Absence of evidence IS evidence of absence

Oh come on Crash. Of course, we can argue about inconclusive positions. If there is a lot of evidence for both sides an really interesting discussion of it all may be a way to arrive at some sort of conclusion.It may also be away to find that we simply don't have enough evidence to get both sides to arrive at the same tentative conclusion but maybe will figure out what is needed to pick between them.If there is very little evidence then there isn't much good having an argument. That is, if the proposition is VERY inconclusive. As DNA points out if it is completely "conclusive" then there is also not much room for argument. (Though that hasn't stopped the YEC'ers has it? )As for the life as we know it thing I'd say it is in the too little information available to do more than arrive at a "We don't know, let's wait and see" position.I think you both are approximately are at that position but neither of you seem to be able to keep from making a step (with no evidence) to where you'd like the answer to be.

Well, yeah, we're doing it in the other thread.But the one thing you can't do with an inconclusive position is say "I'm right, prove me wrong." That's exactly what DNA continues to do. I dunno. I'm at a position where I say "why bother to assume that the universe is fine-tuned for life?" DNA appears to be at a position where he says "The universe is fine-tuned for life; prove me wrong."His position sounds like he's a lot more certain about it than mine. It's that tone that I object to, especially in the face of his repeated agreements that there's no evidence for or against fine-tuning.

Ok, I'll let DNA clarify that for us. He can do that in the other thread and that will (or won't) settle it.

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I don't agree with your logic.

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(1) Position X's status being inconclusive
and
(2) There being no way to argue for position X
are not the same thing.

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In fact, if something IS CONCLUSIVE, then how could one legitimately argue about it?

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In fact, it is basically only the things that ARE INCONCLUSIVE that can be argued for or against.

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But in fact (2) is exactly what (1) means.

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Out of curiosity, do you even try to remember what was said a few messages back before blurting out your first thoughts? Please read this again.

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Another that comes quickly to mind is the dispute over whale evolution: have whales descended from a mesonychian ancestor or an artiodactyl? Back in 1999 (if not still) both sides claimed to have enough evidence to show their position correct and the opposing side's wrong: note that at most, only one of those opposing groups of scientists can be correct: the other team must be wrong.

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The ancestry of whales was still in question — it had not been settled — it was inconclusive - yet the two sides still argued for their own position. How could that possibly be true if what you stated was also true? It couldn’t be...yet it is.

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When something is inconclusive, it means that one is unable to reach a conclusion about it. How could you argue, therefore, if you cannot conclude?

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More words games < sigh >One needs to use only 1 counterexample to successfully counter the opponent’s position...What about whale evolution? Each side drew its own conclusion, yet the matter clearly wasn’t settled (at least one side had to be wrong, but which one?). So both side’s evidence was inconclusive, yet both sides drew a conclusion, and both sides argued for their position.PS: Ever hear of the term TENTATIVE conclusion? It's a conclusion that is not conclusive; some uncertainty still exists and the debate is not ended. So it is possible for something to be inconclusive and yet one can draw a conclusion about it.[This message has been edited by DNAunion, 11-14-2003]

It's an X that's not an X? Now who's playing word games?Kudos for, once again, avoiding the core issue. Is there any point in talking to you?Besides, as you well know, all conclusions of science are tentative, so your distinction is either erroneous or meaningless.[This message has been edited by crashfrog, 11-15-2003]

In my feeble way of following this topic, I find myself falling to DNA's side of the arguement, in both the admin and non-admin modes. Yes, I have a biased perspective.I suggest all calm down, regroup and/or reorganize, and try to raise the discussion quality of this topic.And Ned - I very much think you can post here in the admin-mode, even though this forum isn't one that you have designated moderator status. That "Admin" prefix does seem to have some enhanced impact, when you're trying to inject some guidence.Adminnemooseus------------------
Comments on moderation procedures? - Go to
Change in Moderation?
or
too fast closure of threads

