I stumbled upon this talk by Alvin Plantinga recently. In case you don’t know who Plantinga is: He’s an american philosopher and christian apologist, most famous for his version of the modal ontological argument and the evolutionary argument against naturalism, which he also presents in this lecture. And at certain times he’s so wrong it’s almost embarrassing. In fact, it makes me wonder why anyone would take Plantinga serious as a philosopher at all:
Obviously, I’m not a philosopher, but Plantinga argues specifically against naturalism (which I espouse) and I happen to currently read The Big Picture – On the Origins of Life, Meaning, and the Universe Itself by Sean Carroll. Carroll is one of the very few people whom I find myself agreeing with on almost every point – in this book, he defends his worldview of poetic naturalism using epistemological bayesianism, both of which I find incredibly attractive, so I thought I’d have some fun and give my two cents on Plantinga from those points of view.
The elevator pitch version and three talks on poetic naturalism can be found here – roughly put, it claims that everything that exists is ultimately described by physics alone:
“Naturalism is a philosophy according to which there is only one world — the natural world, which exhibits unbroken patterns (the laws of nature), and which we can learn about through hypothesis testing and observation. In particular, there is no supernatural world — no gods, no spirits, no transcendent meanings.”Sean Carroll here
However, in poetic naturalism we are justified in saying that other things “exist”, if that is a useful way to talk about the world on a higher level of abstraction. If I talk about e.g. some person, describing them on the basis of fundamental particles/fields/whatever simply isn’t appropriate. Talking about their intentions, free will, desires etc. on the other hand is – it allows us to form hypotheses about people, derive predictions – hence psychology, sociology, etc. So even though human behavior ultimately is the result of the laws of physics acting on purely physical entities, it is infinitely more useful to talk about them in terms of human characteristics, hence we’re perfectly justified in saying that e.g. we have free will – it’s just that whatever we mean by free will is the result of purely deterministic natural laws.
By Bayesianism I mean the notion, that the degree to which we believe and place confidence in some proposition should be the probability of that proposition being true given the available information. This is a significant point, because even if we (in most practical cases) can’t assign definite values to those probabilities, the sheer fact that they are probabilities means they are governed by the mathematical laws of probability theory. In particular, this tells us a lot about how they are influenced by new information – i.e. how we should update our beliefs and the confidence we put in them, based on (new or preexisting) evidence.
The thesis Plantinga presents and defends in his talk is the following:
“I just wanna talk about evolutionary theory here. Contemporary evolutionary theory. […] I want to comment on the question whether or not that’s compatible with theistic belief. Belief in God. […] Contemporary evolutionary theory is not incompatible with theistic belief, belief in God. And I want to argue that the main anti-theistic arguments involving evolution, together with other premises, also fail. Then I want to argue thirdly, […] that there is, then, a science and religion, or science quasi-religion conflict, but it’s between naturalism and science, and not between theistic religion, Christianity, let’s say, and science.”Alvin Plantinga (06:20)
…and we’re already off to a weird start. Naturalism (pretty much by definition) accepts every result that the scientific method has lead to and is inherently based on accepting the scientific method as a reliable methodology to discover truths about the world. Conversely, the scientific method entails pragmatic naturalism (i.e. science excludes – not in principle, but pragmatically – anything that is not subject to empirical observation, i.e. anything outside of the natural world). If you look into any scientific paper, whether about physics, chemistry, biology or psychology, you won’t find any reference to non-naturalistic forces or beings.
It didn’t have to be that way – Newton invoked god regularly in his scientific writing. It just so happens, that over time, naturalism has won in science, at the very least pragmatically. It would be seriously problematic, if one of the universal, principal, pragmatic assumptions used in science is incompatible with it, but okay, let’s just see where he’s going with that (Spoiler: his evolutionary argument against naturalism of course).
