Thursday, October 16, 2008

Just because I can't prove it

Just because I can't prove it, doesn't mean it's not true.

Or so goes the thrust of Tit For Tat's comment on DagoodS's excellent blog.

There are a lot of things wrong with this attitude.

First of all, as DagoodS notes, we can evaluate many claims — such as Tit For Tat's "par 4 hole-in-one" example — by appeal to circumstantial evidence. The disanalogy to claims about God is sharp: we lack even circumstantial evidence for claims about God.

Second, we have to look more deeply at "can't"; this is an equivocal term, because it can refer either to practical difficulty or theoretical impossibility, which are two very different issues.

The notion of time symmetry (reversibility) is extremely important: That physical laws are time-symmetric is another way of describing the conservation of mass-energy. This means that, in theory, we can make actual observations; if those observations are sufficiently accurate, we can "wind back the clock" using the time-symmetric laws of physics, and determine precisely what happened in the past. Even issues regarding the role of the observer in quantum mechanics do not prevent this sort of observation and retrodiction. Of course the practical difficulties of making such specific observations are overwhelming. But there is nothing that prohibits us in principle from doing so.

Again, the disanalogy to claims about God is sharp. The problems about knowing or proving claims about God are not practical, it's not like God is hiding behind my couch, or even around some distant star. The problems are theoretical: You cannot in principle know anything about a God who makes no observable difference in the world, at least not by empirical, scientific methods.

But the philosophical issues are most severe. What precisely do we mean by true but unprovable propositions?

For example, empirical science might not be the last word in epistemology, but if we could somehow know things about God by some alternative methodology, then the objection about the unprovability of true propositions would be rendered moot. Simply proposing an alternative methodology does not inform us as to the truth of propositions that cannot be resolved by any methodology. The claim is not, "Just because I can't scientifically prove it..." the claim is that "Just because I can't prove it at all..." The first version simply raises the question, "If you can't prove it scientifically, how can you prove it?" The second version raises more profound philosophical questions.

We intuitively believe that there are true propositions we don't know are true, therefore there propositions are true or false independent of our knowledge of their truth or falsity. But again, we must be very precise, because "independent of" has the same equivocal meaning as "can't" above. Do we mean independent of practical considerations, or do we mean independent of principled considerations, considerations that follow from the theoretical limits of our epistemology? None of our present knowledge was unavailable in principle to anyone, ever, and what we think we can't know we think we can't know because of the practical problems acquiring that knowledge. Under scientific methodology, ignorance is always a practical problem, not a theoretical problem. And the clear implication is that a statement that can't be be known in principle is not truth-apt.

Under a scientific methodology, truth is metaphysically subordinate to knowledge. To call a statement "true" is to just say that we know it's true, and to call a statement truth-apt is to know ("meta-know") that, in principle, we could know that it's true.

The problem with unknowable-in-principle "truth" is that by definition, because the truth is unknowable in principle, we cannot agree on its actual truth. By definition, no contradiction is entailed by believing the statement is true, nor is any contradiction entailed by believing the statement is false. Just entertaining the idea of unknowable-in-principle "truth" is to deny the essential semantic property of what we mean by "truth": true for everyone, always. Unknowable-in-principle "truth" is impossible to distinguish from opinion.

Of course, there's nothing wrong per se with opinions, desires, preferences, values, and other purely subjective entities. Having and acting on opinions is part of what it means to be human; we are not mere "knowing machines", concerned exclusively with knowing the truth.

But confusing our subjective preferences with actual objective truth is very dangerous, because we have very different ethical beliefs about truth than we have about opinions. "True" means "true for everyone"; if we confuse our opinions with truth, we must then conclude that someone holding the opposite opinion is mistaken, often dangerously so, in just the same sense that a person who believes that it is safe to drive while intoxicated is dangerously mistaken.

