I was banned from Uncommon Descent this morning for reasons unknown (though here is a plausible hypothesis). At the time of my banning, I was in the midst of a long discussion of absolute certainty and whether it can rationally be claimed. Since I can’t continue the discussion at UD, I’ll start a thread here instead and solicit the opinions of the very smart locals here at TSZ.
The question is whether there we can be absolutely certain of anything. I am not speaking of absolute certainty in the colloquial sense (“I’m absolutely certain I left the keys on the counter!”), but in the precise sense of 100.0% (unrounded) certainty, with literally no possibility at all of error — not even a trillionth of a trillionth of a trillionth of a percent chance of error.
It seems obvious to me that we cannot rationally claim that kind of certainty because we know that our minds are fallible. We know that we can be mistaken without realizing it, even in cases where we feel absolutely certain. The example I used at UD was the certainty many 19th-century scientists felt, before Einstein, about the “self-evident” absolute and distinct nature of space and time.
Given the ever-present possibility of error, I think it’s pure hubris to claim absolute certainty of anything – even something as seemingly inescapable as Descartes’ famous cogito.
Not surprisingly, the regulars at UD disagreed. Kairosfocus in particular was in hysterics over the supposed dire consequences of my view. What surprised me, though, was that Lizzie also disagreed with me. I am interested in hearing more about why she disagrees, and also in what the rest of you think.
Is absolute certainty possible? If so, what can we be absolutely certain about? What (if anything) justifies absolute certainty? I look forward to your answers.
I’ll start by quoting Lizzie:
Lizzie,
This is more or less a restatement of Descartes’ cogito. And clearly you believe, as Descartes did, that to deny your own existence is an absurdity. I agree that it is an absurdity. Our reasoning tells us that it makes no sense. However, I also believe that our reasoning is fallible, and that any diagnosis of absurdity is therefore not absolutely certain.
If we can’t be absolutely certain that something is absurd, we can’t be absolutely certain that it is wrong. Thus I simply don’t see how absolute certainty can be justified, even in the case of the cogito.
The mere possibility that we are mistaken — any nonzero probability, no matter how minuscule — is enough to torpedo absolute certainty. 100.0% becomes 99.99…9%. Absolute certainty becomes almost certainty.
Hi Keith
What are you going to do with all the free time? 🙂
I am very sceptical that philosophy can solve any problem of reality. It may be good at asking questions but… Richard Rorty’s pragmatism makes most sense to me.
I am sure that I am certain that I will die one day? Am I mistaken?
I am with Lizzie. There is a class of statements that if I believe them to be true then they must be true. For example, “I am in pain”. It would nonsense to conjecture as to whether I am really in pain or not. The more interesting question is what kind of statements are these. What are their truth conditions. I confess to finding it very hard to articulate the answer.
is there anything in that class that does not relate to the self and/or personal experience?
Hi Alan,
I’ll go back to my regularly scheduled programming. 🙂 I figured this would happen soon enough, given Barry’s sweaty grip on the ban hammer, so I took full advantage of my limited commenting window.
I would argue that while you can be extremely confident of that, you can’t be absolutely certain, because there is always a possibility, no matter how remote, that you are being fooled. For example, can you really be 100.0% certain, with absolutely no room for any doubt whatsoever, that you are not a brain in a vat, with all of your sensory data being fed directly into your brain by some phenomenal supercomputer? Perhaps brains are immortal in reality but someone wants to fool you, for some strange reason, into believing that you are mortal.
We don’t take this possibility very seriously, obviously, but I also don’t think we can assign a probability of exactly zero to it. It is not impossible, just very, very unlikely.
If it ain’t impossible, we can’t be absolute certain that it isn’t happening.
The possibility is not that remote! But, then let’s say deluded. I can’t consider reliably if I really am deluded. Pragmatically, I test my assumptions against my sensory inputs constantly. I don’t feel the need to worry further.
Alan,
Yes, the tiny difference between almost certainty and absolute certainty has almost no practical effect on how you live your life. That is why it was so funny to watch KF’s hilarious “the sky is falling!” routine. It was completely overblown.
