Plantinga’s Tiger and Other Stupid Shit

In the course of composing my critical series of Timothy Keller’s Reason for God, I noticed his reliance on that awful philosopher Alvin Plantinga at a key point, warranted an article all it’s own. It’s an argument you’ll have heard many times before, and will continue to hear from science-illiterate Christians. So it’s worth having a dedicated article just on that, which you can reference, make use of, and cite.

Boasting Plantinga as his authority, Tim Keller claims that, “If we believe God exists, then our view of the universe gives us a basis for believing that cognitive faculties work, since God could make us able to form true beliefs and knowledge” (p. 140). This is actually illogical. We know for a fact that our cognitive faculties are poor…they do not work very well. So badly designed are they, that it took us thousands of years to invent “workarounds” for our failing faculties, technologies that “bypass” their defects, and help us learn about reality contrary to our biologically evolved inability to do so. Language. Logic. Formal mathematics. Scientific method. Critical thinking skills. Even physical instruments, which correct for countless limits and defects in our sensory and cognitive abilities. These we all had to invent. None of them were communicated to us by God. We had to come up with them ourselves. And because a god didn’t help us find them, it took over a hundred thousand years to do it. That makes exactly zero sense on Keller’s thesis. But it is exactly what we should expect on mine: there is no God.

Parsing the Reality

Keller quotes the weirdo atheist philosopher Thomas Nagel saying he must “follow the rules of logic because they are correct—not merely because I am biologically programmed to do so” (p. 137). Nagel and Keller are both confused. We aren’t biologically programmed to follow the rules of logic. We had to invent that, after thousands of years of failing with our innate abilities and seeking better ones. And we have to keep re-installing it manually, into every child born, because every child born, is born without it. Logic is a human-made software patch that corrects for our brain’s lack of intelligent design. Logic is not an evolved ability. We trust it, because it works. That’s how we discovered it; and why we chose eventually to elevate it over all the other things we tried, that don’t work.

I’ve explained already before how we build from raw uninterpreted undeniable experience, to test until we trust the analytical reliability of logic, and then the inductive reliability of empirical methods—which are continually evolving as we learn from their failure the flaws in old scientific methods and invent new or added methods that correct for those flaws. All we need in order to be able to leverage this, is the ability to experience what happens when we try one method or another. Our access to that experience does not have to be 100% reliable. We know for a fact it’s not. But we can still discover good outcomes in the aggregate: any method that always does better than chance, when it can be applied over and over again, eventually gets to the truth. Just as a die we get to keep rolling, will eventually roll a six. And through this process, as we detect the unreliabilities, we learn ways to control for them, and work around them.

We discovered that the illusion of water on the horizon was a defect in our visual faculties, for example, by walking up and discovering by a separate system (touch) that there was no water there. A little more inquiry and testing, and we discovered what we see as a distant lake, is actually light bending and refracting in the heated air just above a hot surface. Not because we were intelligently designed to learn these things. Not because we biologically evolved the ability to learn these things. But because we biologically evolved some cognitive resources that were only just reliable enough that we could use those resources to discover actually reliable cognitive skills. Skills we were not born with, did not evolve, and were not taught or imbued with by any gods. Skills we only stumbled upon after thousands and thousands of years of trial and error.

Evolutionary Epistemology Is Internally Coherent

Keller is badly trying here to deploy the inept Christian apologetic called the Argument from Reason. I’ve already thoroughly refuted far more sophisticated versions of that argument than Keller’s. So I hardly need revisit it much here. But I’ll quote a good summary of my point from The End of Christianity (p. 301; scholarship cited there):

[H]umans evolved to understand the world they are in, not the other way around. Even then, the universe is so difficult to understand that hardly anyone actually understands it. Quantum mechanics and relativity theory alone try the abilities of someone of above average intellect, as do chemistry, particle physics, and cosmological science. Thus neither was the universe designed to be easily understood nor were we well designed to understand it. We must train ourselves for years, taxing our natural symbolic and problem-solving intelligence to its very limits, before we are able to understand it, and even then we still admit it’s pretty darned hard to understand. If you have to rigorously train yourself with great difficulty to understand something, it cannot be said it was designed to be understandable. To the contrary, you are then making it understandable by searching for and teaching yourself whatever system of tricks and tools you need to understand it.

