The Myth of Absolute Certainty

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.

109 thoughts on “The Myth of Absolute Certainty”

  1. keithskeiths Post author

    Kairosfocus still hypocritically claims that my position requires the abandonment of logic:

    No no no, they want to play a game with the same name, logic, where when they like it, they use it, but when it points where they don’t want to go, they can discard it.

    He has it exactly backwards, of course.

    At no point in my argument do I abandon logic. I merely claim that logic, like everything else that comes from our fallible minds, cannot be assumed as absolutely certain, and I support that claim using logic. There is no contradiction in that. It’s perfectly consistent.

    KF, meanwhile, does abandon logic when “it points to where he doesn’t want to go”. KF is frightened of the following simple and obvious inference: if I can’t be absolutely certain that my reasoning is correct, then I can’t be absolutely certain of my conclusions.

  2. William J. Murray

    Which brings me back to my central point is that certainty is one of the most dangerous things for anyone to have!

    Ah, there it is. At UD I said that you were exhibiting an almost pathological aversion to the concept of certainty and being able to make true statements about the world. I had suspected this was why.

    You consider certainty dangerous, especially metaphysical or religious certainty; so you avoid it like the plague, even into incoherence.

    BTW, as I said at UD, “I exist” is a statement about the world (the world being the sum total of “what exists”). If you are absolutely certain of “I exist”, then you have made an absolutely certain statement about the world.

    There’s no way out of that. “What is in existence” cannot be anything other than a statement about the world, whatever “the world” is, and whatever “existing” is.

  3. damitall2

    I believe a major difference between the two venues is that people at TSZ are comfortable with entertaining doubts and discussion about their various positions, whereas those at UD are often not.

    I can see no reason for IDists who are confident of their convictions not to express themselves at TSZ. The rules are clearly stated and practical, and are enforced sensibly. They are in absolutely no danger of being banned by the forum owner or her sidekicks, short of posting links to malware or pornography – which, AFAIK, only one person has ever done.
    OTOH, many of us have been silently banned from UD, no reason given. One can only suppose that our posts are so telling, so damaging to ID, that they must be suppressed.
    In my personal opinion, this is but a small step from shooting people for dissent, and I am grateful that demagogues like Arrington and Mullings have little to no actual influence

  4. keithskeiths Post author

    William, to Lizzie:

    You consider certainty dangerous, especially metaphysical or religious certainty…

    That’s because religious certainty is dangerous (besides being unjustified, as my OP shows). It makes people do ridiculous things like flying planes into tall buildings.

    I suspect that absolute certainty is attractive to you and other UDers because if it were ever attained, it would free you forever from having to justify your beliefs. Pesky skeptics are always asking “How do you know that?”, and it would be very convenient for you to be able to brush them off with “This may not be questioned; it is absolutely certain.”

    You’ve described yourself as “morally lazy”. I think it extends to intellectual matters also.

  5. William J. Murray

    keiths,

    I agree that moral and religious certainty is dangerous. However, so is moral relativity and pathological hyperskepticism.

    Your attempt at slandering my character is duly noted.

  6. William J. Murray

    I believe a major difference between the two venues is that people at TSZ are comfortable with entertaining doubts and discussion about their various positions, whereas those at UD are often not.

    Some things are legitimate doubts. UD welcomes legitimate doubt and legitimate differences of opinion with open arms. What it wil only suffer so much of, though, is unyielding hyperskepticism and self-referential, self-denying absurdity.

  7. keithskeiths Post author

    UD welcomes legitimate doubt and legitimate differences of opinion with open arms.

    That made me laugh.

  8. keithskeiths Post author

    William,

    I agree that moral and religious certainty is dangerous. However, so is moral relativity and pathological hyperskepticism.

    Is someone advocating moral relativism and pathological hyperskepticism here?

  9. William J. Murray

    Is someone advocating moral relativism and pathological hyperskepticism here?

    Not advocating; necessarily implying via premises, and exhibiting.

  10. davehooke

    Keith’s point is trivial as far is pertains to the external world. I would rather say that one cannot have “absolute certain knowledge”. I think that is more precise.

    As far as logic and mathematics go, then there is certain knowledge to the extent that the axioms of the system are accepted.

    Regarding mental states, the uncertainty is in the assertion of self, the “I” of the statement.