The only practical difference I see between being 100.0% percent certain and merely 99.99…9% certain about something is that in the former case, there is absolutely no need to question yourself or even to consider the possibility that you are wrong.
I think that’s why it’s so appealing to the UDers!
Mark Frank:
Hi Mark,
Might it be as simple as the split between things that depend in some way on external sensory data versus those that don’t?
I would agree that the latter are more certain than the former, but I would still argue that they are not absolutely certain. They are mental phenomena and our minds are fallible.
And while it definitely seems absurd to consider the possibility that we don’t exist, that very absurdity is also dependent on our fallible minds. It seems at least possible, though very unlikely, that it really isn’t absurd at all — it may just seem that way because our fallible minds incorrectly tell us so.
I can’t see how we could ever justify our impressions/sensations/thoughts as absolutely certain given that they are mental phenomena produced by a fallible mind.
After all, in doing so we would be using our fallible minds to decide that our fallible minds are infallible on a particular issue (or set of issues). How could that ever succeed?
While it’s logically possible for a generally fallible mind to be infallible on a particular issue, I don’t see how you could ever prove such infallibility from the inside.
Yes, sometimes UDers and TSZers play ‘intellectual games’ together. TSZ formed largely because Elisabeth Liddle was banned from UD. Almost 700 posts on that ridiculous thread on UD and it seems like Lizzie and keiths enjoyed every moment flaunting their philosophical skepticism there (although I must admit I stand on Lizzie’s side on this one against keiths’ hyper-skepticist anti-realism).
What seems evident from keiths line of skeptical ‘thought’ is its rank probabilism [“100.0% (unrounded) certainty”]. But likely he won’t pause to consider what that ideology of probabilism actually means, and instead revert into skepticism as a way of life, as a worldview. It’s quite a sad story, especially as it hides behind the mask of ‘just properly doing science.’ Human relationships need not stoop (theoretically) to such a low level as keiths has demonstrated in his posts at UD.
“The strongest argument against historical skepticism….the man who doubts the possibility of correct historical evidence and tradition cannot then accept his own evidence, judgement, combination and interpretation. He cannot limit his doubt to his historical criticism, but is required to let it operate on his own life. He discovers at once that he not only lacks conclusive evidence in all sorts of aspects of his own life that he had quite taken for granted, but also that there is no evidence whatever. In short, he finds himself forced to accept a general philosophical skepticism along with his historical skepticism. And general philosophical skepticism is a nice intellectual game, but one cannot live by it.” – J. Huizenga
basically, you’ve engaged in a lengthy exercise in pedantry.
Nothing much else.
I think you’ve painted yourself into a corner. First, you deny the possibility of absolute certainly because if there is one thing you seem to know for sure, it’s that minds are fallible! 😀 Hipsters would like the irony in that! 😀 Second, if you intend for your claim that “minds are fallible” to be taken as a serious assertion about reality (as opposed, say, to “unicorns are white”), then you have implicitly asserted the premise “minds exist”.
In your “brain in a vat” scenario, you have to be careful to define what the “I” is in Descartes’ “I am”. There is the “I” that I perceive, which is the person typing on this keyboard. But then there is the “I” of my brain in the vat. While I can’t be sure of the existence of the first “I”, the perception of the first “I” seems to be contingent upon the existence of the second, underlying “I”, even if that second “I” is completely self-unaware. I can’t be complete wrong about everything unless there is some “I”.
I don’t disagree with keiths on much – I am merely making a distinction (and I am not 100% unrounded certain it is valid!) between statements about the world, about which I would say we cannot be 100% unrounded certain of their truth, and statements that make no sense in negation, which are not, I suggest, statements about world, but merely the necessary conditions of intelligibility in the contexts to which they apply. For example the LNC is not a statement about the world, it is simply a necessary condition of statements about the classical world, for them to be intelligible. It doesn’t apply to statements about the non-classical world, for example statements about the world at a scale in which the concept of simultaneity is itself begged.
Similarly “I do not exist” cannot be simultaneously true and uttered. That’s not “I exist” is a necessarily true statement about the world (you may read it and notice that in later post I am reported dead – it was true, it is still written, but it is no longer true). But it is necessarily true when I say it to myself – but in that context it is not an objectively verifiable truth about the world, but a necessary condition of my being able to make the statement!