Our ability to learn any system of tricks and tools necessary to do that is an inevitable and fully explicable product of natural selection; that ability derives from our evolved capacity to use symbolic language (which is of inestimable value to survival yet entails the ability to learn and use any language—including logic and mathematics, which are just languages, with words and rules like any other language) and from our evolved capacity to solve problems and predict behaviors (through hypothesis formation and testing, and the abilities of learning and improvisation, which are all of inestimable value to survival yet entail the ability to do the same things in any domain of knowledge, not just in the directly useful domains of resource acquisition, threat avoidance, and social system management).

It’s thus not at all hard for me to explain how we evolved lesser abilities, useful to our survival, that we could use to discover language, math, logic, and science, and it’s not at all hard for me to explain how we are able to know language, math, logic, and science are better than what we were born with, simply by using the imperfect abilities we were born with. To the contrary. It’s hard for Keller to explain why we were not just “born with knowledge of the universe or of formal mathematics or scientific logic or with brains capable of far more rapid and complex learning and computation.” Why did we have to invent all those things? Why are our inborn faculties so defective and unreliable that we even needed to invent those things? Atheism explains this perfectly. Evolution science explains it easily. Theism doesn’t explain it at all.

Thus, when Keller asks, “if we can’t trust our belief-forming faculties to tell us the truth about God, why should we trust them to tell us the truth about anything, including evolutionary science?” (p. 138), the answer is so obvious I cannot fathom how it eludes him. If Keller could show any possible way we could have actually evolved to falsely believe the findings of evolutionary science, he might have a point. But he can’t. So he doesn’t. Just because we evolved to mistakenly believe in gods and spirits (due to the survival-utility of agency over-detection), it does not follow that we evolved to believe evolution by natural selection. That wouldn’t even make any sense. Nor is there any evidence for us to experience that would support such a strange notion. Unlike there is for agency-overdetection…where now we know that defect is working in our brains, so we can install a “software” patch of critical thinking that can work around it and correct for it.

Therefore, Keller cannot argue that our belief in evolution is untrustworthy, from the fact that our belief in gods and spirits is untrustworthy. Or any other discovered defect in our cognition. In fact, that analogy isn’t just false, it’s completely illogical. We readily and naturally see spirits everywhere (we have to unlearn that, by training or enculturation). Whereas the fact that evolution took so long to discover, and went against every instinct we had, entails we did not evolve to believe it. We had to overcome numerous inborn cognitive defects to actually realize it was true.

What we instead evolved to believe, is things supported by evidence, through a variety of imperfectly logical mechanisms, because the ability to acquire and change our beliefs when encountering evidence is useful to survival. But nature is not a master intelligence, it’s a drunkard’s walk. So it didn’t install in us a perfectly logical mechanism for reaching conclusions from evidence. It gave us a chance stew of ad hoc, cobbled-together, roughly-good-enough mechanisms, because those were the ones it randomly stumbled upon, and their survival utility ensured their propagation. But once we had those mechanisms, we could do what nature could not: we could intelligently use them to discover better mechanisms. Hence language, logic, math, science. All human inventions. All non-existent for nearly all the hundred thousand plus years of our species’ existence on earth.

Want to know why we trust logic more than faith now? Because we observe—with our mediocre, inborn faculties that help us survive by responding to evidence—that one (faith) fails countless times, while the other (logic) almost never, or indeed never, fails. The proof is in the pudding. We could not have landed a man on the moon “by accident.” So we know our invented methods work. Whereas we could never have landed a man on the moon with just our biologically evolved faculties.

Believing in Evolution with Evolved Brains Is Reasonable

This confusion between what we were born with, and what we had to invent (and then started trusting because we observed it worked better) runs rife throughout Keller’s illogical discussion of epistemology. The methods we eventually discovered and observed to work—language, logic, math, and science—we chose to trust because we observed their superior effectiveness in discovering false beliefs and so many otherwise-unexpected true beliefs. And our ability to observe that, is entirely explicable as an ability we acquired for its survival advantage. It’s exactly the same talent we evolved to help us discover better ways to make spears or process food or figure out an enemy’s plans or carry water with us. The exact same faculty. We simply need no other, to be able to observe the relative effectiveness of different methods at figuring things out about ourselves and the world.