But the other problem is that merely showing that theism and science/evolution are compatible is completely pointless (and that’s what he’s going to do). Everything observable can be ad-hock rationalized to be compatible with theistic beliefs – I can always take one step back and proclaim “yes, god made it look like that on purpose”, and it is with that kind of reasoning, that Plantinga dismisses perfectly valid arguments against (the plausibility of) theism, as we will see later on. But this doesn’t get us anywhere: mere compatibility implies nothing, it allows for no testable predictions and it doesn’t mean that theism is even remotely plausible. Nothing as vaguely defined as theistic belief can ever be excluded with metaphysical certainty. Neither can the existence of unicorns, Russell’s teapot orbiting earth, the flying spaghetti monster. So just showing that science and theism are not perfectly contradictory is an exercise in futility – it’s trivially true.
Here’s how Plantinga talks about “evolutionary theory”:
“Evolution covers a multitude of theses: […]
- First of all, the ancient Earth thesis, that the Earth is maybe four billion years old. Who knows exactly how old. […] The universe itself is, maybe 13 billion years old. […]
- Second, the thesis of descent with modification,where the idea is that all the vast variety of flora and fauna […] all came to be by virtue of offspring differing, ordinarily in rather small respects, from their parents. And these differences proliferate and spread out, and as a result you get this enormous variation. […]
- And then third, there’s the common ancestry thesis. The idea that if you pick […] any two living creatures […] and trace their ancestry far enough back, you’ll run into a common ancestor. […]
- And then the fourth one, Darwinism, in some ways, the most important one. […] The claim that the principal mechanism driving this process of descent with modification is natural selection winnowing or working on random genetic mutation. […] These random mutations occur periodically. Some of the, most of them are lethal, but some, some are in fact, not merely, not lethal, but adaptive.”
Alvin Plantinga (08:50)
Now, I’ll happily grant Plantinga his terms if he wants to call all of those “evolution”, but it’s worth pointing out, that
- the age of the earth (let alone the universe) is not part of evolutionary theory, even if it is corroborated and entailed by what we know about evolution,
- descent with modification itself is not a thesis but an observable fact – only the claim that all of the biological variation is due to descent with modification is part of the theory,
- Natural Selection is not the only driver of evolutionary changes (Wikipedia lists e.g. Natural selection, Biased mutation, Genetic drift, Genetic hitchhiking and Gene flow),
- most mutations are not lethal but for all practical purposes neutral, and mutations are not the only source of variations in the gene pool (again – Wikipedia lists e.g. Mutation, Sex and recombination (not surprisingly), and Gene flow)
- What Plantinga calls “Darwinism” is either horribly outdated (if we take it exactly as he describes it) and thus irrelevant, or – augmented by the other mechanisms driving evolution – better called the modern evolutionary synthesis, which Wikipedia describes as “a 20th-century synthesis of ideas from several fields of biology that provides an account of evolution which is widely accepted as the current paradigm in evolutionary biology, and reflects the consensus about how evolution works”.
So how does Plantinga define theism/Christianity?
“When I think of Christianity, I’m thinking of something like the intersection of the great Christian creeds, […] what they have in common, […] you might call this mere Christianity.”Alvin Plantinga (12:10)
Okay, so broadly speaking – Christianity is whatever all Christians (that are not at the very fringe) agree on. Now, Plantinga doesn’t actually tell us what this entails specifically, but I don’t think it would be unfair to say, that this should include at least the following propositions:
- There is some thing we call “god”, that has at least certain characteristics of personhood: An awareness, intentions, (possibly) desires and certain abilities,
- this god is separate of / outside of / above the laws of physics and the purely natural world (in fact, often claimed to be the cause of them), but at least within certain limits capable of influencing or controlling the natural, physical world,
- this god has certain special intentions for, interests in and a particular awareness of life on earth in general and human beings in particular.
Of course, you can be a theist without accepting e.g. point 3, but it’s difficult for me to see, how it would make sense to call yourself a Christian (except maybe in a cultural sense) without accepting all three of those, so I will assume Plantinga holds these views at least in some form.
“And when, and if you take a look […] at these four theses [of Evolution], the first three are pretty obviously compatible with that.”Alvin Plantinga (12:48)
Well, yeah, compatible – but again, that’s completely useless. We can’t disprove the existence of something with absolute metaphysical certainty – that’s like Philosophy 101! On the other hand – if Christianity were true,
- the earth (and the universe) could be a mere 6000 years old,
- Adam and Eve could have been real people,
- humans and other animals would not have to be related,
- all species could have been created separately and instantaneously without the need for a gradual, step-by-step process behind it.
