Atheism Is Irrational: Alvin Plantinga

Further to my report on the 2014 Mere Anglicanism Conference, I call your attention to a marvelous interview with Christian philosopher Alvin Plantinga that appeared on Sunday's "The Stone" blog of the New York Times. Philosopher Garry Gutting of Notre Dame University conducts the interview, which is entitled: "Is Atheism Irrational"?

Prof. Plantinga gets right to the point:

In the British newspaper The Independent, the scientist Richard Dawkins was recently asked the following question: “If you died and arrived at the gates of heaven, what would you say to God to justify your lifelong atheism?” His response: “I’d quote Bertrand Russell: ‘Not enough evidence, God! Not enough evidence!’” 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.

In the same way, the failure of the theistic arguments, if indeed they do fail, might conceivably be good grounds for agnosticism, but not for atheism. Atheism, like even-star-ism, would presumably be the sort of belief you can hold rationally only if you have strong arguments or evidence.

To be an atheist, then, is to be irrational -- and naturally, atheists do not like having that pointed out one bit. If one claims to go by the actual evidence, then at best one can claim to be an agnostic (which is the real point of Dawkins' quote, even if Dawkins himself does not realize it).

Those whom one calls the "New Atheists" today -- Richard Dawkins, Daniel Dennett, Sam Harris and (the late) Christopher Hitchens -- are more properly described as anti-theists: they are militantly against the belief that there is a God. They have no positive belief of their own to uphold. Some claim  that "the physical world/universe is all there is -- there is nothing else" (à la Carl Sagan) is a positive belief -- until one points out that what is really meant by that statement is that there is no physical God in the Universe -- a statement with which (after the Resurrection, at any rate) theists would agree!

But let us return to Plantinga's interview, for there is much more to note. Asked about the evidence for God, Plantinga makes the point for which he is famous:

I should make clear first that I don’t think arguments are needed for rational belief in God. In this regard belief in God is like belief in other minds, or belief in the past. Belief in God is grounded in experience, or in the sensus divinitatis, John Calvin’s term for an inborn inclination to form beliefs about God in a wide variety of circumstances.

In a series of books toward the end of the last century, Prof. Plantinga restored theistic philosophy to a respected academic discipline. His trilogy on Warranted Belief is probably the capstone of his achievement. Essentially, he showed that there are key beliefs which we all hold, but which cannot be shown to be true by any hard evidence: for example, the belief that solipsism (the idea that I am the only thing that exists, and that everyone -- and everything -- else are just the products of my imagination) is false, and that other minds do indeed exist in the world.

No one can give any evidence for the existence of other minds, yet belief in other minds is what enables us to function every day: it is warranted belief. Such a belief is opposed to what some call "blind faith" -- belief in something despite the evidence against it. But warranted belief is not evidentiary belief -- it is a different but equally valid kind of knowledge upon which we act every day, without thinking about the evidence for or against it.

Likewise, for Christians, belief in God is warranted if (for example) the Resurrection really happened. Not only that, but as humans made in God's own image (i.e., with the faculties of reason, language and the ability to build on past achievements and acquired knowledge), Christians respond to the sensus divinitatis in them, the "sense of the divine" that enables them to appreciate and know that God exists. The New Atheists spend all their energy fighting against that sense, and maintaining that man does it all by himself, thank you!

In the key part of the interview, Plantinga responds to the criticism (as many atheists and agnostics suppose it to be) that "the world is not perfect":

Since the world isn’t perfect, why would we need a perfect being to explain the world or any feature of it?

A.P.: I suppose your thinking is that it is suffering and sin that make this world less than perfect. But then your question makes sense only if the best possible worlds contain no sin or suffering. And is that true? 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.

Think about it: The first being of the universe, perfect in goodness, power and knowledge, creates free creatures. These free creatures turn their backs on him, rebel against him and get involved in sin and evil. Rather than treat them as some ancient potentate might — e.g., having them boiled in oil — God responds by sending his son into the world to suffer and die so that human beings might once more be in a right relationship to God. God himself undergoes the enormous suffering involved in seeing his son mocked, ridiculed, beaten and crucified. And all this for the sake of these sinful creatures.

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.