  11. Allan Miller

    WJM:

    If you are absolutely certain of “I exist”, then you have made an absolutely certain statement about the world.

    Nope. You have made an absolutely certain statement about a perception. “The world” is out there, filtered by our senses and the timeline that our ‘thinking mind’ presents to us (not always sequentially, and not always accurately). While we are conscious, we may not doubt that we perceive a succession of moments that form a narrative. We know because … well, we remember doing so! Just now, I thought it, dammit! But even the conception “I exist” has a time sequence. By the time you become aware of it, it is in the past, along with everything else you remember (or not). It keeps on coming, of course.

    It is, I will admit, somewhat angels-on-pinheads, but such philosophical minutiae form the bulk of your own output also.

  12. davehooke

    To doubt absolute knowledge is simply (philosophical) skepticism. I don’t see that adding the prefix “hyper” is in any way useful.

    The only sense of moral relativism that skepticism necessarily leads to is a descriptive relativism, as a skeptic may still hold that there is a rational basis for resolving moral disagreements.

  13. William J. Murray

    The statement of certainty that “I exist” is necessarily a statement about the world (the sum of all things that exist), regardless of what “the world” actually is, regardless of what “existing” actually is, and regardless of what the “I” actually is.

    One can be deluded about what the world is, about what self is, and about what “existing” means, but in any case, “I exist”, taken as a certainty, is still necessarily a statement about the world and what exists in it, even if self is the whole world (solipsism).

    There are other statements on can be absolutely certain of, such as the LNC (there are no 4-sided triangles) and Royce’s Error (error exists), which are again statements about the world (what exists), regardless of what the world actually is – that is, if one isn’t being pathologically hyperskeptical.

    Statements about perception are also statements about the world, since perception exists, and the world is the sum of all things that exist. The world – the sum of all things that exist – is not just “out there”; indeed – under solipsism, it may not exist “out there” at all – but also includes all existent internal states and perceptions.

    Any internal statements of absolute certainty are also statements of absolute certainty about the world. It cannot be otherwise.

  14. Lizzie

    OK, William, I grant that if “the world” is defined in such a way as to cover single person’s existence, “I exist” is a statement about the world.

    I also agree (as I’ve said) that we can be 100% unrounded certain that it is true because “I do not exist” makes no sense (the subject must exist in order to make the statement).

    Although keiths also has a point – I am not 100% sure that what I wrote above is valid. But I am fairly certain that it is 🙂

    Let me try to state what I am saying differently:

    [In my uncertain view,] we cannot be 100% unrounded certain of the truth of any objective statement about the world, where “objective” means “of, relating to, or being an object, phenomenon, or condition in the realm of sensible experience independent of individual thought and perceptible by all observers : having reality independent of the mind”.

    (Merriam Webster definition 1 b)

  15. OMagain

    For example, when William says that “FSCI/O can easily be calculated” I can be 100% certain that is an incorrect statement.

    This is easy really.

  16. William J. Murray

    Of course we can be absolutely certain of the truth of objective statements about the world: such as, there exist no triangles in the world that have 4 sides. There exists no object in the world that is both A, and not-A, in the same way at the same time. Etc.

  17. Lizzie

    WJM:

    there exist no triangles in the world that have 4 sides.

    I would not call this an “objective truth about the world”> It is simply a violation of the definition of a triangle, which is a figure with 3 sides. Such a figure does not exist “in the world” – it is an abstract concept.

    Any physical triangular object has far more than 3 sides.

    This comes back to the distinction I keep trying to make between objective statements about the world (the truth of which we cannot be 100% unrounded certain), and statements that would be incoherent in their negation, because they are subjective, and/or self-referential, or subjective, or definitional, or provable

    I exist
    This is not a lie
    A triangle is a closed plane figure consisting of three line segments linked end-to-end.
    The area of a plane triangle is equal to half the base times the height.

    In one sense I am 100% unrounded confident that these statements are true, but I do not think they are “objective truths about the world”.

    The sense in which I am not 100% unrounded confident that they are true is that it is possible that I have got them wrong.

  18. OMagain

    William,

    to avoid an unpalatable conclusion – that morality, under atheism, is necessarily subjective in nature.

    And given that morality, under theism, is demonstrably subjective in nature you have achieved nothing. It’s a zero sum game.