On naturalism however, there would have to be some kind of natural, unguided process (ultimately reducible to the laws of physics) that gives rise to the enormous biological complexity we observe today. Christianity and Evolution might not be logically inconsistent, but we have no reason to expect a mechanism like evolution under theism. No Christian (as far as I know) predicted an evolutionary process based on their Christian beliefs (until Darwin came along with evidence, and then the churches were the first to denounce his thesis vehemently), whereas naturalists like Lamarck already proposed evolutionary explanations before Darwin, and even ancient Greek “proto-naturalist” philosophers (such as Anaximander of Miletu) proposed ideas similar to evolution way before Darwin came along – opposing philosophers like Aristotle, who repeatedly explains biological matters by invoking divine design.
Naturalism predicts the existence of natural, piece-by-piece processes behind any complex system, whether that’s atoms, all of chemistry, the first replicating molecules or biological creatures, up to phenomena like the human mind. This means (from a Bayesian point of view), evolution is strong evidence for naturalism, it raises the probability that naturalism is true, and hence by necessity it reduces the probability that theism is true. That’s how evidence works.
If theism is true, why do we find that the world looks exactly the way it needs to look if naturalism were true? Of course, theists can give ad-hock rationalizations for that, but what they can’t do is make testable predictions based on their beliefs. Naturalists can. This is the argument Plantinga should be concerned about – not whether evolution outright disproves theism with metaphysical certainty. No observation can do that, which is why theism is semantically void. We all agree that the natural world exists (well, most of us do, if you don’t you’re in serious trouble) – if I can’t distinguish between that and the proposition that there exists something else in addition, I can and should (based on simple probabilities) reject that claim outright.
So, what about point 4 then?
“Is Darwinism incompatible with theistic religion? And a large number of people think so. A very large number of people say that it is. People both weigh to the left on the theological spectrum, and also to the right on the theological spectrum.”Alvin Plantinga (13:40)
Yes, because for all practical purposes, “Darwinism” is again strong evidence against theism. We simply wouldn’t expect something like the modern evolutionary synthesis to flawlessly work, if theism were true. That’s why even people on the “left on the theological spectrum” have difficulty grappling with that – as does Plantinga, as we will see. He claims:
“If God, if we have in fact come to be by virtue of evolution, by way of evolution, then it would’ve been by God’s guiding this whole process. Directing it, orchestrating it, okay? So what’s not consistent with Christian belief is the claim that evolution and Darwinism are unguided.”Alvin Plantinga (18:36)
This… doesn’t make any sense. Darwinism – if Plantinga means the modern evolutionary synthesis – is the process that does the guiding. That is the whole point of the theory! Evolutionary theory describes the processes that guide evolution. There is absolutely no reason, let alone need, to postulate any kind of additional guidance on top! And if there is a guiding intentional force behind these mechanisms, we would have had no a priori reason to expect them to use the purely physical mechanisms of evolution!
Plantinga quotes Dawkins on this point:
“All appearances to the contrary, the only watchmaker in nature is the blind forces of physics, albeit deployed in a very special way. A true watchmaker has foresight; he designs his cogs and springs and plans their interconnections with a future purpose in his mind’s eye. Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind, and no mind’s eye. It does not plan for the future. It has no vision, no foresight, no sight at all. If it can be said to play the role of watchmaker in nature, it is the blind watchmaker.”Alvin Plantinga quoting Richard Dawkins (20:24)
That’s the argument: We know the guiding processes of evolution and these processes can be demonstrated to occur and perfectly explain all the diversity in biology, and they are completely not what we would expect if there was an additional intentional guiding force behind them. The processes themselves have no goal, no purpose, no intention. This is strong evidence for naturalism and against theism.