23 comments:

  1. True" means "true for everyone"; if we confuse our opinions with truth, we must then conclude that someone holding the opposite opinion is mistaken, often dangerously so, in just the same sense that a person who believes that it is safe to drive while intoxicated is dangerously mistaken.

    What if the culture you grow up in decides drinking and driving is ok?. Does your "truth" then change. What if culture decides its ok to cut the head off a Barefoot Bum and throw it to the Lions, would that "truth" not be right?.

    ReplyDelete
  2. Tit for Tat: When did I ever suggest that I was a cultural relativist? Everyone means everyone, not just the members of one culture at one particular time.

    I didn't talk about whether drunk driving was "OK", I talked about whether or not it was safe, i.e. posed minimal risk of harm to one's self or others. That is a factual issue.

    The overall theme of my moral philosophy is that objective moral propositions are not truth-apt. Nothing at all -- not individual preference, culture, law -- makes moral propositions objectively true in the same sense that "The Earth is (more-or-less) spherical" is objectively true.

    ReplyDelete
  3. Larry
    "I didn't talk about whether drunk driving was "OK", I talked about whether or not it was safe, i.e. posed minimal risk of harm to one's self or others. That is a factual issue"

    What if the culture isnt concerned about safety? In fact, what if another Culture deemed being hurt while drunk driving a virtue? Your disagreement seems to be based on what your idea of what a "truth" is.

    ReplyDelete
  4. T4T: What if the culture isnt concerned about safety? In fact, what if another Culture deemed being hurt while drunk driving a virtue?

    Then I expect there would be a lot of people driving drunk in such a culture. What's your point?

    Your disagreement seems to be based on what your idea of what a "truth" is.

    My disagreement with what? There are two assertions: Drunk driving is not safe, which is true; and drunk driving is bad (presumably because it is unsafe) which is not truth-apt: it is neither true nor false.

    It happens to be the case in our society that we are of the opinion that drunk driving is bad, and therefore we have made it illegal.

    I'm not talking at all about ethics in this post, I'm talking about truth, accurate ideas about the real world, not how we manage our

    ReplyDelete
  5. I'm not talking at all about ethics in this post, I'm talking about truth, accurate ideas about the real world, not how we manage our ethics.

    ReplyDelete
  6. Ok

    My question is, is truth only something that we can prove or disprove? In other words, if I have a "true" experience but cannot duplicate it or prove it to anyone, does that make me a Liar?

    ReplyDelete
  7. "There are two assertions: Drunk driving is not safe, which is true;"

    By the way, drunk driving is only not safe if the point of driving is to be safe. Again that is only based on what our culture dictates.

    ReplyDelete
  8. My question is, is truth only something that we can prove or disprove?

    Did you read the post? "And the clear implication is that a statement that can't be be known in principle is not truth-apt."

    By the way, drunk driving is only not safe if the point of driving is to be safe.

    Seriously: is English your second language? You seem to be having trouble with simple declarative sentences.

    It is objectively true that drunk driving is not safe, which has nothing to do with what the "point" of driving is or is not.

    Whether or not one condemns drunk driving because it is unsafe does depend on his opinion as to the the point of driving.

    ReplyDelete
  9. T4T:"if I have a "true" experience but cannot duplicate it or prove it to anyone, does that make me a Liar?"

    There is a difference between objective truth and and individual's assertion of what truth is.

    What we say can, and often does, reflect the objective truth but the truthfulness isn't affected by the fervor with which it is reported.

    If the 'truthful' item or event you report seems fantastic or unlikely, as well as being unreproducable and unverifiable, then many people will believe you to be a liar.

    ReplyDelete
  10. Just entertaining the idea of unknowable-in-principle "truth" is to deny the essential semantic property of what we mean by "truth": true for everyone, always.

    Gödel would disagree with you there. The fact that we can't identify the true-but-unknowable doesn't make then any less true, although it does make trying to identify them a little ridiculous.

    ReplyDelete
  11. Gödel would disagree with you there.