  19. PatrickPatrick

    William J. Murray: UD welcomes legitimate doubt and legitimate differences of opinion with open arms.

    If that were said by anyone other than you, I would call it an out and out lie.

    Since you admit to believing whatever you wish independent of any evidence, I will only say that your statement is in flat contradiction to objective observation.

    If you ever decide to test your beliefs against reality, I suggest you visit the After the Bar Closes forum on the Panda’s Thumb and read some examples of the comments that resulted in bans. Legitimate doubt and differences of opinion are anathema to the censors of UD.

  20. Allan Miller

    For example, when William says that “FSCI/O can easily be calculated” I can be 100% certain that is an incorrect statement.

    And, indeed, if William asserts that he chooses what to believe, “I can be absolutely certain I exist” is not a ‘real’ belief, just one of those WJM-chose-it-because-it-appealed kind of things. I am aware of the existential absurdity. That’s why I said it.

  21. keithskeiths Post author

    davehooke,

    As far as logic and mathematics go, then there is certain knowledge to the extent that the axioms of the system are accepted.

    Accepted as absolutely certain. We must also be absolutely certain that our reasoning is correct.

    Neither of those is possible, so absolute certainty of any logical or mathematical conclusion is unjustified.

  22. keithskeiths Post author

    William,

    There are other statements on can be absolutely certain of, such as the LNC (there are no 4-sided triangles) and Royce’s Error (error exists), which are again statements about the world (what exists), regardless of what the world actually is – that is, if one isn’t being pathologically hyperskeptical.

    According to you, I’m being “pathologically hyperskeptical” when I claim that the probability of X isn’t 1.000…, it’s 0.999…9.

    An epsilon of 0.000…01 is pretty flimsy support for an accusation of “pathological hyperskepticism.”

  23. Lizzie

    Patrick: Legitimate doubt and differences of opinion are anathema to the censors of UD.

    The problem of course is that at UD, what counts as “legitimate” is rather circumscribed.

  24. keithskeiths Post author

    Lizzie,

    I think that you, William, kairosfocus, and StephenB are making the same mistake (though I hasten to add that you are erring with far more grace than the others. :))

    All of you acknowledge that human minds are fallible, yet you insist that there are at least some things of which we can be absolutely certain. Denying those things leads to absurdity; therefore, you argue, they must be absolutely, 100.0% certain.

    The problem is that if human minds are fallible, then our judgments of absurdity are also fallible. If you can’t be absolutely certain that the denial of a proposition is absurd, you can’t be absolutely certain of the proposition itself.

    This weakness is not specific to your argument. Any attempted justification of absolute certainty comes from someone’s fallible mind. It therefore cannot be absolutely certain.

  25. Lizzie

    I take your point, keiths (and I’m a little embarassed to have seemed to throw you under a bus!) but I’m trying to make a distinction that I’m still trying to figure out….

    I think there is a difference, somehow, between a provable statement (which a smart mathematician could prove with certainty, but I’m just not smart enough to be sure I haven’t made an error) and an empirical conclusion (and there’s a reason I’m an empirical scientist, not a mathematician!)

    And nonsensical statements such as “I do not exist”.

    But maybe one of the mathematicians will weigh in. Or throw me under a bus.

  26. Kantian NaturalistKantian Naturalist

    I’d much rather continue the conversation here than at Uncommon Descent. I’ll boycott UD in response to the ban on keiths, which I consider completely unjustifiable. Not that they’ll miss me — it’s quite clear to me that my contributions to those conversations are not treated as valuable.

    On the question of “certainty”: well, for one thing, I treat “absolute certainty” as redundant, so I’ll just talk about “certainty”. And “certainty” itself ambiguous, because it can refer to the logical status of necessity or to the psychological state of not doubting. I think that Descartes conflated them, and very few philosophers have called him out on it. (Spinoza did, in the Ethics, but Spinoza is hardly read any more, which is a terrible shame.)

    Insofar as I can really wrap my head around the idea of “certainty” at all, I prefer to think about it in terms of phenomenological disclosure: that is, what appears to us, as it appears to us, when we describe what it is that we experience. (C. I. Lewis’ “apprehension of the immediate” strikes me as an attempt to turn phenomenology into epistemology, and that’s a really problematic move — I’ll explain why when I’ve finished figuring it out myself.)