Instead of replying to Dawkins’ point directly, Plantinga goes off on a tangent on irreducible complexity, the proposition put forward by creationist Michael Behe, that certain features in biology are too complex and interdependent to have come about by gradual, unguided evolutionary processes as those described in the modern evolutionary synthesis. They can not be reduced to prior developmental stages that would be necessary for an unguided evolutionary process. Classic examples of supposedly irreducibly complex organs are e.g. the blood clotting system, the immune system or the bacterial flagellum. And of course, naturalism predicts that those can’t be irreducible complex, which means their individual components must have come about individually and to the advantage of the organism.
So here’s Ken Miller, a catholic evolutionary biologist who’s a firm believer in guided evolution, showing exactly how all these systems can be reduced, completely dissecting all proposed examples of irreducible complexity and exposing it as the creationist propaganda that it is:
It’s the only argument people opposed to the theory of evolution have ever really had, since the scientific consensus was established: “X is too complex to have evolved”. Biologists have taken them up on their claims and time and again, they have been shown to be false. Every testable prediction the modern evolutionary synthesis makes has been confirmed. Plantinga says:
“Michael Behe has talked about irreducible complexity. […] Well, one of the things that Dawkins does is to try to show that these arguments don’t really work. And sometimes he’s reasonably successful, and other times, seems to me he’s not very successful at all.”Alvin Plantinga (24:15)
Not very successful? Care to give examples? No? Are you actually going to invoke lousy creationist arguments and not even try to back them up?
“Another thing is he does thirdly, is to make suggestions as to how it did, in fact, happen. How it could be that these and other organic systems have developed by unguided evolution.”Alvin Plantinga (24:40)
“Suggestions”. Well, yes, that’s all he possibly could do – we don’t have a gapless perfect record of the complete evolutionary ancestry of every single species, and we never will – but these suggestions are backed by evidence: comparative anatomy, genetics, fossils… Dawkins is not just throwing vague theses around. And irreducible complexity claims these features couldn’t possibly have evolved without intentional guidance – so a good suggestion whose feasibility is established by evidence is exactly what he needs to give. So how does Plantinga sum up the situation?
“But the principle form of argument for the conclusion, the basic conclusion here, is that evolution reveals a universe without design. […] We know of no other premise [than]: “We know of no irrefutable objections to its being biologically possible that all of life has come to be by way of unguided Darwinian processes”. All right? That’s the premise. Therefore, here’s the conclusion: “All of life has come to be by way of unguided Darwinian processes”. All right? If you think about that argument […] it is a horrifyingly lousy argument.”Alvin Plantinga (25:06)
…the fundamental principle behind the scientific method is a lousy argument? Are you kidding me? You defend an unfalsifiable assertion by saying, the very thing that establishes a leading theory in science – namely its falsifiability and our lack of success in falsifying it despite tenaciously attempting – is a lousy argument?
If the only way to defend your position is not just to point out that science isn’t perfect and doesn’t know everything with 100% certainty (which is of course totally true, albeit a pointless argument), but instead claim the fundamental principle behind the scientific method is “horrifyingly lousy”…. I’m at a loss for words. Why is Plantinga considered to be a serious philosopher?
Still on Dawkins refuting intelligent design:
“It basically goes like, “It hasn’t been proven impossible, therefore it’s true.” “Alvin Plantinga (26:25)
Oh, the irony…
“So for example, suppose last year I come to the Chairman of the Philosophy Department and said, “The President wants me to receive a $50,000 a year raise.” Well, naturally the Chairman might want to know, why I thought that was true. You know? He’d say, “Really? What makes you think that’s true?” I’d say, “Nobody has proven it impossible.” “Alvin Plantinga (26:30)
Yes, and if you had actually tried to prove it impossible, and tried every conceivable way (for example by just asking the president, obtaining his emails to HR etc.), you’d be fully justified in believing that he does want you to get a raise, up to the point where assuming the contrary would be absurd. This is what irreducible complexity tried: disproving the modern synthesis. And they failed every time, as did every other attempt to falsify the theory – of which there have been a lot, because it actually makes predictions that can be tested. Therefore, the theory is most likely true, up to the point where denying it becomes absurd. That’s how science works, and it works that way because that’s how probability works.
Why do I feel like I need to explain that to a supposed serious philosopher?
