Plantinga’s Ghost in the Machine

by Matt DeStefano on November 19, 2011

I’ve been working on a response to Plantinga’s Evolutionary Argument Against Naturalism, which has me reading the newest iteration of the argument in his book with Michael Tooley, Knowledge of God. In it, another argument against naturalism got my attention. A neural event will have NP properties (the physiological properties of the neural event), and content (the proposition itself: ‘There is a sabertooth tiger in the bushes’). Given a naturalism account of thought and conscious activity, it seems we have a neural event that is causally and logically sufficient for our propositional attitudes. So my NP properties are logically and casually sufficient for my belief that ‘My argyle socks look awesome.’ According to naturalism, we need not countenance an immterial self/soul that thinks those things, because our NP properties are sufficient.

Plantinga feels that it’s impossible to imagine/conceive of a way in which an “underlying reality” (that is, the NP properties/neural event itself) can account for thought. He notes possibly the most well-known appreciation of this problem with Leibniz:

“One is obliged to admit that perception and what depends upon it is inexplicable on mechanical principles, that is, by figures and motions. In imagining that there is a machine whose constructionwould enable it to think, to sense, and to have perception, one could conceive it enlarged while retaining the same proportions, so that one could enter into it, just like into a windmill. Supposing this, one should, when visiting within it, find only parts pushing one another, and never anything by which to explain a perception. Thus it is in the simple substance, and not in the composite or in the machine, that one must look for perception.” (SEP)

I’m rather nonplussed by the prospect of using our imagination or ability to conceive as a means of determining reality. When I was younger, I had no idea how microwaves worked, and I thought the lights inside must be incredibly hot to warm up my Hot Pocket so quickly. I was always baffled when I opened the microwave and found that the air wasn’t exceptionally warm and the lights weren’t even remotely hot. How did it cool down so quickly? Does my inability to conceive of how a microwave works have any bearing on the reality of the microwave working? Assuredly not.

Let’s examine Plantinga’s proposed solution. Pretend for a moment that Leibniz’ Mill is an insurmountable problem and it seems we need to countenance an immaterial self to properly capture the phenomena of thought. Peter van Inwagen points out the difficulties inherent with either account: why should it be any easier to explain thought via dualism (immaterial parts maneuvering to form thought) than it should for materialism (material parts maneuvering to form thought)?

Plantinga argues that they are different because typically an immaterial self, a soul, is simple. It does not consist of parts, therefore thought does not need to be explained by the workings of its parts. One might ask, how does it produce thought? It produces thought because it is a basic activity of selves to think. Just as an electron has a charge, immaterial selves have thought. Therefore, asking the question How does an immaterial self think? is just as nonsensical as asking How does an electron have a charge?

It is harder for me to imagine an immaterial thing that thinks basically than it is to imagine a combination of parts generating thought. It prompts a laundry list of questions: How is thought properly basic to an immaterial self? How can an immaterial thing think, and do we have good evidence for thinking that they do?  How can an immaterial self have parts or not have parts? Where does the immaterial self causally interact with the material self? The pineal gland?

It seems to me that this is just another ghost in the machine (a la Ryle), and does very little in moving forward sensical talk about the process of thought. The inability to imagine or conceive of a system producing thought has no bearing on whether it actually can.

  • http://RichGriese.NET/ RichGriese.NET

    Nobody should take Plantinga seriously, he is jut a calvinistic kook apologist.


    • Tom Larsen

      Plantinga’s a Calvinist? I’m pretty certain he’s a Molinist…

  • JSA

    EAAN always seemed weak to me, but I’m not a professional philosopher.

    My first reaction is that we have lots of empirical evidence that our belief-formation mechanisms are *not* obviously reliable, so that would confirm evolution.

    In fact, theist Thomas Crisp used an argument from our *lack* of reliability to undercut PoE. I may have interpreted him uncharitably, but it seems that he and Plantinga cannot both be correct about our reliability:

    Bill Vallicella recently posted on our lack of reliability in recondite problems as well:

    • Matt DeStefano

      I think we have ample evidence for our lack of reliability, and I actually favor Paul Churchland’s response to the argument. He agrees with Plantinga that we would expect to be unreliable, and instead argues that science serves as our reliable belief-forming mechanism that allows us to formulate the belief of evolutionary naturalism. If Plantinga wants to argue that EN is epistemologically self-defeating, he would have to argue that science is unreliable instead of merely our native cognitive systems.