    But the phenomenological truths, the truths of disclosure are in a different ‘class’, so to speak, than the empirical truths about the world that comprise ordinary knowledge and scientific knowledge. Fallibilism about empirical truths doesn’t entail fallibilism about logical truths or phenomenological truths. Logical truths are grounded in the norms of rational discourse, including the norms of rational discourse about objects. Once we’re committed to talking about objects, the law of non-contradiction falls out as a meta-linguistic explication of the norms of discourse about objects. (This is why, in philosophical systems that reject the law of non-contradiction, such as the four-fold logic of Buddhism, there is no commitment to objects in the recognizable, Western sense of the term.)

    It’s often claimed, by “us naturalists,” that the human mind is not completely reliable. But I wonder what that really means, and what it commits us to or entails. The human mind, like the mind of any animal, is roughly reliable when it comes to detecting motivationally salient environmental stimuli and coordinating behavior with those stimuli. Skilled, embodied coping with the environment is not, of course, accurate copying of the world (the Mind as the Mirror of Nature, as Rorty nicely put it). But the absence of the latter does nothing to impugn the former, either.

    When it comes to logical truths, things are a bit different. Here I would like to say that logical truths are not Out There in Platonic heaven, or whatever, but are just implicit in the norms of rational discourse. I’m not sure we could fail to correctly grasp what those norms are, since the norms determine what counts as correct or incorrect. Faced with a pluralism of logics, I do not think we have any meta-logical criteria for adjudicating between them. So we may be stuck with logical pluralism, and ontological pluralism, and ethical pluralism.

  27. keithskeiths Post author

    Lizzie,

    …I’m a little embarassed to have seemed to throw you under a bus!

    Oh, don’t worry about that. I’m already covered in tread marks. That’s part of the fun of Internet debates!

    I think there is a difference, somehow, between a provable statement (which a smart mathematician could prove with certainty, but I’m just not smart enough to be sure I haven’t made an error) and an empirical conclusion (and there’s a reason I’m an empirical scientist, not a mathematician!)

    There is a difference, and it’s an important one. Mathematical claims can be adjudicated without reference to the external world, but empirical claims cannot. Philosophers use the terms “analytic” and “synthetic”, respectively, for these two types of claims.

    I affirm the distinction, and I agree that the former are “more certain” than the latter. However, I deny that either category contains truths of which we can be absolutely certain. We’re fallible, and it is always possible that we are mistaken.

  28. Kantian NaturalistKantian Naturalist

    keiths:
    .Mathematical claims can be adjudicated without reference to the external world, but empirical claims cannot.Philosophers use the terms “analytic” and “synthetic”, respectively, for these two types of claims.

    I affirm the distinction, and I agree that the former are “more certain” than the latter.However, I deny that either category contains truths of which we can be absolutely certain.We’re fallible, and it is always possible that we are mistaken.

    I like what you’re trying to say here but I think the phrasing could be refined a bit.

    For one thing, the analytic/synthetic distinction needs to be supplemented with the a priori/a posteriori distinction. And whether these distinctions completely overlap, or if there is a “synthetic a priori“, is itself a hotly debated question.

    When Kant defines the a priori, he says it is characterized by the “marks” (Merkmale) of universality and necessity. He doesn’t think that the a priori can be revised. So when C. I. Lewis, Carnap, and Sellars try to turn Kant’s a priori in a pragmatist direction, I have trouble seeing just what happens to the very distinction between a priori and a posteriori judgments — though I suspect that Sellars has the best view, out of the three of them.

    Basically, he construes a priori judgments as the constitutive rules (I would say norms) of a conceptual framework — the rules that make it possible to use that framework at all — and a posteriori judgments are the specific moves made within that framework. So Sellars would be happy to say that even the frameworks themselves are historically contingent and open to revision. In that sense, then, there isn’t any a priori in the strict, Kantian sense.

    At one point Sellars says that “the essence of scientific wisdom lies in being tentative about what we take to be extra-logically necessary”. I would add to that, in light of fairly recent developments in formal logic, that not even logical necessity is entirely immune to revision.

  29. davehooke

    keiths:
    davehooke,

    Accepted as absolutely certain. We must also be absolutely certain that our reasoning is correct.