So next he instead tries to argue, that maybe mutations aren’t actually random in a way that contradicts Christianity. Of course, under naturalism they aren’t random in the sense, that they are perfectly determined by the laws of physics. But that’s not what we mean by random. What matters with respect to the question here is, whether we can find any kind of direction, intention or otherwise discernible pattern in mutations. And we have found some patterns, and obviously they are due to purely chemical reasons and with no signs of divine (or otherwise) intention. So in what sense could mutations be non-random such that we had a sign of intelligent guidance? How about this:
“Ernst Mayr says, “When it’s said that mutation or variation is random, the statement simply means that there is no correlation between the production of new genotypes and the adaptational needs of an organism in a given environment.” […]
[Elliott Sober] says, “There is no physical mechanism, either inside organisms or outside of them, that detects which mutations would be beneficial and then causes those mutations to occur.” […] If these genetic mutations are random in that sense, that’s perfectly compatible with their having been caused by God. So the point is that a mutation accruing to an organism is random just if neither the organism nor its environment contains such a mechanism. Okay. So, as far as I can see, the claim that evolution demonstrates that human beings and other living creatures have not, contrary to appearances, […] been designed [is] not a part or a consequence of the scientific theory of evolution just as such.”Alvin Plantinga (28:10)
Yes, it is. The “scientific theory of evolution” is concerned with any and all mechanisms guiding evolution, none of which show any kind of goal, intention, design or other signs of an intelligence. And this is incompatible with theism in the sense, that it is not, what we would very likely expect to see under theism. Therefore, again, it is strong evidence for naturalism, because naturalism requires that mutations would have to be random – in the above sense – and show no signs of intent or goal. So why doesn’t Plantinga think, that this is incompatible with god? He doesn’t say. I assume god just guides evolution in a way indistinguishable from exactly what we would expect from the purely natural laws of physics, because, I don’t know, free will or something.
Again, yeah, you can play that game. They’re not incompatible from a strictly logical perspective. But what you’re doing then is a posteriori reasoning, rationalizing away a fact that would not have been predicted by theism and is necessarily entailed by naturalism. The probabilities still shift massively in favor of the competing hypothesis.
“As a scientific theory, it doesn’t address such questions as whether or not evolution has been guided by God, for example.”Alvin Plantinga (29:40)
Yes, it does. The theory of evolution encompasses any and all mechanisms guiding evolution, that is the whole point of the theory. If we would find any kind of intentional goal or other sign of intelligence in mutation rates, that would impact the current modern evolutionary synthesis and it would have to be improved and modified accordingly (basically to include god’s intentions, whatever they might be). Irreducible complexity really would disprove the theory of evolution.
Now, to be fair, Plantinga points out that it’s not really a clear cut matter, which exact propositions are part of “the scientific theory of evolution” and which aren’t. But I assume that the mechanisms guiding evolution certainly should be – that’s what e.g. natural selection is, after all. Also, Plantinga wants to argue specifically for Christianity as opposed to naturalism. Naturalism definitely does address the question, and the success of evolutionary theory is strong evidence in its favor.
And now we’re at the point where Plantinga completely jumps the shark. When discussing the result of polls that show, that roughly half of the US population does not accept evolution, Plantinga finds someone to blame:
“Well, why is this? I think the reason why this is, is that we are regularly told by the experts, Dawkins, Dennett, Gould, Simpson, Ayala, and others, that current scientific evolutionary theory asserts or implies that the living world is not designed, and that the whole evolutionary process is unguided. When the experts tell us this over and over again. The National Association of Biology Teachers, until 10 years ago, officially described evolution as, on their website, they described it as, “An unsupervised, impersonal, unpredictable, and natural process.” Unsupervised, impersonal, not supervised, not orchestrated by God or anyone else. Okay? If we’re regularly told by the experts that in fact the theory is a theory of unguided evolution, it’s no wonder that many Christians believe that. The experts are, after all, experts. And if they do believe it, then it’s not surprising that they don’t want it to be taught as a sober truth in public schools.”Alvin Plantinga (33:15)
Evolution, according to the modern evolutionary synthesis, is an unsupervised, impersonal process, not orchestrated by god or anyone else. We do not see any sign of orchestration or supervision anywhere and the theory is concerned with exactly the processes that guide evolution. But the insane part is, that he seems to think scientists and naturalists are the ones who went out of their way to hammer Christians with the claim, that religion and evolution are incompatible. No, they’re not, nothing is strictly incompatible with theism – if you want to imagine some guiding force on top of the known, natural evolutionary processes, go ahead. But the 40-odd percent of Americans doubting evolution certainly didn’t get the idea “religion vs. evolution” from reading Dawkins, Gould or Dennett et al – most of these authors only became vocal about religion precisely because of the alarming number of creationists in the US and their attempts to remove evolution from classrooms!