I don’t think you are that far apart – there appears to be widespread agreement that we cannot know anything beyond “sum” with certainty [insert joke about self-reference here], but there is a minor argument over what “sum” means.
I can see Lizzie’s point that for some absolutely minimal value of “I exist”, there can be certainty, but this does not even extend as far as “I will die”, nor “I am in pain”. The CNS’s reporting of internal states is also fallible – to quote Tammy Duckworth, “My feet hurt, too.”
Solipsism is just boring.
Well, I find it so. 🙂
Yes, solipsism is boring, and also massively non-parsimonious.
Absolute certainty is common in mathematics.
We can be absolutely certain of the truth of analytic propositions. However, those have no real consequences for the world so I suppose it is an empty uncertainty.
I think Keiths is wrong on quite different grounds. It seems to me that we can be absolutely certain, yet be wrong. That is, “absolute certainty” refers to a psychological condition, not a logical truth condition.
I’m guessing WJM had a field day. “keiths is absolutely certain there can be no absolute certainty”. The Concept Police have described him as a “person of interest” during ongoing investigations.
Nice point, Neil!
Which brings me back to my central point is that certainty is one of the most dangerous things for anyone to have!
Re: your ‘central point’: “certainty is one of the most dangerous things for anyone to have!” – Elisabeth
So is uncertainty just as dangerous or moreso (especially on an everyday life level, which *everyone* here can easily understand and relate to, regardless of their employment, race, religion, gender or vocation)!
“general philosophical skepticism is a nice intellectual game, but one cannot live by it.” – J. Huizenga
Another way to ask the question, Elisabeth: can you give examples of anything(s) you are *not* skeptical about? What are you *not* skeptical about? Answering this will provide an opportunity for you to speak kataphatically where normally (and oftentimes endearingly in the face of IDists/YECs) you speak apophatically.
You do not appear, Elisabeth, to be as (committed) hyper-skeptical as keiths. Perhaps this is a thread for you to actively display your rejection of hyper-skepticism or to show your hyper-skeptical allegiance.
Being on a jury and having personal responsibility for the fate of another person focuses your thoughts on certainty.
Yes. Keith’s arguments pertain to truth, not certainty. Moreover, it is the kind of truth that depends on a view from nowhere, a God’s-eye view of what is really the case. Even if such a view exists, it is pointless to consider, since no one has access to it. So the point he is making is not so much wrong as uninteresting.
I don’t think keiths is “hyperskeptical” Gregory, nor do I differ from him in my view as to how certain we can be about >i>statements about the world.
It is not that I am 100% unrounded certain of some things but not of others. It’s that there are some statements that in my view are not statements about the world” but are necessary conditions of intelligibility.
In other words, I think there is a class of statements that are 100% unrounded certain to be true but those statements are not statements about the world. They are simply the conditions that must be true for what follows to be intelligible.
For example I am 100% unrounded certain that the circumference of a circle is 2pi*r when that statement is made in the course of an abstract mathematical argument (i.e. is not a statement about the world).
However I am not 100% unrounded certain that this circle, on this piece of paper is precisely 2pi*r, not least because pi is an irrational number, but also because even if it wasn’t (and instead I was testing my confidence that the area of a triangle is equal to half the height times the base), there can be no triangle in the world for which this can be ascertained to be precisely true.
In other words, as we say, proof (100% unrounded certainty) is for math and alcohol, not empirical science.
And that is as far as my non-skepticism goes. I will accept a mathematical proof (and any alcohol on offer) but I do not accept any statement about the world with 100% unrounded confidence. In other words, I am uncertain about everthing else.
I also see this as an inaccurate representation of the concept you seem to be addressing Keith. To me, the question is not whether I am absolutely, 100% certain “I” exist, but rather whether what I perceive as “existence” is absolutely, 100% accurate.
I can’t say for 100% certainty that this “reality” that I experience is actually occurring as I experience it. I can’t be 100% certain that any other person is actually real or that anything I interact with is real. As such, I can’t be 100% certain that my perception of my own existence is accurate either.