    Neither of those is possible, so absolute certainty of any logical or mathematical conclusion is unjustified.

    Second point conceded, but I don’t know what it means to accept a certain geometry as “absolutely certain” when it is just one of many possible geometries. Same with logic.

    Axioms don’t even have to apply to anything in the world.

  30. keithskeiths Post author

    Kantian Naturalist:

    I’d much rather continue the conversation here than at Uncommon Descent. I’ll boycott UD in response to the ban on keiths, which I consider completely unjustifiable. Not that they’ll miss me — it’s quite clear to me that my contributions to those conversations are not treated as valuable.

    kairosfocus rationalizes the banning:

    KS knew the reasonable limits at UD, and he deliberately went over them, to falsely smear both the one he accused and the site that would not tolerate defamation as an alleged expression of freedom of speech.

    After all, a true but unflattering statement about an ID supporter is “defamation”, while false and hysterical statements about ID critics are just fine. UD is littered with them, many from KF himself.

  31. keithskeiths Post author

    davehooke,

    Second point conceded, but I don’t know what it means to accept a certain geometry as “absolutely certain” when it is just one of many possible geometries. Same with logic.

    I addressed that in a comment at UD:

    To ask whether our logic is correct is meaningless only if you take logic to be a free-floating set of rules that can neither be right nor wrong.

    Of course that is not true, except possibly in some arcane branches of mathematical logic. For most of us, logic is a tool for making inferences about the world. Some rules of inference are better than others, because some rules are truth-preserving, whereas others are not.

    I gave an example to KN earlier in the thread:

    For example, suppose I make the following fallacious inference:

    1. If X is a bird, then X has wings.
    2. A bat has wings.
    3. Therefore a bat is a bird.

    The average person immediately recognizes that inference as fallacious not because it violates the rules of logic, but because the conclusion is absurd. Having recognized the conclusion as absurd, he then goes back and looks for the logical error.

    Also, remember that the rules of logic were not handed down from On High. They were written by humans who were attempting to codify the process of inference. (Boole’s magnum opus was titled The Laws of Thought, after all.)

    They would write a candidate rule and then test it against experience to see if it worked.

    This has to be true. If candidate rules weren’t tested against reality, then there would have been no reason to favor one (good) system of logic over another (bad) one. We would have ended up with bogus systems of logic that weren’t truth-preserving.

    We could define a logic in which the bird/bat inference was allowed. However, it wouldn’t be a very useful logic, and I would assert that it would in fact be incorrect, in the sense that it would produce false conclusions from true premises.

    davehooke:

    Axioms don’t even have to apply to anything in the world.

    True, and in that case it is meaningless to talk about whether a conclusion is true or false. However, it’s still meaningful to claim that the conclusion either does or does not follow from the axioms, and to ask whether we can be absolutely certain of that.

    I say no, of course.

  32. keithskeiths Post author

    KN,

    On the question of “certainty”: well, for one thing, I treat “absolute certainty” as redundant, so I’ll just talk about “certainty”.

    Unfortunately, people often talk about degrees of certainty. That is, they don’t treat certainty as a binary concept. That’s why I’ve been using qualifiers such as “absolute” or “with a probability of 100.0%” in this discussion.

    And “certainty” itself ambiguous, because it can refer to the logical status of necessity or to the psychological state of not doubting.

    From earlier in the thread:

    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.

    KN:

    But the phenomenological truths, the truths of disclosure are in a different ‘class’, so to speak, than the empirical truths about the world that comprise ordinary knowledge and scientific knowledge. Fallibilism about empirical truths doesn’t entail fallibilism about logical truths or phenomenological truths.

    Agreed. But we already know that we are fallible about both categories. People do make logical errors, after all.

    It’s often claimed, by “us naturalists,” that the human mind is not completely reliable. But I wonder what that really means, and what it commits us to or entails. The human mind, like the mind of any animal, is roughly reliable when it comes to detecting motivationally salient environmental stimuli and coordinating behavior with those stimuli.

    But “rough reliability” can’t by itself underwrite absolute certainty.