It’s the ministers over there, that preach that god created the earth in 7 days, 6000 years ago finishing with Adam and Eve in the garden of eden and that therefore evolution is a lie and leads to eugenics and abortions and contradicts the bible, which is the infallible word of god. Ken Miller seems to wholeheartedly agree where the problems are if you look at his above talk. He actually examines the claims made by creationists – and they’re not being made by the kind of Christian who would accept a guided form of evolution. Without creationists, I doubt Gould and Dawkins would have become as prominent as enemies of religion as they have – in fact, Gould is the one who proposed science and religion as non-overlapping magisteria with different domains of applicability and thus necessarily compatible. And most of Dawkins work is explicitly battling creationism and explaining evolution to people whose only knowledge about evolution comes from their ministers’ malicious misrepresentations thereof.
To put the blame on naturalists is to completely reverse the causal arrow here.
“Clearly, there are questions of justice here. Would it be just to teach in public schools positions that go contrary to the religious beliefs of most of those who pay for those schools? The answer seems to me, fairly clear. That would not be just. That would not be proper. And therefore, in a way, these people like Dawkins, Dennett, Ayola, Ayala, and the rest, who trumpet the incompatibility of current evolutionary theory with religious belief, with Christian belief, as far as that goes, with Jewish and Muslim belief as well. In a way, they’re doing science a real disservice.”Alvin Plantinga (34:30)
So let me get this straight: if scientific findings and conclusions contradict commonly held religious beliefs, then we should not teach those findings in science classes and scientists should not point that out? If creationists believe in a young earth, then science class is not supposed to teach them the contrary? That would not be “proper“? Then what’s the point of science class at all, if not to teach science?
How can anyone take Plantinga seriously?
I would seriously urge Plantinga to take some advice from his fellow Christian Ken Miller. In the above video, he not only explains why it’s an incredibly bad idea to take evolution out of the school curriculum, he also argues beautifully for why pragmatic naturalism is a necessary aspect of the scientific method.
So we finally come to Plantinga’s actual argument against naturalism:
“I want to argue that in fact there is conflict between naturalism and evolution. […] It’s not that it’s logically impossible that they both be true, not that kind of conflict. They could both be true. It’s rather that one can’t sensibly believe them both.”Alvin Plantinga (36:50)
Oh, so in the case of Christianity, mere compatibility is good enough, but in the case of naturalism we broaden our definition of incompatibility. Noted.
“I’m going to use the letter N as an abbreviation for naturalism, and E as an abbreviation for the thought that we human beings and all of our faculties and parts have come to be by virtue of the processes pointed out or mentioned in current evolutionary theory. And R is the proposition that our cognitive faculties are reliable. Here, by cognitive faculties, I just mean things like memory and perception, […] that of logical or a priori intuition, […] sympathy, whereby you can tell what somebody else is thinking and feeling. […] For them to be reliable is for them to produce in us, for the most part, true beliefs. […] They don’t have to be 100 percent reliable to be reliable, but […] as a general overall figure, maybe three out of four beliefs have to be true for the whole battery of cognitive faculties to be reliable. […]
Okay, so then, then we’ve got premise one: The probability of R, given N and E [is] low.