BTW nihilistic delusions are not unknown – the delusion that one is dead, or does not exist.
Cotard delusions
Mathematical and logical propositions are true or false, not certain or uncertain.
Certainty is an attribute of fact rather than of logical coherence.
I do think it’s interesting, actually, as it has important repercussions, I think for the whole issue of “predictability” and even (whisper it softly) free will.
In a determinist world (which we probably don’t have, but might), there is a God’s eye sense that it is “certain” what the outcome will be. If you ran it twice, you’d get the same answer the second time.
But there is no other sense in which even a determinist world is “certain”, and it’s not even clear to me that the “God’s eye” sense is even coherent.
I’d give keiths a pass on that one. After all, he did have enough doubt to start a thread on the topic where he solicited feedback.
I, for one, do not understand your point at all. Could you please clarify?
Could you elaborate?
It’s just a semantic game. You spoke of certainty about things of the world. I call that fact. Juries are charged with finding guilt with “moral certainty” or “beyond reasonable doubt.” They are dealing with facts about the world.
The law has dealt with lack of mathematical certainty for thousands of years and has evolved ways of talking about degrees of certainty. Since the law deals with life and death decisions, it focuses your attention on how you arrive at certainty.
Propositions in mathematics and formal logic are true or false by definition. Their status is an artifact of language.
I should say that logical propositions are well formed or malformed. Conclusions are correct or incorrect depending on the correctness of axioms or premises.
But if the premises are dependent on worldly facts, the conclusions cannot be certain.
I like it 🙂
Gregory,
I am neither a “hyperskeptic” nor an antirealist. I just decline to make the leap from ‘almost certain’ to ‘absolutely certain’.
That’s an odd thing to say, considering that in the comment immediately preceding yours, I write that
Robin,
That still leaves me a bit unclear. You are saying that your perception of your existence might be inaccurate, but I can’t tell whether you are expressing 100.0% certainty that you do, in fact, exist.
I don’t understand why the theists at UD have such a hard time admitting that there is no absolute certainty. Only God is so gifted. The rest of us have to build our worldviews on faith of one kind or another. Unless someone at UD claims to have had a divine revelation like seeing/touching the resurrected Christ, then they should heed what Jesus said to Thomas:
“Have you believed because you have seen me? Blessed are those who have not seen and yet believe” (Jn 20:29).
Steve:
Attention, everyone:
Steve has spoken. We can all go home now.
Hobbes,
But of course I’m not absolutely certain of that, and have never claimed to be!
But I do (and quite explicitly!) assert that minds exist. I’m just not absolutely certain of it.
First, I’m not claiming that anyone is completely wrong about everything (oh, wait a second, I just remembered Joe G :D). I’m simply saying that absolute certainty is unjustified.
I absolutely agree that for any of us to declare “I don’t exist” would seem absurd. But if we can’t be 100.0% certain of our judgment, then we can’t be 100.0% certain of the absurdity of that statement, which means we can’t be absolutely certain that it is wrong.
You can’t prove your infallibility from the inside, even on such a seemingly obvious question.
Allan,
William and about 18 others. I spent half the thread explaining the difference between asserting something and being absolutely certain of it.
Does “self-existence” have any necessary implications?
I mean, it sounds profound in Latin, but does anything necessarily follow?
Lizzie,
If you’re not 100.0% certain of the distinction, how can you be 100.0% certain of your conclusion?
I still don’t see how you get to absolute certainty from there. Unless our judgments of intelligibility are infallible, they could be wrong. If they could be wrong, then absolute certainty is unjustified.
Yes, if our reasoning is correct. If our reasoning is fallible, we cannot be absolutely certain of this.
Neil,
Not really. In mathematics, the certainty of propositions depends on the correctness of the reasoning that we employ in order to reach them. Unless you can be 100.0% certain of the reasoning, you can’t be 100.0% certain of the conclusions.
In the UD thread (and in the OP here), I emphasize the distinction between feeling absolutely certain and being absolutely certain. The latter requires you to know that you are correct, not merely to feel it.