    When it comes to logical truths, things are a bit different. Here I would like to say that logical truths are not Out There in Platonic heaven, or whatever, but are just implicit in the norms of rational discourse. I’m not sure we could fail to correctly grasp what those norms are, since the norms determine what counts as correct or incorrect. Faced with a pluralism of logics, I do not think we have any meta-logical criteria for adjudicating between them.

    I think we do. See this comment.

    At one point Sellars says that “the essence of scientific wisdom lies in being tentative about what we take to be extra-logically necessary”. I would add to that, in light of fairly recent developments in formal logic, that not even logical necessity is entirely immune to revision.

    As long as reasoning and perception are even potentially incorrect, absolute certainty is unjustified. I’ve argued that even God, if he exists, cannot attain absolute certainty from within his own cognitive framework.

  33. Lizzie

    Kantian Naturalist: When it comes to logical truths, things are a bit different. Here I would like to say that logical truths are not Out There in Platonic heaven, or whatever, but are just implicit in the norms of rational discourse. I’m not sure we could fail to correctly grasp what those norms are, since the norms determine what counts as correct or incorrect. Faced with a pluralism of logics, I do not think we have any meta-logical criteria for adjudicating between them. So we may be stuck with logical pluralism, and ontological pluralism, and ethical pluralism.

    I like this. I will have to chew on it for a bit, but it looks as though it makes sense to me!

  34. Allan Miller

    “The site that would not tolerate defamation?” Damn. Cornflakes all over the screen. I’ll get a cloth.

  35. keithskeiths Post author

    KN,

    I’m not sure we could fail to correctly grasp what those norms are, since the norms determine what counts as correct or incorrect.

    It happens all the time. For example, someone who makes the bat/bird mistake has failed to correctly grasp what the norms are. She recognizes her error by the fact that her conclusion is untrue, not by the fact that her reasoning deviates from the norms.

    Faced with a pluralism of logics, I do not think we have any meta-logical criteria for adjudicating between them.

    Sure we do. We prefer logics that are truth-preserving, as the bat/bird example shows. We prefer logics that are useful, which is why single-valued logic has very few takers :). We want logical systems that are consistent and complete, which is why Gödel’s result was such a bombshell.

    But all of this is moot. Regardless of how you select your rules of logic, it is always possible for you to apply them incorrectly. Error is always a possibility, and absolute certainty is therefore unjustified.

  36. keithskeiths Post author

    A few days ago, Richardthughes found the perfect movie clip for this topic.

    Astronaut uses Cartesian reasoning to disarm a smart bomb

    Kantian Naturalist even uses that clip when teaching Descartes.

    I agree with the point of the clip, insofar as it shows that our knowledge of the external world cannot be absolutely certain. I just take things a step further by noting that even internal truths cannot be regarded as absolutely certain. Our minds are fallible, and even seemingly “undeniable”, “intuitively obvious” or “self-evident” beliefs might therefore be mistaken.

  37. keithskeiths Post author

    Some choice quotes on certainty:

    Doubt is not a pleasant condition, but certainty is absurd.
    -Voltaire

    The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice.
    -Bertrand Russell

    The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers.
    -Erich Fromm

    Inquiry is fatal to certainty.
    -Will Durant

    Science has proof without any certainty. Creationists have certainty without any proof.
    -Ashley Montagu

    It’s not so much religion per se, it’s false certainty that worries me, and religion just has more than its fair share of false certainty or dogmatism. I’m really concerned when I see people pretending to know things they clearly cannot know.
    -Sam Harris

    Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.
    -Bertrand Russell

  38. keithskeiths Post author

    And:

    Moral certainty, clear standards, and a commitment to spiritual ideals will set you apart in a world that searches for meaning.
    -Mitt Romney

    😀

  39. Larryest

    I ‘believe’ (because when you get down to it this is a pure philosophy question) that the only absolute certainty possible is that absolute certainty much like the concept of perfection is an abstract concept that can never be truly fulfilled without absolute infinite and infallible knowledge of everything that does and does not exist. Concepts like these are why we create deities to fulfill our insane and ill-conceived imperfect mental machinations. I noticed that in a number of comments people beliving in absolute certainty always have refferential conditions, since i can alter any number of these conditions, these proofs only serve to prove my point.

  40. keithskeiths Post author

    Announcement:
    The “Rules of Right Reason” have been promoted to the “First Rules of Right Reason“, courtesy of StephenB.