So we actually have a really good reason to believe in evolution now, despite our poorly evolved cognitive abilities. Whereas this is not the case for believing in gods and spirits: neither abundant evidence nor any improved methods we’ve learned support believing in them, so the “evolved error” explanation remains the best in their case, for precisely every reason not applicable to evolution by natural selection. Knowing evolution was true, required a vast acquisition of numerous different lines of evidence, the invention of science and logic, and the previous discovery of several otherwise unknown facts, and even then it was really hard to get people to believe it. Because their brains are broken. They have shitty faculties. Until they care about fixing them. Then they will fix them. And then they’ll get it.

Keller might try to argue that even our rough and shitty evolved evidence-detection abilities might be too shitty to trust in anything. But he has exactly no reason to believe that. We can’t have evolved to be our own Cartesian demons. Because we can’t be completely fabricating our perception of the world and still survive. We must be able to ascertain reality through observation, otherwise reality would kill us. True, evolution won’t produce perfect reality detectors, and indeed that’s what we observe: our evolved abilities are flawed and limited and imperfect, in exactly the ways evolution predicts (which is evidence against Keller’s God and for evolution). But once we became intelligent enough for that itself to be an advantage to survival, we intelligently invented software patches to fix our failing evolved faculties. And even then it took us tens of thousands of years of failing at that, before we discovered good patches. And we only discovered them because observation confirmed they failed less often.

This is why we trust science. Not because we evolved to be scientists. But because we evolved to observe enough signals from the world to know when something works and when it doesn’t; and then invented a way to use that talent, to develop better ways to find out how reality works; which we confirmed by observing them work. God was never involved. He did not design us the way we should have been. We had to redesign ourselves. And he did not reveal anything at all to us about the need or means to so redesign ourselves. We had to figure it out entirely on our own, randomly trying alternatives for eons upon eons, until eventually by inevitable random accident we hit upon design fixes that worked. This demonstrates the absence of God, not his existence.

Plantinga’s Tiger

Which gets me to Plantinga’s tiger.

Keller relies a lot on Alvin Platinga for his illogical arguments on this. But Plantinga has no expertise in evolutionary science; and his arguments are illogical and unscientific, indeed hilariously stupid. He thinks, for instance, that it would be more likely for evolution to program us with a zillion random commands (like “always run from tigers”) than a single general intelligence algorithm that would be able to figure out what things kill us (instead of having to have been genetically programmed to know that in advance); and would be able to figure out when we should run from a tiger or stand our ground and kill it for food or to save our village.

Not only is Planting’s idea impossible—his model would require billions of trillions of years to even get to any point of being useful; whereas the correct model, of what actually happened, is vastly more probable—but it’s also illogical: a vast system of fixed commands to always run from tigers et al. would hugely reduce our ability to survive, relative to a peer who got a simple general intelligence instead; so evolution will always select the latter over the former.

This is why:

General intelligence is far simpler (it does not consist of a zillion one-line “if, then” commands) and scaleable (you can start with a crude general intelligence and leverage it smarter and smarter with successive adaptations). So it’s far easier to stumble on by accident; it’s therefore inherently vastly more probable as an outcome of natural selection. But it also has two huge advantages over Plantingian programming: it can save us from new and unanticipated dangers, and as such can save us from potentially infinitely many dangers, whereas Plantingian evolution is totally incapable of that (instead it requires killing a lot of people just to get a single “if, then” advantage); and a general intelligence can diversify our response to dangers in ways that greatly increase our differential reproductive success over versions of us that can’t.

For example, general intelligence can give us an array of behavioral options (run, fight, hide, shout, fart, trap it, tame it, play dead, throw a stick, distract it with a slab of meat), and can also learn to figure out which is needed or likely to be effective. Unlike the Plantingian tiger-phobe, someone who is merely just smart can encounter a tiger and not only not die, but end up with several days’ worth of food and a new cool cloak for winter. Which is, again, a huge advantage to survival. Plantinga’s guy, would inevitably get selected out of the gene pool, replaced by his far more capable peers.