SophistiCat,
No, my argument is about certainty. I think we can have true beliefs, just not absolutely certain ones.
Objective truth, in other words.
Well, that’s the very point under dispute. To claim absolute certainty is to say that we do have access to it, at least in some limited way. I deny that this is possible, because such access would necessarily depend on our fallible minds.
petrushka,
To which I would add:
If the reasoner isn’t infallible, the reasoning might be wrong (no matter how seemingly obvious), and therefore the conclusions cannot be absolutely certain.
rhampton,
At UD, I argued that absolute certainty is unattainable even for God:
Didn’t we just see that argument used against evolution?
I agree that absolute certainty about facts is impossible. And I also think we can achieve satisfactory levels of confidence. the two are not incompatible.
I wish IDers would distinguish between “probability” as a normalised frequency, and “probability” as a measure of confidence in a proposition.
It would help quite a lot.
Well, to me, if I can’t know, in some absolute, 100% accurate and specific way, what “exist” means, then I don’t see how I can be certain I exist in any meaningful sense.
For instance, I honestly don’t think I can determine, with 100% certainty, that I’m not some NPC in some virtual world a la WJM’s philosophy of LFW (or lack there of).
I understand Descarte’s argument to some extent, but I don’t particularly buy it. I just think that as phrased by some folks – the internal/definitional vs world facts – is a comparison of apples and oranges. We make definitions so we can communicate. Like maps and models, however, I hold that such definitions – even ones of math such as 1+1 =2 – are not the actual territories. They are representative of worldly concepts and I certainly hold that I can never be 100% certain about those worldly concepts.
This is why I said certainty is common. I did not say it is universal. We may well be uncertain about the correctness of some of our proofs. But there is also a lot about which we are absolutely certain.
That’s a bogus distinction. Absolute certainty is not a property of a proposition. It is a psychological condition. If you are talking about “necessary truth” then don’t call it “absolute certainty”.
Neil,
Not unless you are absolutely certain that the reasoning was correct. That’s my point. Fallible minds can never be absolutely certain of their correctness, even if hundreds of them agree about something.
Mathematical truths cannot be held with absolute certainty.
I’m not claiming that it is. I’m drawing a distinction between feeling absolutely certain and being absolutely certain.
The former is purely a psychological state. The latter is both a psychological and an epistemological state.
Under that distinction, you can feel absolutely certain of a false proposition, but you cannot be certain of one.
I am arguing that feeling absolutely certain (the first sense of ‘absolute certainty’) is unjustified, because being absolutely certain (the second sense) is impossible.
Slightly off topic, but I had nothing to do with KeithS banning, it was news to me when Alan Fox mentioned it on my thread at UD. If any of KeithS post were deleted, I had nothing to do with it, and the decision came from someone higher in the hierarchy…
FWIW, I didn’t read most of KeithS nor Kairos Focus’ philosophy discussions. Whatever happened there, I can’t say. I will say I am personally grateful for KeithS participating in my discussions at UD even though we disagree intensely.
The thread that got this philosophical discussion going was my thread
In a meaningless world does truth always have value over delusion. After the first several posts, I mostly moved on.
So, good luck KeithS, thanks for making my discussion over at UD very lively.
==================================
Each venue is organized under a different mission, and UD is organized to serve and support the ID community, thus it is understandable the pro-ID side will be over represented.
However, I think it is not a good policy for IDists never to be seen engaging their critics in venues like TSZ, so I will occasionally drop in.
To that end, I’d like to thank Elizabeth for giving UD authors the ability to start discussions here at TSZ where critics of ID can be given a full hearing without fear of getting banned.
I think it is important both sides of an argument get a representative hearing of their case at least some (but not all) of the time. Elizabeth has made that possible through this venue. Thank you, Elizabeth.
Thanks for the thanks, Sal.
I agree that UD is better off as a venue primarily to serve the ID community, but if people want to have discussions outside that community, I hope they will visit us here. Clearly the balance of membership is the other way round, but this site is not for serving the ID opponent community, but for trying to have discussion between people who disagree profoundly, with as little tribalism as we can manage.