    Indeed. And I would disagree with Gödel. First of all, since I'm a materialist, I have profound doubts about the inherent truthfulness of mathematics, as opposed to its value in precisely stating truths about the real world.

    Second, Gödel casts more doubt on the law of the excluded middle than he does on the truthfulness of mathematics: his theorem is about what's not provable, and it's possible to prove any particular Gödel statement true in a higher-level formulation.

    Third, I've heard it said (although I'm no mathematician) that Gödel's theorems apply only to finite mathematical proofs. If you're going to have an infinity of natural numbers, it seems inconsistent to balk at other infinities as a matter of deep principle.

    ReplyDelete
  12. Dude, "disanalogy" is a fucking horrible word. I know it's old, but damn, it sucks dick.

    ReplyDelete
  13. see, Muslims (all religious persons, i am just telling about what i know), they call Islam Al Haqq and in Urdu of course haq means truth. What is truth, what we believe to be true and may or may not be or what is most certainly the case.
    See, how can i prove there is no Allah? I can't.
    But i can add up all the millions of childish mistakes in me (ex) religion-or in Christianity to make a logical deduction that if the truth that is true only in the heads of me family and me community has so many objective flaws and holes in it, as a comprehensive statement of TRUTH, me religion must be lies, or, true only to those who believe it, which is not a good enough standard of truth, it's just like a opinion, the only true aspect of it are the chemical enzymes that constitute the 'thought' of a false truth. This is what i think now.
    Truth can't be willed into existence, u can't think there is life on Venus with angelic beings with long white hair and paradise of rivers and write tales and holy books about it and across countless generations sincerely believe in if- after Venera mission going there and photographing it as a toxic hell, of course u can if u want, but that's faith, faith and truth are totally different, and faith only survives cos we can't measure every truth and people are so stubborn-stupid-backward to acknolwedge that thru inference, on all available evidence, theire so called truth is just a illusion, part of a belief system, independent of reality.
    Real pity all these religious leaders didn't place heaven on Mars, or Allah's throne on the moon, then we could have debunked the hole thing in black and white.
    That's how literal u got to be with people who willfully confuse faith and truth, playing on the fact that we can't (yet) measure everything, even though a basic and conscious understanding of facts like evolution, big bang calculations, social anthropology etc make the case perfectly clear leaving the only requirement as a little objectivity-reason-common sense, which apparently seems too much for millions of people, who,no doubt, see their religion as 'emotionally true', whatever the actual truth really is.

    ReplyDelete
  14. By the way, drunk driving is only not safe if the point of driving is to be safe. Again that is only based on what our culture dictates.

    Good grief! The point of driving is to get somewhere. If you don't drive safely, your chances of getting to where you're going become greatly diminished.

    ReplyDelete
  15. The "point" of driving is a side issue. Even if the point of driving were precisely to be unsafe, it would still be true that driving drunk was less safe than driving sober... but of course then it would be better to drive drunk.

    The factual truth doesn't change according to ethical or preferential status.

    ReplyDelete
  16. What if the culture you grow up in decides drinking and driving is ok?.

    That was exactly the problem. Drunk driving was not treated as seriously decades ago as it is today. Just look at the original version of the movie "The Bad News Bears" made in 1976. There is a scene where Coach Buttermaker is driving his convertible while drinking beer, and the kids on his team are sitting without their seat belts on. I didn't see the remake, but I strongly doubt that you would see a movie made today that would feature a scene like that.

    Why the change of opinion? Because too many people saw their loved ones killed or permanently injured at the hands of drunk drivers. It was because, as Barefoot Bum wrote above, an issue of safety.

    ReplyDelete
  17. "The factual truth doesn't change according to ethical or preferential status."

    What if the truth is I just want to drive? Whether I drive safe or unsafe doesnt change the fact that Im driving.

    ReplyDelete
  18. T4T: Let's stop talking about driving, since the conversation (or at least your half of it) is degenerating into inanity.

