this story is true would be a truly magnificent possible world. It would be so good that no world could be appreciably better. But then the best worlds contain sin and suffering.”

Seriously? The argument boils down to the fact that Plantinga, as a Christian, finds the Christian story “magnificent,” that is, aesthetically pleasing, and that’s enough to establish that this is the best of all possible worlds. Maybe it’s just me, but I don’t find a world with so much natural and human imposed suffering “magnificent” at all, and it seems to me that if an all-powerful, all-knowing, and all-good god were responsible for said world he ought to be resisted at all costs as being by far the greatest villain in the history of the universe. But that’s just me.

Moving on, Gutting at one point asks Plantinga why — if belief in atheism is so questionable on rational grounds — so many philosophers, i.e. people trained in the analysis of rational arguments, cling to atheism. Plantinga admits to not being a psychologist, but ventures to propose that perhaps atheists reject the idea of god because they value too much their privacy and autonomy: “God would know my every thought long before I thought it. … my actions and even my thoughts would be a constant subject of judgment and evaluation.” Well, I’m no psychologist either, but by the same token theists like Plantinga (and Gutting, let’s not forget) delude themselves into believing in god because they really like the idea of being judged every moment (especially about what they do in the non-privacy of their bedrooms) and much prefer to be puppets in the hands of a cosmic puppeteer. Okay, suit yourselves, boys, just don’t pretend that your psychological quirks amount to rational arguments.

And we then come to “materialism,” which Gutting thinks is a “primary motive” for being an atheist. Here things get (mildly) interesting, because Plantinga launches his well known attack against materialism, suggesting that evolution (of all notions!) is incompatible with materialism.

Come again, you say? Here’s is the “argument” (I’m using the term loosely, and very charitably). How is it possible, asks the eminent theologian, that we are material beings, and yet are capable of beliefs, which are clearly immaterial? To quote:

“My belief that Marcel Proust is more subtle that Louis L’Amour, for example? Presumably this belief would have to be a material structure in my brain, say a collection of neurons that sends electrical impulses to other such structures as well as to nerves and muscles, and receives electrical impulses from other structures. But in addition to such neurophysiological properties, this structure, if it is a belief, would also have to have a content: It would have, say, to be the belief that Proust is more subtle than L’Amour.”

This, of course, is an old chestnut in philosophy of mind, which would take us into much too long a detour (but in case you are interested, check this). There are, however, at least two very basic things to note here. First, a materialist would not say that a belief is a material structure in the brain, but rather that beliefs are instantiated by given material structures in the brain. This is no different from saying that numbers, for instance, are concepts that are thought of by human beings by means of their brains, they are not material structures in human brains. Second, as the analogy with numbers may have hinted at, a naturalist (as opposed to a materialist, which is a sub-set of naturalist positions) has no problem allowing for some kind of ontological status for non-material things, like beliefs, concepts, numbers and so on. Needless to say, this is not at all a concession to the supernaturalist, and it is a position commonly held by a number of philosophers.

Plantinga goes on with his philosophy of mind 101 lesson and states that the real problem is not with the existence of beliefs per se, but rather with the fact that beliefs cause actions. He brings up the standard example of having a belief that there is some beer in the fridge, which — together with the desire (another non-material thingy, instantiated in another part of the brain!) to quench one’s thirst — somehow triggers the action of getting up from the darn couch, walk to the fridge, and fetch the beer (presumably, to get right back to the couch). Again, the full quote so you don’t think I’m making things up:

“It’s by virtue of its material, neurophysiological properties that a belief causes the action. It’s in virtue of those electrical signals sent via efferent nerves to the relevant muscles, that the belief about the beer in the fridge causes me to go to the fridge. It is not by virtue of the content (there is a beer in the fridge) the belief has.”

But of course the content of the belief is also such in virtue of particular electrical signals in the brain. If those signals were different we would have a different belief, say that there is no beer in the fridge. Or is Plantinga suggesting that it is somehow the presence of god that gives content to our beliefs? And how, exactly, would that work anyway?

Whatever, you may say, didn’t I mention something about evolution above? Yes, I’m coming to that. Here is Plantinga again, after Gutting suggested that perhaps we get a reasonable correspondence between beliefs and action because natural selection eliminated people whose brains were wired so to persistently equip them with the wrong belief (i.e., believing that the beer is in the refrigerator, when it’s not because you already drank yourself into oblivion last night):

“Evolution will select for belief-producing processes that produce beliefs with adaptive neurophysiological properties, but not for belief-producing processes that produce true beliefs. Given materialism and evolution, any particular belief is as likely to be false as true.”

The first part of this is true enough, and consistent with the fact that we do, indeed, get a lot of our natural beliefs wrong. To pick just one example among many, most people, for most of human history, believed that they were living on a flat surface. It took the sophistication of science to show otherwise (so much for the “science is just commonsense writ large” sort of platitude). It is the last part of Plantinga’s statement that is bizarre: 50-50 chances that our beliefs are true or false, given materialism and evolution? Where the heck do those priors come from?

But it gets worse: “If a belief is as likely to be false as to be true, we’d have to say the probability that any particular belief is true is about 50 percent. Now suppose we had a total of 100 independent beliefs (of course, we have many more). Remember that the probability that all of a group of beliefs are true is the multiplication of all their individual probabilities. Even if we set a fairly low bar for reliability — say, that at least two-thirds (67 percent) of our beliefs are true — our overall reliability, given materialism and evolution, is exceedingly low: something like 0.0004. So if you accept both materialism and evolution, you have good reason to believe that your belief-producing faculties are not reliable.”

Again, wow. Just, wow. This is reminiscent of the type of silly “calculations” that creationists do to “demonstrate” that the likelihood of evolution producing a complex structure like the human eye is less than that of a tornado going through a junkyard and assembling a perfectly functional Boeing 747 (the original analogy is actually due to physicist Fred Hoyle, which doesn’t make it any better).

The chief thing that is wrong with Plantinga’s account is that our beliefs are far from being independent of each other. Indeed, human progress in terms of both scientific and otherwise (e.g., mathematical) knowledge depends crucially on the fact that we continuously build (and revise, when necessary) on previously held beliefs. In fact, there is an analogous reason why the tornado in the junkyard objection doesn’t work: natural selection too builds on previous results, so that calculating the probability of a number of independent mutations occurring by chance in the right order is a pointless exercise, and moreover one that betrays the “reasoner's utter incomprehension of the theory of evolution. Just like Plantinga apparently knows little about epistemology.

So, to recap, Plantinga’s best “arguments” are: we don’t have a scientific explanation for the apparent fine tuning of the universe (true, so?); we don’t have a philosophical account and/or a scientific explanation of the problem of “aboutness” in philosophy of mind (again, true, so?); some people claim to have a mysterious sensus divinitatis (oh boy). Therefore, not only god, but the Christian god in particular, exists. Equipped with that sort of reasoning, I’m afraid Plantinga would fail my introductory critical thinking class. But he is a great theologian.