On Presuppositionalism

In “Unmoved Mover“, I wrote about the presuppositional argument used by some modern Christian apologists. In this post, I want to say some more about presuppositionalism.

The presuppositionalists have a point in this sense and in this sense only: a worldview is worth being held only if it is possible to reason consistently from that worldview given its own starting principles. If those principles lead inevitably to their own negation, then that worldview is self-contradictory and must be discarded. This is correct as far as it goes. Where presuppositionalists go wrong is in the assertion that Christianity is the only worldview that possesses or could possess this kind of consistency. This assertion is both fantastically arrogant and unequivocally false.

Here’s an example of a worldview that genuinely is inconsistent. The laws of thermodynamics say that, over time, entropy increases to a maximum. The higher-entropy configuration – the more “chaotic” state – is always more likely. Yet our universe as we currently observe it is in a low-entropy state, with plenty of organized pools of energy available to do work.

As we proceed toward the future, the overwhelmingly likely outcome is that entropy will increase. But the laws of physics are time-symmetric: they make no distinction between past and future. Therefore, if we look back into the past, it is also far more likely that entropy was higher back then than it is now. Granted, it’s unlikely that entropy would spontaneously decrease, from a chaotic past to an orderly present. But if we assume that the past had less entropy than the present, we have an even more unlikely configuration to explain – we’re making the problem worse, not better. Applying the laws of thermodynamics in a naive way, then, leads to the conclusion that everything we observe might be a rare, but statistically inevitable, random fluctuation that produces a temporary island of order in the midst of pure chaos.

And the smaller the island of order, the more likely it is that it could arise through random fluctuations in chaos. Thus, compared to the odds of producing an astronomically vast, orderly cosmos, it’s much more probable that random fluctuations would produce a single, isolated observer – a disembodied brain, say – floating in the void of chaos and falsely imagining a whole world surrounding it. This is called a Boltzmann brain.

But there’s a problem. If we are Boltzmann brains, then nothing we believe about the world can be trusted – including the very observations which led us to suspect we might be Boltzmann brains in the first place. The circle of logical contradiction is closed: observations lead us to infer conclusions which in turn lead us to doubt and disbelieve those observations. The Boltzmann-brain worldview falls apart from its own inconsistency. (This is not to say it’s necessarily false – maybe we are Boltzmann brains, there is no way to disprove that – but even if it is true, we could never know it, because the hypothesis itself undercuts all possible basis for believing it.)

The way out of this dilemma is to assume that the evidence is reliable, and that our sensory perceptions and memories of the past reflect a real external world with a real history. This starting point leads to a position which does not contradict itself.

The atheist viewpoint runs along similar lines. Its intrinsic starting point is that the universe is a collection of physical things which exist independently of us, the behavior of which is governed by orderly, immutable principles which we call natural laws. Although the cosmos is complex far exceeding our ability to fully conceptualize it, and although our senses are imperfect and can be misled, we still have the ability to perceive reality with a fair degree of accuracy, to discover its governing principles, and to make inferences about how events will unfold in the future. In other words, we are rational creatures who can learn how the world works.

Contrary to what presuppositionalists claim, this view is consistent. Accepting it as true does not lead to any self-contradiction. (The usual response – that evolution would not produce rational believers – I dealt with in 2006, in “Are Evolved Minds Reliable Truth-Finders?“)

Of course, this by itself does not prove that atheism is true. This is a trivial conclusion, since there are infinitely many consistent worldviews, but only one world. A worldview might be entirely consistent with itself and still be false because it does not reflect the way the world actually is. But self-consistency is the starting hurdle that any worldview must clear before we begin examining it to see whether it corresponds to empirical reality. Atheism is one of the consistent worldviews worthy of consideration, and the attempts of religious apologists to rule it out of hand from the beginning – or to make the ridiculous claim that theirs is the only possible consistent worldview – cannot be sustained.

About Adam Lee

Adam Lee is an atheist writer and speaker living in New York City. His new novel, Broken Ring, is available in paperback and e-book. Read his full bio, or follow him on Twitter.