Next, he slaps down the "God of the gaps" argument:

Some atheists seem to think that a sufficient reason for atheism is the fact (as they say) that we no longer need God to explain natural phenomena — lightning and thunder for example. We now have science.

As a justification of atheism, this is pretty lame. 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. A-moonism on this ground would be sensible only if the sole ground for belief in the existence of the moon was its explanatory power with respect to lunacy. (And even so, the justified attitude would be agnosticism with respect to the moon, not a-moonism.) The same thing goes with belief in God: Atheism on this sort of basis would be justified only if the explanatory power of theism were the only reason for belief in God. And even then, agnosticism would be the justified attitude, not atheism.

And in the final part of the interview, Plantinga summarizes the argument that he lays out in his latest book, Where the Conflict Really Lies: that materialism (the belief that the material world is all there is, as in the Carl Sagan quote above) does indeed imply atheism, but that it is logically inconsistent with the accompanying belief in evolution -- that everything somehow evolved, over eons of time, from the random interactions of inanimate fundamental particles.

Why? Read the rest of the interview for the full, and fascinating, discussion (or better yet, get his book and read chapter 10). Here is just a brief taste:

First, if materialism is true, human beings, naturally enough, are material objects. Now what, from this point of view, would a belief be? My belief that Marcel Proust is more subtle than 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 beliefs, he argues, are more than just material structures, because they have content to them, and because they lead to actions. (My thirst, for example, coupled with my belief that there is beer in the fridge, leads to my getting up and going to the fridge to get a beer.) And how does one represent content materially? Even if my belief about the beer in the refrigerator were false, it would still lead me to get up and go to get one, because of my belief -- regardless of whether it was true or false. Thus, the material structure of a belief is the same, whether a belief is in fact true or false.

But if evolution is true, then our beliefs have evolved over time. And evolution cares only about beliefs that promote our survival, i.e., beliefs that enable us to adapt to our environment. It does not ask that the beliefs be true, and does not even care if the beliefs are false. (Belief in phlogiston kept a lot of scientists fed and happy for quite some time.)

Any given belief of ours has a probability of being true, say, of 50-50. But it does not matter if we say that the probability is even greater, such as two-thirds, or 0.67. Because each of us holds, individually, thousands of beliefs. And the probability that materialistic evolution has led us to a collection of true beliefs over time is simply the product of their individual probabilities of being true: 0.67 x 0.67 x 0.67 x .... = 2/3 x 2/3 x 2/3 x .... = (2ⁿ/3ⁿ), where n equals the number of individual beliefs.

Would you like to know the value of the expression 2¹⁰⁰⁰/3¹⁰⁰⁰? All you have to do is plug it in at Wolfram Alpha: the answer is 8.1 x 10^-177 -- that is, 0.00000...81 where the dots stand for another 172 zeros. And that's just for one thousand beliefs! (Moreover -- to answer one of the objections to Plantinga's argument -- the number is still low even if we assume that most of the beliefs held by an individual are not independent, but interdependent. Indeed, their interdependency would make the entire rickety structure more fragile, and more dependent on more of them being true than false.)

Plantinga concludes:

So if you accept both materialism and evolution, you have good reason to believe that your belief-producing faculties are not reliable.

But to believe that is to fall into a total skepticism, which leaves you with no reason to accept any of your beliefs (including your beliefs in materialism and evolution!). The only sensible course is to give up the claim leading to this conclusion: that both materialism and evolution are true. Maybe you can hold one or the other, but not both.

So if you’re an atheist simply because you accept materialism, maintaining your atheism means you have to give up your belief that evolution is true. Another way to put it: The belief that both materialism and evolution are true is self-refuting. It shoots itself in the foot. Therefore it can’t rationally be held.

That logical conclusion, however, is sadly not the end of the story. For the interview garnered some 980 comments (before they were closed). Reading them is an education in why Plantinga's point is true: just because we are evolved does not mean that we are rational. Most of them are from atheists who deny that they hold any belief -- they insist that they just refuse to believe there is a God, and that the burden is therefore on those who claim that He exists. But that just begs the question of what they do believe -- e.g., in evolution, in materialism, and so on -- beliefs which are just as irrational as the belief they claim to be rational in rejecting.

I will let a metaphysical G. K. Chesterton have the last word (because he never really said it):

A man who won't believe in God will believe in anything.