      Thanks for the links, I always go back and forth between my opinion of Vallicella’s work. 

  • JSA

    Vallicella is quite a character.  I don’t agree with his politics or his taste in music, but it’s fun to watch him “play chess”.

    I believe that EAAN was supposed to be an argument against metaphysical naturalism, not an argument against evolution.  IIRC, Plantinga said that theism doesn’t have a problem with evolution being the mechanism by which a belief-forming apparatus is manifested.  

    Evolution is scientific fact, and science is a reliable belief-forming mechanism, but EAAN still presents a “God of the gaps” problem and a potential “fine-tuning” problem:

    A.  God of the gaps — Natural selection surely explains the proliferation of species on the planet, but how do we explain the emergence of self-awareness and third-order intentionality, which are necessary for religion and science?  Evolutionary biology doesn’t have a good explanation yet.  In fact, self-awareness is biologically very expensive and has no apparent benefit.  A zombie or a Chinese room with the same behavior as a human, but without the need to waste brain glucose on pointless introspection and recursive self-referencing, would be far more biologically efficient.  Therefore, God.  [[ I hate "God of the gaps" arguments, BTW, but there are prominent atheists who argue along these lines to arrive at dualism. ]]

    B.  Fine tuning — As soon as we have a good evolutionary biology explanation for the leap to science, we will have to ask how likely this scenario would occur under slightly different natural starting conditions.  IOW, is the emergence of third-order intentionality guaranteed under a wide range of initial starting conditions?  Or is it somehow “special”?  Of course, we have no idea at all right now what the odds are, since our science isn’t advanced enough.

    Just for fun, there are two mind-bending scenarios that fall out of points A and B.

    A) What if atheists like Searle are correct, and our third-order intentionality and science are hopeless inefficient in evolutionary biology terms?  However, instead of proving that dualism is true, this only proves that we are one gigantic evolutionary mistake/spandrel?  If metaphysical naturalism is true, the universe will eventually see a species that is massively more intelligent than we are, but who lack self-awareness and are much more efficient.  Then they will wipe humanity out.  (This is roughly the theme of “Blindsight” by Peter Watts)

    B) One obvious way to find out how “fine-tuned” our universe’s parameters are would be to run a bunch of simulations on slightly different universe configurations and see which ones generate sentient life that values truth and invents science (as opposed to life which thrives based on false beliefs).  The only way to run that simulation would be to create trillions and trillions of virtual lives across many different universe configurations.  What if our universe is just a simulation being run by an advanced alien civilization who are trying to figure out if their universe is fine-tuned?

    • Matt DeStefano

      Right, sorry, I didn’t mean to imply that EAAN was trying to disprove evolution, I’m working on a paper analyzing Churchland’s response and he uses the term “evolutionary naturalism as a substitute for Plantinga’s terms.
      I find (A) compelling and I think perhaps it’s a flaw with our understanding of human beings’ representation scheme rather than a problem with metaphysical naturalism. In “Knowledge of God”, Plantinga argues similar to what you’re reproducing here and uses it to conclude dualism. I don’t find this terribly compelling because the dualist story offers no real solution to this problem, because it has the same difficulty we encounter with Leibniz’ Mill IMO.
      Personally, I am attracted to Churchland’s proposal that we see representation as a map of similarity and difference features of our environment, and I think this might go a long way in explaining the evolutionary function of seemingly wasteful representation schemes. He has a book due out in January that I think will touch on this issue at least to some extent.
      Thanks for the interesting comments, JS. I appreciate good philosophy.

  • Mike Gage


    Plantinga does say some strange things, but I think we’re pretty much forced to take him seriously if for no other reason than others take him seriously. Personally, I find some of his arguments interesting and I think he’s skilled at metaphysics. The people who dislike him, though, probably also dislike metaphysics. Also, someone told me recently that he’s actually not a Calvinist, but is commonly falsely associated with it. I don’t know which is true.


    If Yudkowsky’s presentation from Skepticon IV is available online anywhere, he talks about something similar to saying a soul is simple. He puts it into the context of computer programming and describes simiplicity in terms of minimum message length. Then he opines that we might not find the soul so simple if we try to program a computer to perform what the soul does (compared to programming it to do what a brain or an eye does).