  • Joffan

    Re: Boltzmann brains – what’s all this “we” nonsense? I am a Boltzmann brain; you are a figment of my randomly-fluctuating delusions of sensory input, as is my impression that I am typing a reply comment to the article…

    Hmmm, why bother? well, I’ll fool myself that I’m pressing the “Submit Comment” control anyway…

  • Dennis

    It’s funny that you posted this today, because I’m listening to a debate on exactly this argument. The Christian debater claims atheism leads to self-defeating skepticism, consistently saying that because our worldview leaves open the possibility that the sun won’t rise tomorrow (however small that possibility), we can’t function in our everyday lives. Presupposition seems to be created as the last area to flee for apologists without denying large swaths of modern knowledge, basically claiming God exists in their worldview/opinion because they assume She does. Its hard to argue against that point, but it does nothing to prove existence. They overstep their bounds when they go on to claim other worldviews are inconsistent. What work of fiction is more inconsistent than the Bible?

  • http://stargazers-observatory.blogspot.com/ Stargazer1323

    Dennis,

    I find the fact that a Christian would argue that an atheistic world view leaves the possibility open for the sun not to rise tomorrow very funny. Assuming that the atheists in question accept that the world works the way that we have observed it to work, they should always wake up with complete certainty that the sun will rise because of its location and the rotational patterns of the Earth. However, if the stories of the Christian god are to be believed, they cannot wake up to that same certainty every day because their god is an arbitrary and capricious deity who could simply choose to stop the sun rise.

    I loved this post because of the fact that basing one’s viewpoint on what is stable and observable in our world is more rational and more sustainable that assuming variables, such as omnipotent deities who could change anything about our world on a whim, that cannot be proven. I ultimately abandoned theism for that very reason – a simple understanding of the world and its processes instills in me more wonder, more peace, and more purpose than belief in a deity behind it all ever did. As science and human reasoning continue to reveal more knowledge about how the world works, I hope that more people will begin to see the world in the same way, diminishing the need for religion to explain the world to them.

  • NoAstronomer

    Blah! Joffan beat me to it! (or so my delusions of sensory input tell me)

  • Dennis

    One thing I’d like to add, or make more explicit, is the arrogance Ebon mentioned. Their implicit argument is that we all have a Christian worldview (the only one possible), and we are just denying it. It goes back to their similar claims that we are just denying god, instead of truly not believing in her. This argument stretches back to before Christianity existed; early man must have had a Christian worldview before he even knew Christianity. Its all part of common thread in Christianity and many other religions to be expansive, to expand even into how everyone understands the world. It seems inevitable that the god-of-the-gaps would eventually be reduced to only in our own heads. Odd that they admit it in a roundabout way though.

  • mike

    The first time I read about presuppositionalist apologetics, I thought, “How refreshing! At least they are finally admitting that their reasoning is circular.” So it has that going for it too.

  • Samuel Skinner

    Don’t worry- if something prevents the Sun from “rising”, we will all be killed by it any way. Black hole, nova, wandering star, variable physics… it won’t be fun. However, the physicists will love it. Given what we know about over surroundings, the odds are obsenely low- someone would have noticed something like that in our vicinity.
    Unless he is arguing the Earth will stop rotating, which will also kill use (massive deceleration at the least). Or did he not mean his statement literally.
    Besides, I’m pretty sure it was an Aztec belief that the Sun might not come back.

  • Christopher

    I wonder what Descartes would say about the Boltzmann Brain: I think therefore there exists the possibility that I am – assuming that the thoughts in question are really from me?

    But seriously, I often wonder: just how much of what we call “reality” is *real* and how much is merely a perception of our own minds.

  • Brit-nontheist

    Christopher:

    I wonder what Descartes would say about the Boltzmann Brain: I think therefore there exists the possibility that I am – assuming that the thoughts in question are really from me?

    Descartes may have said something very interesting about the Boltzmann Brian, but whatever it would have been would be unhelpful because of rather fundamental error in his reasoning. “I think, therefore I am” presupposes the “I am” it is meant to show; the phrase, without that presupposition, can only read “there is thinking going on, therefore something exists”. I know that’s a bit off the point, but it’s an interesting diversion nonetheless, I think.

  • Christopher

    “Descartes may have said something very interesting about the Boltzmann Brian, but whatever it would have been would be unhelpful because of rather fundamental error in his reasoning. “I think, therefore I am” presupposes the “I am” it is meant to show; the phrase, without that presupposition, can only read “there is thinking going on, therefore something exists”. I know that’s a bit off the point, but it’s an interesting diversion nonetheless, I think.”

