Plantinga’s Nutty Evolutionary Argument Against Naturalism

Where is Jesus?What better way to respond to atheists but to turn one of their own tools against them?  That’s the approach philosopher Alvin Plantinga tries to use with his Evolutionary Argument Against Naturalism (EAAN).  It’s not a new idea, and both C.S. Lewis and Charles Darwin anticipated it.  In brief, the question is: how can a human mind that’s the result of the clumsy process of evolution be trusted?

About “Darwin’s doubt,” Plantinga argues that only Christians can have confidence that their interpretation of the world is correct.  Naturalists can’t prove that minds are reliable until they’ve proven that the source of this claim (the mind!) is worth listening to.

Here’s where Plantinga claims to have turned the tables:

The high priests of evolutionary naturalism loudly proclaim that Christian and even theistic belief is bankrupt and foolish.  The fact, however, is that the shoe is on the other foot.  It is evolutionary naturalism, not Christian belief, that can’t rationally be accepted.

He says that if evolution is true, human beliefs have been selected for survival value, not truth, so why trust them?  And yet our beliefs are reliable, suggesting to Plantinga that something besides evolution created them.

Before we get into the specifics of Plantinga’s argument, let’s first establish a baseline.  Plantinga and naturalists agree that humans’ needs and desires are pretty logically matched:

Plantinga normal world

This is straightforward.  You go toward cuddly things, you run from scary things, you get to clean air if you can’t breathe, and so on.  This is the world we all know and understand.  But Plantinga imagines the naturalist’s world in which these links are jumbled.  He imagines a hominid Paul who has some problematic beliefs about predators:

Perhaps [Paul] thinks the tiger is a large, friendly, cuddly pussycat and wants to pet it; but he also believes that the best way to pet it is to run away from it.

So Paul’s instincts toward tigers keep him alive, but only by luck.  But unreasonable beliefs don’t stop with tigers.  Plantinga imagines the naturalist’s view of the world with beliefs having no connection with reality.  That is, he imagines something like this:

Paul’s response to the tiger was just a roll of the dice, and he got lucky.  But Plantinga supposes that all of Paul’s beliefs are arbitrary, not just those about tigers.  Some actions in this chart are benign, but some are dangerous.  When Paul sees something scary, his reaction is to walk toward it.  When he’s drowning, he’ll try to sleep.  When he’s hungry, he’ll satisfy that need with fresh air, and so on.  With his basic desires paired with ineffective methods, this guy is clearly too dumb to live.

This is where natural selection comes in.  Natural selection is unforgiving, and actions that don’t lead to survival are discarded.  Evolution easily explains why Plantinga’s Paul could not exist.

An article at Skeptic.com neatly skewers Plantinga’s argument with a familiar example.

If a professional baseball player [incorrectly perceived reality,] that is, if his perception of the movement and location of a baseball was something other than what it actually is, then he would not be able to consistently hit ninety-five mile per hour fastballs.

As an aside, let me admit that I have a hard time maintaining respect for those at the leading edge of philosophy.  Do they do work that’s relevant and pushes the frontier of human knowledge?  I’d like to think so, but when this is the kind of argument they give, it’s hard to keep the faith.

My advice to philosophers: when you get the urge to play scientist, better lie down until the feeling goes away.

Photo credit: Wikimedia

Related links:

  • “EAAN—a sad footnote to an illustrious career,” Shamelessly Atheist blog, 8/22/09.
  • “Evolutionary Argument Against Naturalism,” Iron Chariots Wiki.
  • PZ Myers, “Alvin Plantinga Gives Philosophy a Bad Name,” Pharyngula blog, 5/29/09.
  • Michael Dahlen, “What’s So Great About Kant?  A Critique of Dinesh D’Souza’s Attack on Reason,” eSkeptic, 8/17/11.
  • Greg Kokul, “The Evolutionary Argument Against Naturalism,” Stand to Reason (video, 3:59), 8/15/11.
  • “Evolutionary Argument Against Naturalism,” Wikipedia.

Philosophical Grounding: A Parable

God's existence doesn't seem likely.  Why imagine that Jesus is real?Consider this parable:

A certain mathematician, in a philosophical mood one day, wonders what grounds his mathematics.  The math works, of course, but he wonders if he’s missing something foundational.

He consults a friend of his, a theologian.  The theologian knows almost nothing about mathematics, but he knows his Christianity.

The mathematician says, “Mathematics is like an inverted triangle with the most advanced math along the wide top edge.  The top layer is grounded on the math below it, which is grounded on what is below, and so on through the layers, down to arithmetic and logic at the point at the bottom.  And that’s where it stops.”

The theologian nods his head wisely.  “I see the problem—what does the bottom rest on?”

The mathematician was silent.

“In your view, it rests on nothing,” said the theologian.  “It just sits there in midair.  But the problem is easily resolved—mathematics and logic comes from God.  There’s your grounding.”

“Are you saying that I need to convert to Christianity to be a mathematician?”

“No, just realize that you are borrowing from the Christian worldview every time you make a computation or write an equation.”

Satisfied that this nagging problem has been resolved, the mathematician returns to his work and thinks no more of it. 

The End.

So, is the mathematician any better off?  Is he faster or more accurate or more creative?  Do his proofs work now where they hadn’t before?  In short, did he get anything of value from the whole episode?

I’ve heard this “grounding” or “atheists borrow from the Christian worldview” idea many times, but I’ve yet to discover what this missing thing is that is being borrowed.

“God did it” is simply a restatement of the problem.  “God did it” is precisely as useful as “logic and arithmetic are simply properties of our reality” or “that’s just the way it is” or even “I don’t know.”  A curious problem has been suppressed, not resolved.  In fact, the theologian himself has his answer resting in midair because he provides no reason to conclude that God exists.  His claim is no more believable than that of any other religion—that is, not at all.

The person who stops at “God did it” has stated an opinion only—an opinion with no evidence to back it up.  It doesn’t advance the cause of truth one bit.

Mathematics is tested, and it works.  Scratch your head about what grounds it if you want, but God is an unnecessary and unedifying addition to the mix.