  • http://RichGriese.NET/ RichGriese.NET

    Dear Mike,

    Not in the history industry. Yes, in the religion industry they like speculation since they have virtually zero historical data regarding Jesus or early Christianity, so they will latch onto anything they can. But, bet you cannot find even 6-12 folks in the history industry (remember with degrees from history schools, not religion schools) that think anything Plantinga says has anything of value to add to the history of early Christianity, or the theory that there was a historical Jesus.

    I am not interested in the supernaturalism of Christianity, but am very interested in the study of the early history of the group. I am always happy to talk to others that are also interested in this topic. My interest specifically is up till perhaps a generation or two after Irenaeus. But I would say I am interested in anything from the Maccabean revolt up till about 384CE when Christianity became the official religion of the Roman empire.


  • Matt DeStefano

    @ Mike

    That’s a great analogy, and I think the modern intuition about parts working together runs contrary to the intuition pump that Leibniz and Plantinga are advocating here. I’d love to see Yudkowsky’s presentation, I’ll use my Google-fu and attempt to find it. 

    @ Rich

    As far as I know, Plantinga doesn’t pretend to be a historical scholar. It might be a bit unfair to call him a “kook apologist” based on his historical writings alone. 

  • http://RichGriese.NET/ RichGriese.NET

    Dear Matt,

    I made my original comment as someone that studies the history of Christianity. Craig does makes historical claims, like that the resurrection is one of the most attested reliable historical events. I agree with you that he is not a historian. But, since he does make historical claims, he does cause problems in the history field. I call him an apologist, because if you have watched any of his public performances which he likes to pretend are scholarly debates, at the end he does always ask the crowd to accept jesus as their personal saviour. He is a evangelical apologist. I call him a kook, because if he thinks that pure speculation in his field of philosophy can somehow demonstrate a historical event, that is pure kookism. Speculation does not demonstrate historical events, if craig things his philosophical speculation even bears on the historical hypothesis that a Jesus existed his is delusional.

    You, or anyone else, is interested in understanding whey Craig is irrelevant with regards to trying to demonstrate the hypothesis that a Jesus existed in history, might watch & to see some of the apologetical tricks that Craig uses explained.

    Cheers! RichGriese.NET/religion

  • Matt DeStefano

    Certainly, but Craig and Plantinga are different people! 

  • http://RichGriese.NET/ RichGriese.NET

    Dear Matt,

    LOL, thanks for pointing that out. I had been having a number of different email discussions. Including both Craig and Plantinga. I guess I switched in this thread from Plantinga to Craig. While they are both radical Calvinists, and are both not historians but speculative philosophy degreed people, they are in fact different people. But my original point still holds. For those of us in researching and studying the history of Christianity, Plantinga (having nothing to do with history, but being in the speculation field of philosophy has nothing to offer on the subject). I would have to say, that this would also apply to William Craig too.


    • Tom Larsen

      … And, like Plantinga, Craig isn’t a Calvinist either; he’s a Molinist. You don’t seem to be very familiar with his work at all.

  • Sachin Maini

    Matt, I think you’ve hit the nail on the head in your criticism of this argument. It seems to me completely absurd to discount an explanation based on the fact that it’s intuitively difficult to understand – your example of the microwave is a good way to portray that there are many complex mechanical systems which give rise to properties which pose difficulty for a human intelligence to grasp how they could emerge when considering individual parts of the system.

  • Blue DKnight

    Matt, so his causal exclusion argument supposed to apply to conscious experiences, or just propositional thoughts? Does he offer any interesting arguments about consciousness, or does he offer any interesting admissions that his arguments ultimately rely on the intuition that experiences aren’t brain states? (I am collecting such public admissions of intuition-use for a chapter right now).

  • Matt DeStefano

    Hey BDK, it seems to apply to the breadth of conscious experiences, although Plantinga doesn’t make it terribly clear, as he is mostly arguing against the materialist POV in Knowledge of God. The most public admission Plantinga makes in regard to experience =/= brain states would be his claim that it’s impossible for “an assemblage of neurons, a group of material objects firing away, has a content” (KOG 53). 

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