    I think he was a bit hasty to jump to conclusions as well – personally, I would have preferred “I am, therefore I think” due to the fact that those thoughts have to come from somewhere: and since I have no basis for belief that they come from an external source, I must assume that they come from me.

    Of course, if some one pointed out a mechanism that produces thoughts independent of the *I* but still creates the illusion that it’s their origin this whole statement would be falsified. However, to my knowledge no one has yet done that – so I’m safe in my reasoning (at least for the time being anyway…).

  • Mrnaglfar

    I love philosophy; it’s like science without all that pesky data and evidence getting in the way.

    Descartes also tried to reason his way into the existance of a god. I went over some of his stuff and found it fairly (very) unconvincing. He jumps from “I think therefore I am” into other assumptions that could certainly be doubted, according to him.

    Evidence, is of course, absent.

  • Alex Weaver

    But seriously, I often wonder: just how much of what we call “reality” is *real* and how much is merely a perception of our own minds.

    This strikes me as an artificial and arbitrary distinction.

  • http://elliptica.blogspot.com Lynet

    [The] intrinsic starting point [of the atheist viewpoint] is that the universe is a collection of physical things which exist independently of us, the behavior of which is governed by orderly, immutable principles which we call natural laws.

    I prefer the starting point “consilience is an epistemic indicator”. I suspect it’s more accurate. Human beings notice patterns — this is the way we are. As a result of noticing patterns, we formulate laws. Are there laws? I suspect it depends what you mean by the notion. Are there patterns in our experience? I’m going to go with ‘yes’, and I’m going to say that’s not a presupposition, it’s an observation*. The presupposition (if there is one) has to do with the idea that it can be useful to extrapolate from the patterns we see, whether that be an extrapolation forward in time or outward in space. Exactly how to extrapolate, however, belongs more to the realm of ‘knowing how’ than to the realm of ‘knowing that’, if you ask me. It’s not based on a presupposition, it’s just, you know, human behaviour. Does that make sense?

    I prefer this starting point because I think it’s clearer that I haven’t defined God out of it. There’s no explicit methodological naturalism. God just fails to show up.

    *I know it’s possible to find patterns falsely, but if you start saying that our ability to detect false patterns is completely wrong, you’re getting towards the point of doubting your ability to reason, which really gets you nowhere.

  • Samuel Skinner

    Why does it matter if reality is real? There has to be something real at the bottom- otherwise we wouldn’t be thinking. So what if we can’t prove that our reality is the real deal? We treat it as such and it works. Not to mention that the alternative resembles madness.

  • Christopher

    Alex Weaver,

    “This strikes me as an artificial and arbitrary distinction.”

    My mind perceives light waves reflecting off an object and interprets the data as color, but does that mean color really exists or that only the concept of color as data interpretation exists? Also, since two people looking at the same object may see a different color (one may see deep blue, another black, etc…) one has to ask whether there is truly objective means of determining color at all.

    If we can’t even reach a conclusion about the reality of physical things (like color), we’re a long way off from determining objective reality of anything else (such as values, the role of society, the workings of thoughts, etc…) and must settle for subjective views on them – as we have no choice but to do so.

  • OMGF

    …one has to ask whether there is truly objective means of determining color at all.

    By the wavelength of the EM waves.

  • Steve Bowen

    In the beginning, God created a nice simple little garden with a couple of self aware inhabitants in it. Due to a small oversight with an apple tree, expecting to see something beyond the garden they peeked over the garden wall, compelling God to create an apparently flat landscape to banish them to while they bred a race of inquisitive descendents. Annoyingly these people explored the extent of this landscape, so in the interests of topological economy he folded the earth around itself to make the world spherical. Bugger me if the brats didn’t start looking out into the night sky and expecting something more than a black sphere with holes in it. For centuries God has been re-building the universe to appease the expectations of his insatiable offspring (including falsifying billions of years of cosmic history) and he’s getting fed up with it.
    All this would be true if I hadn’t personally created this whole damn universe thing a minute ago.

  • Christopher

    OMFG,

    “By the wavelength of the EM waves.”