    Stephen’s post includes this bizarre bit of illogic:

    One can say, “If A, then B”, only if everything except B is understood to be an impossible consequence of A.

    Looks like they skipped the First Rules of Right Reason at StephenB’s school.

    Nice own goal, however. How embarrassing for Stephen.

  41. keithskeiths Post author

    More from StephenB’s post:

    The city of Los Angeles simply cannot have more people than the entire state of California. Any such claim would violate one of the first principles of right reason: A finite whole can never be less than any one of its parts. Drawing on that same principle, I can be equally certain that a man’s head cannot displace more water than his entire body or that our sun cannot weigh more than the solar system of which it is a part.

    And the electric charge of a baseball cannot possibly be less than the charge of all of its protons taken together. (As kairosfocus likes to say, ‘oopsie!’)

    Evidence does not inform the rules of right reason; the rules of right reason inform evidence. That is because self-evident truths, the starting point from which all rational inquiry begins, provide the means by which all other truth claims, scientific or otherwise, must be evaluated.

    Yeah, so ignore the charge of those protons. The First Rules of Right Reason take precedence. They inform science, rather than vice-versa.

    There is no reason, for example, to conduct an empirical investigation to negate or affirm the hypothesis that a gold bar could come from a gold sliver, or that a sand castle could come from a single grain.

    Apparently the first law of thermodynamics is a “self-evident truth”, or a “First Principle of Right Reason”. Those silly scientists with their silly careful measurements. All they needed to do was to ask Stephen!

    Thank you for your post, Stephen. It is a perfect illustration of why absolute certainty — particularly in the hands of sloppy thinkers like you — is a dreadful mistake.

  42. Kantian NaturalistKantian Naturalist

    In a day or two, I’ll put up a TSZ post about how pragmatism is a safe, comfortable via media between absolutism and nihilism. I hope it will spark some good discussions.

  43. Lizzie

    cross-posted at UD

    Interesting post Stephen, but like Neil, I also have a couple of issues:

    A finite whole can never be less than any one of its parts.

    Depends on whether there’s a change in units! That’s not just a nitpick: I think the relationship between wholes and parts is extremely interesting, and they have non comparable properties. In fact very few things are sums of parts consisting of parts that are also sums of the same kinds of parts. Most things are much more interesting: a state consists of both cities and non-cities, and the properties of a state are different to the properties of either cities or non-cities. And of course a person has very different properties to any of her parts, as do her parts (which is why I don’t call myself a “reductionist).

    And it also depends on what you mean by “parts” – when you split an atom, or fuse two, you end up with less than the sum of the parts you started with. Sure, you get a lot of energy as well, but the ontology starts to get a bit wonky once you start converting between matter and energy.

  44. keithskeiths Post author

    The meta-argument against absolute certainty, inspired by StephenB’s error-ridden post at UD:

    As a fallible human, you can’t be absolutely certain about whether absolute certainty is justified in a given case (just look at StephenB’s post for several existence proofs).

    If you feel absolutely certain of something that you shouldn’t be absolutely certain of, the consequences can be dire: you won’t question yourself, because you feel absolutely certain, and you may therefore never discover your mistake.

    On the other hand, if you fail to be absolutely certain of something that warrants it (if there even is such a thing), then what have you lost? You’ll just think about it some more.

    Yet KF thinks it’s the end of the world, and StephenB echoes him:

    It isn’t just the integrity of science that is at stake. Our ability to engage in any kind of rational discourse depends on it.

    Get a grip, guys. The difference between a probability of 1.0 and 0.9…99 is only 0.0…01.

    The sky is not falling.

  45. Alan FoxAlan Fox

    Lizzie: the ontology starts to get a bit wonky once you start converting between matter and energy.

    Stephen seems stuck in classical concepts and the human scale. At the very small and the rather large, classical concepts don’t appear to have much use.

    Had I a transparent plastic sack large enough, could I put Jupiter in it and claim everything inside was Jupiter and everything outside not Jupiter? Photons would freely pass though and the distortion of space-time would extend beyond the sack.

    At the scale of fundamental particles, we can’t tell one proton from another, tag it or know whether it is new-born or as old as the universe.

    Pragmatists unite!

    ETA: It occurs to me that mentally putting Los Angeles in a plastic sack is equally futile

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