So as an argument, Plantinga’s tiger is fantastically stupid.

That’s not the only idiocy in Plantinga’s garbage philosophy. Throughout all his work on this (which he calls the Evolutionary Argument Against Naturalism):

  1. Plantinga ignores the difference between the biology and the technology of reason. The former is what our brain does; the latter is all the tools we developed to improve on what the brain does, such as mathematics, logic, and science. Those things have to be installed culturally. Because they aren’t in us biologically. They were not selected by evolution. They were selected by the rudimentary human intelligence that evolution gave us. Just as eyeglasses, telescopes, microscopes, and IR cameras allow us to improve on our biologically innate vision, so also logic and science do the same for our otherwise unaided reasoning. Hence we did not “evolve” telescopes. We evolved the ability to make tools. Then we made telescopes.
  2. Plantinga conflates different kinds of faculties. My eyesight and visual processing is one faculty (e.g. my ability to see you and gauge your distance and size); my ability to process diverse information and thereby conclude that you cannot hide inside a lunch box is another faculty altogether. Plantinga makes no distinction, and thus is incapable of ever having a scientifically credible account of our cognitive faculties. Which is why he has never published a single paper on the evolution of cognition in any science journal dedicated to actually scientifically studying the evolution of cognition. By making novel scientific assertions about cognition, he’s pretending to be an expert in cognitive science. With exactly no degrees or publications in cognitive science. I’m relying on actual experts. If Plantinga were quoting actual expert conclusions in that field, and then identifying fallacies or defects in their evidence, that would have merit. But he doesn’t. His model of evolution doesn’t come from anywhere in science; it even contradicts all the science there is, without interacting with any of the actual science. Philosophy that is that science illiterate, is garbage.
  3. Plantinga leans his entire argument on a single bifurcation fallacy: that naturally evolved faculties are either reliable or not. When in fact they have degrees of reliability; our faculties are neither 100% reliable, nor 100% unreliable. Plantinga never accounts for this. Anywhere in the whole of his case.
  4. Plantinga also conflates different kinds of knowledge. Knowing how far away you are from me and how large you are relative to a lunch box, is different from knowing that you therefore can’t hide inside a lunch box; which is different from knowing how to calculate the geometric volume of a lunch box; which is different from knowing how to predict what Newtonian stress the lunch box can withstand from internal pressure as I try to squeeze myself into it to hide there, before it bursts apart; which is different from knowing the laws of pressure and temperature and volume; which is different from knowing why those laws actually govern the material the lunch box is made of; and so on. Each of those kinds of knowledge took a different sequence of biological adaptations (binocular vision; language processing; world-model building) and a different sequence of skill discoveries and observational achievements (it took many different people centuries of fiddling to go from “I can’t fit into a lunch box” to “the reason I can’t fit into a lunch box is the electromagnetic force”). Plantinga ignores all that. Which means his apologetic ignores reality. Like all apologetics does.

For an example of another inept apologist deploying ridiculous Plantinga-style arguments against the natural evolution of our faculties, consider an example I thrashed years ago:

Another absurdism comes when, following Plantinga pretty closely, [Victor] Reppert offers a single imaginary “example” of how we could evolve a “useful false belief.” I already refuted the concept of such arguments earlier (cf. e.g. AfRF). But here I want to focus on how Reppert dooms himself from his own Lack of Imagination—in other words, a failure to think his own scenario through. His example goes like this (please resist laughing): “If the chief enemy of a creature is a foot-long snake, perhaps some inner programming to attack everything a foot long would be more effective from the point of view of survival than the complicated ability to distinguish reptiles from mammals or amphibians.”

That’s right. That’s exactly what he says. … [The] example is absurd. Follow me here. I have “some inner programming to attack everything a foot long.” Okay. Stay with me. What sorts of things are a foot long? Hmmm. Well, sections of my arms and legs. So I’ll be busy hacking off my own limbs the moment I have the strength to act on my insane “inner programming” proposed by Reppert. Good grief, don’t let that man design robots! And what about snakes that are only six inches long—or two feet long? I guess they get to kill us.