    But color isn’t the EM wave, but rather the *perception* of the EM wave in question: two people can look at an object emitting the same EM waves and see two different colors.

  • Brit-nontheist

    Christopher:

    But color isn’t the EM wave, but rather the *perception* of the EM wave in question: two people can look at an object emitting the same EM waves and see two different colors.

    Can they? Or is it simply that they articulate the colours as different? We are after all as constrained by our language as much as our senses.

    I believe that unmediated knowledge of reality is impossible (insofar as we cannot remove from the process the interpretations made by our own senses) but that doesn’t, I think, mean that the actual reality is rendered subjective (though to some it extent it may be rendered inconsequential) by our inability to reach it. Therefore I agree with you that the EM waves exist independently of our perception, but colour does not. I see colour as our mediated perception, the EM wave the reality behind it which we can’t experience abstracted from our senses (though an interesting point to the argument is the use of artificial senses such as meters which present EM waves as numbers rather than colours).

  • OMGF

    But color isn’t the EM wave, but rather the *perception* of the EM wave in question…

    No, it’s not. Color is determined by the wavelength of the wave. That is an objective measure of color. We objectively say that “blue” fits in to a certain wavelength band and any EM waves that fall within that wavelength band are blue, whether you see blue or not.

  • Christopher

    Brit-nontheist,

    “Therefore I agree with you that the EM waves exist independently of our perception, but colour does not. I see colour as our mediated perception, the EM wave the reality behind it which we can’t experience abstracted from our senses (though an interesting point to the argument is the use of artificial senses such as meters which present EM waves as numbers rather than colours).”

    That’s what I was trying to tell OMFGm – what we call “color” is only an interpretation of the real thing being perceived (the EM wave), but apparently he thinks that the EM wave itself *is* the color. Apparently he can’t differentiate between the physics and the metaphysics of a thing…

  • OMGF

    Sigh.

    Color is determined by wavelength. You have it backwards. I don’t care if you see a wave with a wavelength of 500nm as being red, it clearly is not, because it is outside of the range for “red”. You asked if we could objectively measure color…we can, and I’ve shown you how. You simply can’t countenance that someone else might be right and you might be wrong. Troll.

  • Thumpalumpacus

    Naw, Chris isn’t a troll; he’s just persnickety. Plus, many things in life, colors included, are such that while numbers maydefine them, numbers cannot convey their essence. There is nothing in any particular wavelength that makes everyone universally think, “red”. Nor does your mechanistic explanation address the perceptual and experiential side of things at all, which is the issue Chris is trying to explore, I think.

  • OMGF

    The point is, Thump, that in response to whether we could objectively determine color at all, I provided a way. If one wants to move the goal posts now and suggest that the experience of color can not be objectively defined, that’s one thing, but it’s not the statement that I answered. We can, and do in some situations, objectively determine color from the wavelength, as color is determined by the wavelength.

  • Steve Bowen

    I think the subjectivity of the experience of colour is well known and well argued. The fact that we can measure wavelengths and assign numbers we agree on to define them, is an objective way of describing the universe to each other. However it does not mean that our individual experience of colours has to be the same or that our emotional responses correspond. Materialism allows for us to expect the universe to be independently quantitively measurable but does not prescribe our qualitative perceptions which (to me anyway) are still obscure.

  • http://elliptica.blogspot.com Lynet

    Ah, but, while we can’t be sure that our experience of colour is the same, we can still say that there is some objectivity to our perception of colour insofar as it is possible for people to agree on terms for particular colours and then independently agree as to what colour things are. Joe and Mary might not know that they’re seeing the same thing when they both see a red shirt, but they can agree, independently and objectively, that the red shirt is the same colour as a red apple.

  • Christopher

    OMFG,

    “Color is determined by wavelength. You have it backwards.”

    No, color is just an interpretation of a wavelegth – if a mechanical eye was programmed to do so, it could translate a wavelegth human eyes tend to interpret as “red” as being “blue” or “purple” or “orange” or anything else we can set it to.

    “I don’t care if you see a wave with a wavelength of 500nm as being red, it clearly is not, because it is outside of the range for “red”.”

    It’s outside the range for “red” as perceived by the average human eye, but who’s to say that there’s no eye that won’t perceive an entirely different color upon looking at the same wavelength?