The second premise is, if you accept N and E, and you also see that one is true, then you have a defeater for your belief in R, […] where a defeater for a belief is some other belief you’ll acquire, such that as long as you hold the second belief, you can no longer rationally accept the first. […]
Then the next premise is, one who has a defeater for R, for the proposition that one’s cognitive faculties are reliable, has a defeater for any belief she takes to be produced by her cognitive faculties. And of course, that would be all of her beliefs, right? One’s beliefs that are produced by one’s cognitive faculties. […] And of course, one of those beliefs is N and E itself, right?
And hence, if you believe N and R, N and E, you’ve now got a defeater for N and E, right? Well then, it looks as if N and E is self-defeating. It provides the defeater for itself. […] It is self-referentially incoherent. But the bottom line would be that it’s not rationally acceptable, you can’t rationally accept it. You can’t sensibly believe both N and E.”
Alvin Plantinga (37:50)
Now this argument has several flaws, some of which are given here on wikipedia. The immediate responses that come to mind are:
- Our cognitive faculties are unreliable and here is a list of documented, well studied and known ways in which human cognition is typically error prone.
- That’s why science places such a high emphasis on empiricism, replication and predictions and has such a low regard for anecdotes, eye-witness accounts and memory. The scientific method allows us to compensate for our cognitive shortcomings.
- The probability of R (being generally sufficiently reliable to be trusted, even if prone to errors and unless having reason to think otherwise) specifically for our reasoning apparatus given N and E is still extremely high, for the simple reason that it is its only advantage. If it wouldn’t allow us to draw by-and-large accurate conclusions about our surroundings (especially in predicting the behavior of others), they would confer no advantage and wouldn’t be selected for. If our cognitive faculties would cause us to mostly come to wrong conclusions, we wouldn’t be able to survive for long. That’s why psychiatry is a thing.
- More generally – if we wanted to be accurate, we’d have to decompose R into a whole list of individual cognitive faculties, all of which have different probabilities to be correct, some of them rather large and some of them smaller – not surprisingly, some of our mental faculties are rather reliable (facial recognition, simple causal reasoning, intuitive physics) and some of them are hardly (intuition for probabilities, hyperactive agency detection,…). Also not surprisingly, things like facial recognition, causal reasoning and an intuition for simple newtonian physics are extremely advantageous, whereas e.g. estimating probabilities isn’t exactly a natural thing to do – as opposed to going with our gut instincts, which are tuned for survival “in the wild” and terrible in our modern situations, when e.g. estimating your chances in gambling.
- Every imaginable hypothesis about cognitive faculties being optimized for other advantages (happiness, ethics,…) than their being accurate would be just as valid under theism – if they’re advantageous, why shouldn’t a god design our mental faculties to confer us with those advantages instead of accuracy? If you want to claim god prefers accuracy above all else, why do we have all of these stupid cognitive biases?
- Just pragmatically, the argument gets us nowhere. Assuming we can’t trust our mental faculties to (in general and in specific domains) come to the right conclusions – all we can do if we want to discern truth from falsehood in any way is to look at what’s more probable. And the plain fact is that they seem to work. Even if the probability of R given N and E were incredibly low – it wouldn’t lead to a defeater, since no matter what epistemology we follow, some sufficient version of R has to be true from the start or we can’t form any beliefs whatsoever. It would “only” be strong evidence against N and E.
- In particular, without R we couldn’t believe Plantinga’s argument in the first place. And if we accept that R is true, and we seem to have to, its probability given N and E without R as an assumption doesn’t matter anymore with respect to R, as long as it’s not 0 – and I don’t think Plantinga wants to claim that. If R is an axiom, or for other reasons true a priori, its probability is exactly 1.
So in conclusion: Plantinga’s arguments why evolution and theism are compatible are either trivial (under one definition of “compatible”) or invalid/ignorant/missing the point (under another definition), he gives us no reason why theism should be plausible (not to mention more plausible than naturalism), fails to counter any one of the discussed arguments why theism is implausible and his argument why naturalism is supposed to be incompatible with evolution doesn’t work and applies just as well to theism. In the process he shows a tendency towards creationism and eliminating evolution from the school curriculum and betrays ignorance about the scientific method and evolutionary theory.
And yet people take him seriously. Why?