Okay, suppose for some zany reason all snakes are only exactly one foot long, and we also evolved the ability to discriminate our own limbs from all those other foot-long objects we are supposed to attack. How would we ever get out of the house? Or pass a tree? It is a cliched horror to break rocks at Leavenworth all your life, but Reppert apparently thinks it would be a greater survival advantage than human reason to actually like breaking foot-long rocks at Leavenworth all our lives—indeed, to do nothing else but!

I hardly need go on. The absurdity of his scenario is palpable. There is no way evolution could ever produce (especially in a population) such fatal “inner programming.” Therefore, Reppert’s example is defunct. His “perhaps” is really a “definitely no.”

Can we give Reppert a hand here and maybe come up with some example that isn’t ridiculous? I doubt it. It will always be a more efficient use of resources (energy, time, risk, and tools) to avoid attacking all non-threats and to attack all actual threats—including entirely new and unanticipated threats. And the only means by which an organism can maximize efficiency in this respect is to optimize its ability to categorize and discriminate objects and events. There is literally no other way. So how can Reppert advance any argument to the contrary?

I’ll tell him how he could do it. For it is true that there is a threshold beyond which discriminatory abilities become detrimental or needless (i.e. the gain in efficiency is negligible or even reverses, into a loss in efficiency). That is why when we look at a leaf we see a patch of green and not a trillion-billion individual photon-cell reactions. That is why our eyes can’t see bacteria and why our brains always devote most of their limited attentional resources to a relatively confined region of our visual field (otherwise we would never need eyes that move in their sockets). So there is a sense in which the basic idea behind Reppert’s argument is true: at some point the efficiency-gains of discriminatory ability diminish, and then cease to overcome the concomitant increase in physiological detriment (from an ever-larger and more-energy-consuming brain, for example).

The question to ask then is: When? At what point does this happen? At what threshold between discrimination and efficiency does reason become impossible? These are scientific questions, and can only be given scientific answers. I await Reppert’s peer-reviewed scientific research paper on the subject. Until then, this is just special pleading. Indeed, when Reppert concludes that “it is far from clear that a general ability to learn what is true will be helpful from an evolutionary standpoint” … I can only suppose he has some kind of mental cataracts obscuring his view. Learning isn’t useful? Of course it is. Far from being “far from clear,” this is not only clear to the rest of us, but blindingly obvious.

And that’s what’s wrong with all arguments like this. Evolution simply does not work the way Plantinga thinks or says. It never could. Evolution also did not give us logic or science. We gave ourselves those things. All evolution gave us was a rudimentary set of skills that made it possible for us to give ourselves those things. And evolution did not give us those rudimentary skills so that we could discover the better ones. It gave us those rudimentary skills because they were useful to survival. That they could then also be used for finding better skills is simply an inevitable and unavoidable byproduct of having them. And all the evidence we observe, confirms exactly that. Just as we did not evolve to play complex music on violins; we evolved hands, which necessarily entails the ability to play complex music on violins. Plantinga doesn’t understand this. Because he’s an ignorant hack who doesn’t know jack about how evolution works.

So Keller needs to get off that wagon.


  1. Justin Legault July 25, 2017, 7:23 am

    Hi Richard,

    Excellent article!

    I had a question concerning Josh Sommer’s comments to you about Plantinga and just epistemology in general.

    Firstly, I don’t know what a Calvanist truly is, which is what Josh is correct? Unless I am mistaken. Calvanists is a denomination in Protestantism I think but what are the big differences between them and say, Anglicans, Lutherans, Catholics? I heard they have the “Once saved, always saved” doctrine. So what once you are saved, you can commit any sin, and be forgiven?

    I feel like Josh heavily relies on the fact that he presupposes gods existence and admits our cognitive faculties are not perfect, thus, we are surely wrong about evolution. But then presupposes god for all his arguments, even though that argument could be used against him as well? Wouldn’t that be special pleading or confirmation bias on his part? I mean, I’m kinda confused as to why he thinks he has a key in the epistemological train when he admits human cognition’s are poor.