    “You asked if we could objectively measure color…we can, and I’ve shown you how. You simply can’t countenance that someone else might be right and you might be wrong.”

    You provided an objective means of measuring a wavelength, not this thing we think of as “color.”

    “Troll.”

    Are the insults really necissary? One could just as easily call you a “troll” if you posted this in a forum full of post-classicalists.

  • Thumpalumpacus

    OMGF –

    Indeed, you are correct in the objective view. I merely think you two are arguing at cross-purposes. To be honest, I have a deeper gripe with Chris’s statement that ”
    If we can’t even reach a conclusion about the reality of physical things (like color) . . .” for color obviously has a physical reality, if nowhere else, then in our brains where synapses flicker with molecules to convey the experience of “red”. A frequency may not convey color per se, but energy; but those molecules are what it means to see red, and they are as physical as the stars.

  • OMGF

    Once again Christopher, wavelength determines color. If we went by what you assert, then when a color-blind person sees gray instead of the color they are blind to, that it actually is gray they are seeing, and not red or blue or green or whatever. This is simply not the case. Objectively, red falls in a certain range, as does blue, green, ultraviolent, infrared, etc. There is no way around this fact. It doesn’t matter if someone outside the average sees it differently or not, because we can and do set objective limits on the wavelengths that make up the different colors.

    You provided an objective means of measuring a wavelength, not this thing we think of as “color.”

    Wrong again. Wavelength is integrally tied to color. What you are talking about is what we perceive, not what is actually there. If you want to contend that our perceptions are subjective, fine, I have no quarrel with that. But, that’s not what you stated, and you insist on continuing to state the same thing over and over even though you are flat wrong.

    Are the insults really necissary? One could just as easily call you a “troll” if you posted this in a forum full of post-classicalists.

    Whatever. You fit the definition of troll. The only reason I responded to this at all was because I didn’t realize it was from you. I didn’t read the name attached to the comment before I had already written my response. Once I was in, I figured, “In for a penny, in for a pound,” so to speak. Your assertions are dead wrong. If, for instance, my eyes were specially able to see infrared radiation, and it appeared to me as blue, would that make it blue? No, it would still be infrared.

  • Christopher

    OMFG,

    “Once again Christopher, wavelength determines color.”

    No, wavelength determines what the eye perceives – which is in turn interpreted as an image; color being a part of the image. The wave doesn’t carry some color essence attatched to it: it simply exists and then, after it’s observed and interpreted by an outside party, it has a color ascribed to it.

    Unless you can prove that color exists as some Platonic ideal just floating in the ether somewhere (good luck trying to do that), this is the only logical explination for its existence – the concept exists because we perceive and conceive it into existence.

    “If we went by what you assert, then when a color-blind person sees gray instead of the color they are blind to, that it actually is gray they are seeing, and not red or blue or green or whatever.”

    Quite frankly, to the color-blind observer in question the object *is* grey – as that’s how their nervous system interprets the light waves emminating from the object. The thing called “color” is all in the mind of the beholder: the light waves may very well be real (assuming we aren’t all trapped in Descartes’ Dream – in which case both your argument and mine go right out the window), but any information about them is gathered by individual perception and thus is open to interpretation.

    “Objectively, red falls in a certain range, as does blue, green, ultraviolent, infrared, etc.”

    If you refer to the color wheel, it’s based on how a typical *human* eye perceives light – which is in and of itself a subjective standard: why use the human eye as the standard instead of some other animal’s eye, or a mechanical eye that’s far more sensitive to certain lightwaves than our sensory organs are? In the end, we just accept it as the standard because that’s the perception of light most common to us – if the overall population perceived light differently, we would use a very different standard!

    In the end, we still have no truly objective view of reality – only concepts thereof. And this argument about the nature of “color” is but one aspect of the broader debate concerning what is/isn’t “real.”

    “Whatever. You fit the definition of troll.”

    That can be argued based on context – likewise *you* could be called a “troll” under different circumstances. You way wish to think twice before throwing stones from a glass house: those “stones” can do just as much damage to your credibility as that of the other person…

  • http://whyihatejesus.blogspot.com/ OMGF

    Christopher,

    No, wavelength determines what the eye perceives

    No, the physiology of your eyes determines what your eye perceives.