    ReplyDelete
  19. Ok larry

    If you could please answer me this one question, without any nastiness if possible. If I look at the world and see a sense of design to it, or at a minimum a cohesiveness. And behind that it would seem there is a level of intelligence, is it not reasonable to assume that there could be some sort of creative force behind it? I mean is that not a logical option? oops I think thats more than one question lol.

    ReplyDelete
  20. If I look at the world and see a sense of design to it or at a minimum a cohesiveness.

    You need to be more precise about what you mean by "design", "a sense of design, and "cohesiveness".

    And which do you in fact see? Design? A sense of design? Cohesiveness? How do you see design?

    And behind that it would seem there is a level of intelligence...

    "Seem" is a word that relates to appearance; and what is behind is by definition not appearance. Are you saying that you have a vague intuition about what's behind a vague description of what you're observing?

    ... is it not reasonable to assume that there could be some sort of creative force behind it?

    Again, you're not using language precisely. What do you mean by "creative force"? And formally, assumptions are not really "reasonable" per se, as in following from a process of reasoning. Assumptions are the beginning of deduction, which is one component of reasoning.

    Let me rephrase your question more precisely:

    We observe in some natural things interesting similarities -- structure, "cohesiveness", fitness to usage, a degree of inherent teleology -- that we see in artificial things, things we ourselves plan and create. Does it then make sense to hypothesize that there might be an intelligence that has planned and created such natural things?

    And the answer is, "yes, of course." But saying it this way makes it clear that we're starting to create an hypothesis, which must then be formulated more precisely and falsifiably.

    This is an hypothesis that has been considered extensively, and found false. The similarities notwithstanding, there are too many dissimilarities.

    People have a tendency to be intellectually defensive, to speak broadly enough that they're not held in error. This tendency to broadness, though, is anathema to scientific thinking. Scientists want to speak specifically, so that really matters if their statement is not found false, even under careful investigation.

    The problem with your formulation is that, in a sense, naturalistic, non-teleological evolution fits the bill.

    If I predict that either Obama or McCain will win the Presidential election in a couple of weeks, I'm right, but so what? I haven't said anything specific.

    ReplyDelete
  21. Larry

    Im curious, when youre out for a pint with your friends or co workers, are you this precise with your speech. I mean, do you talk like this all the time??

    I think Obama actually said something thats relevant for me(here at least). This may be above my pay grade.

    ReplyDelete
  22. Pretty much, yes. Of course, I don't have a backspace key in ordinary conversation, but I do try to think through what I'm saying and speak in complete sentences.

    I don't think this stuff is "above your pay grade" though. It takes some effort to educate yourself to precise thinking and speaking, but I think most any person of normal intelligence (and my own IQ is entirely normal) can learn the habits.

    ReplyDelete

Please pick a handle or moniker for your comment. It's much easier to address someone by a name or pseudonym than simply "hey you". I have the option of requiring a "hard" identity, but I don't want to turn that on... yet.

With few exceptions, I will not respond or reply to anonymous comments, and I may delete them. I keep a copy of all comments; if you want the text of your comment to repost with something vaguely resembling an identity, email me.

No spam, pr0n, commercial advertising, insanity, lies, repetition or off-topic comments. Creationists, Global Warming deniers, anti-vaxers, Randians, and Libertarians are automatically presumed to be idiots; Christians and Muslims might get the benefit of the doubt, if I'm in a good mood.

See the Debate Flowchart for some basic rules.

Sourced factual corrections are always published and acknowledged.

I will respond or not respond to comments as the mood takes me. See my latest comment policy for details. I am not a pseudonomous-American: my real name is Larry.

Comments may be moderated from time to time. When I do moderate comments, anonymous comments are far more likely to be rejected.

I've already answered some typical comments.

I have jqMath enabled for the blog. If you have a dollar sign (\$) in your comment, put a \\ in front of it: \\\$, unless you want to include a formula in your comment.