    One of his comments was “Atheist saying there’s no evidence for god is like throwing someone in water and claiming he doesn’t see the water” I know, cringe worthy fallacy right there -> Perhaps, non sequitur?

    That’s not evidence for god, it’s evidence for water. It reminds me of the “Look at the trees” argument.

    Well that’s just evidence for trees not a god, let alone your specific god of your specific denomination.

    He also says Genesis 2 is a better explanation than Naturalism…I almost ripped my hair off…We actually have evidence for Naturalism unlike Genesis…

    Is he desperately trying to debunk evolution because he knows it destroys Biblical Creation? No Adam and Eve = no Original Sin = No need for a savior (Jesus died for nothing), which is what the whole soteriological of Christianity relies on.

    He then mentions a false dichotomy (Either choosing Atheism or Jesus) He mentions all positive points for his imaginary friend, but then only bad connotations for atheism, as being depressing, no coping method whilst believing in Jesus gives comfort.

    Sure comfort is nice, but doesn’t make it true.

    I do believe he his sincerely convinced of what he believes. However, I don’t think his conclusion he reached is justified. He talks about Jesus as if he actually has a relationship with him, yet admits our cognition’s are poor…So how can he know what he believes is true and not misled? He doesn’t seem to see this. He’s essentially saying “well Richard’s and other Atheists cognition’s are poor thus most likely false. But mine are also poor, but I KNOW mine are correct because, well, Jesus”

    I feel like Josh relies on presuppositionalism and fallacies for his arguments. He calls you a hack, likely because you have the only peer reviewed work against the Historicity of Jesus, and that probably aggravates him to no end, that not only the Jesus of the gospel is false but that there’s a possibility the ‘historical’ figure might be as well.

    Am I wayyyyy off on my representation of Josh’s beliefs? Is my reasoning sound? I’m just very confused as to how he can’t see his arguments are flawed from the very first premise.

    1. There are too many varieties of Calvanist now for the term “Calvinist” to even indicate anything anymore. So I sympathize. And I have no idea which sect or faction of Calvinism Sommer is into. You’d just have to ask him what its peculiar doctrines are.

      Sommer actually challenged my science-based claim that our faculties are enormously defective. He even made fun of my massive citation of examples. He’s evidently not into scientific facts. Which rules him out as a legitimate party to any debate about reality.

      So I don’t know how to answer your question. Someone who delusionally thinks they are under water and we just refuse to see the water is not someone we can have a rational conversation with.

      Likewise someone who is completely out of touch with facts and reality. For example, his claims about atheism are false.

      1. Justin Legault July 25, 2017, 10:34 am

        Thank you for your link about Atheism+Health and happiness.

        I completely agree with you about his misrepresentation and purposeful ignorance of what atheism is. Atheism is simply a rejection of the claims made about a deity due to lack of reliable evidence. It says nothing about our morals, values, etc. those are separate issue.

        I do know he’s really into Ken Ham according to his posts. That should be enough to know how illogical and unscientific he truly is. He truly rejects and/or finds scientific finds untrustworthy but the bible as infallible….I think I’m going to cry..

        How can he assert that our faculties are defective, ergo scientific facts are flawed and thus wrong. Then he concluded god did it, when his faculties should also be defective no? Unless he thinks being ‘saved’ means he has true knowledge from Jesus compared to us godless simpletons? I don’t necessarily agree with absolute truths, however in my opinion, science is the best and most consistent method we have at finding what is true. All he has is blind faith which is not a reliable path to truth, nor can he demonstrate any truth, only assert and proselytize.

        I want to have a PM discussion with him. However, I will refrain from having one. Mainly because his arguments are flawed and he doesn’t understand that even when you show him it is erroneous.

        I feel like he’s a troll but that he also thinks he’s the enlightened one, more importantly, he would be wasting my time, because no matter the evidence you provide, empirical, reliable, peer reviewed etc, he’s contractually as an adherent obligated to reject it and he clearly demonstrates that on every post.

        He just frustrates me that there are people like that.

        It slows down our advancements about how the real world works. I know we’re moving in the right direction, but it’s not going fast enough.


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