    Unless you can prove that color exists as some Platonic ideal just floating in the ether somewhere (good luck trying to do that), this is the only logical explination for its existence – the concept exists because we perceive and conceive it into existence.

    Wrong again. Color exists because different EM waves have different wavelengths. This has nothing to do with Platonic ideals. There are objective measures for color and you are incredibly ignorant about them and arguing like a troll. I suggest you actually look it up and try learning about them instead of simply toeing your relative reality line.

    Quite frankly, to the color-blind observer in question the object *is* grey – as that’s how their nervous system interprets the light waves emminating from the object.

    Our perceptions of reality don’t shape the reality around us.

    The thing called “color” is all in the mind of the beholder

    I’d like to see a color-blind person get out of a ticket for running a red light by claiming that the light was gray. To that person, it was gray, so they can’t be ticketed for running a red light that wasn’t red.

    If you refer to the color wheel, it’s based on how a typical *human* eye perceives light – which is in and of itself a subjective standard:

    Actually, it’s now based on wavelength in some applications which is objective. Face it, you’ve lost. Whether anyone really decides by wavelength or not, the fact remains that we *can* make objective determinations of color by wavelength. But, keep trolling, because I’m done with your ignorant obstinance.

    In the end, we just accept it as the standard because that’s the perception of light most common to us – if the overall population perceived light differently, we would use a very different standard!

    Even if we called “red” “der” instead, it would not change the fact that we can and do label a range of wavelengths as “der”. Slapping a label on something may mean that the name was subjectively chosen, but it doesn’t mean that the thing being described is subjective.

    In the end, we still have no truly objective view of reality – only concepts thereof.

    We might not be 100% objective, but it’s not near as dire as you make it out to be. We subjectively see the sun move around the Earth, but we objectively measured and found that the Earth moves around the sun (in the most parsimonious sense). We may subjectively bite into a pepper and find it hot, but we can objectively measure the capsins in it and find out how hot it is.

    That can be argued based on context – likewise *you* could be called a “troll” under different circumstances.

    Why am I not surprised you are once again pulling out the relative reality card? On this board, you come here to be obstinate, to argue (not to debate or discuss), you disregard the tough questions only to simply repeat your arguments ad nauseum. Hell, the blog owner has advised us all to ignore you, and as I said before I would have had I noticed that you had written the post I responded to. You may have the last ignorant word, where you will undoubtedly simply repeat the same crap as if I had said nothing, just as you ignored some other points I made, like about infrared light, etc.

  • Christopher

    “Color exists because different EM waves have different wavelengths. This has nothing to do with Platonic ideals. There are objective measures for color and you are incredibly ignorant about them and arguing like a troll. I suggest you actually look it up and try learning about them instead of simply toeing your relative reality line.”

    And as I said before, those measures are based on how a typical human eye perceives various wavelengths of light – not any intrinsic value of the light itself (as there’s no intrinsic “redness” or “blueness” or any other color imbedded in light itself).

    I see that nothing productive will come of this conversation (you’ll continue to insist color exists outside ourselves, I’ll try to explain that this epistemology is flawed, you’ll continue to insist it exists outside ourselves – repeat ad infinitum).

    “Our perceptions of reality don’t shape the reality around us.”

    I beg to differ – perception has a powerful effect on how one behaves in life, thus causing him to shape his reality around him; within the perameters of his predispositions, of course.

    “Why am I not surprised you are once again pulling out the relative reality card?”

    Maybe it’s because I openly admit that I don’t believe in such things as absolute “truth” – only ideas of truth – and hold that much of what we call “reality” is just an artificial construct? Come on, I pretty much gave that away when I admitted to being a Nihilist!

    “Hell, the blog owner has advised us all to ignore you, and as I said before I would have had I noticed that you had written the post I responded to.”

    Both you and Ebonmuse are entitled to your opinions of me, but remember that they are just that – opinions – and have no more significance than what you ascribe to them.

    “You may have the last ignorant word, where you will undoubtedly simply repeat the same crap as if I had said nothing, just as you ignored some other points I made, like about infrared light, etc.”

    I skipped over them because the point was moot: if infrared light was visible to the naked eye, we’d likely base our color system on that instead of what we think of as “visible” light. And I already stated that color is simply based on how light is peceived – be it infrared or anything else – so it would have been pointless to state it again…