What, that you can adopt a position of ignorance, and use it to draw conclusions?The problem with this whole business is that wholesale acceptance of the absence of evidence as evidence is tantamount to turning ignorance into evidence. And there's plenty of ignorance - the ultimate renewable resource - so basically you can use it to prove any statement you like. Observe: DNA has used it to suggest that the universe is fine-tuned. I'll use it to prove that it's not.If the universe is "fine-tuned", that means that the fundamental constants of the universe must be "set" to specificvalues within an arbitrary range so as to allow for the presence of life. That would mean that universes set to different values would be devoid of life. If the range of values is large and our own universe is fine-tuned, then we should see lifeless universes all over the place.Instead what we see is that all observable universes contain life. There is no universe set to values that do not allow for life. Therefore we can conclude (tentatively) that the fundamental constants cannot be set in a way that does not allow for life - they can only take on values that allow for life. Therefore an argument of fine-tuning is flawed because the evidence clearly shows that it's physically impossible for a universe not to contain life, as 100% of universes contain life.See, it's just stupid. Once you accept ignorance as evidence you can prove any stupid thing you like, including contradictory positions. Clearly, as a method, it is flawed.[This message has been edited by crashfrog, 11-15-2003]

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[A tentative conclusion is] a conclusion that is not conclusive; ...

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It's an X that's not an X?

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Who said that? Not me.

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Now who's playing word games?

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Same person as before...you.By saying "it's an X that's not an X" you are using X to represent both CONCLUSION and CONCLUSIVE. Besides the fact that one word is a noun and the other an adjective (which exposes one error in your line of reasoning), the two are NOT identical: thus a second reason your equating X with both is flawed. Let me explain that second one a bit more.If what you imply were actually true, then all conclusions would necessarily have to be conclusive. It would necessarily follow that there would be no such thing as a tentative conclusion. Yet there is such a thing as a tentative conclusion, as even you admit. Consequently, your underlying logic in your counter must be flawed.

Crash you are bring the other thread into this one. This is more (or should be) of a theoretical thread to discuss the nature of evidence. If the idea of "absent evidence" being useful is clarified properly here then it's misuse can be prevented in other threads.In parts, at least, of the discussion here the absence of evidence is not simply "ignorance". It is a collection of null results from selected experiments. Enough of these, in my mind, may be considered a form of evidence, even useful evidence.In fact, a serious problem in research today (certainly in medicine) is that null results tend not to be published. These experiments didn't "find the keys". These results *are* evidence and the tendancy not to publish them results in misleading meta-studies.What you might want to sort out is what is required to make the absence of evidence into something useful. Clearly if no work is done what so ever (either because we haven't or can't do it - eg. we can't look at other universes yet) then the absence may be considered to be meaningless. However, there must be a point at which continuted absence starts to become meaningful.If it takes 100,000 "looks" to search the experimental space we only have proof of absense when we have looked at all 100,000. However, I am not going to be easily convinced that after 99,999 looks we don't have something that we can draw a pretty firm tentative conclusion on. If that is now meaningful how about 99,000?

Yes, and in a scientific context, all conclusions are tentative. So you're trying to draw a distinction that doesn't exist.

That's not an absence of evidence. That's evidence. What would you call it if we concluded that the thing is absent after searching one place in an expermental space of unknown size? You can't make conclusions from an absence unless you know how much of the whole that absence represents.Which is to say that I totally agree with you. But what you're saying is different than what DNA is saying.

I thought I was saying something similar (the same? ) as DNA in this thread. Perhaps he can clarify that. As for the other thread I'm not discussing that here. I would call that pretty poor reasoning. But there are gradiations possible here. We have commented a lot about how "tentative" science is.However, there are degrees of tentativeness. Let's face it when a theory has passed a century of tests (ToE) or predicted esoteric behaviours of the universe (general relativity) we take it as less tentative, a LOT less tentative. As. I think you, said elsewhere we get dogmatic. It is simply efficient to stop re-questioning things that have been gone over very toughly.Obviously a search of one sample in an unknown space would be pretty poor evidence to get very dogmatic on. But the point of this thread is that it *IS* evidence.

Nonetheless as the other thread was the context that spawned this thread, it's valid to bring it up. The title of this thread begs the question "evidence for what?" and the answer to that is what DNA was trying to do in the other thread. Well, it's what DNA was trying to do in the other thread.If you don't feel that's an appropriate subject for this thread, then I guess I don't have anything else to talk about.

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I thought I was saying something similar (the same? ) as DNA in this thread.

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So did I. But I guess we are both wrong on what we believe we think.

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Obviously a search of one sample in an unknown space would be pretty poor evidence to get very dogmatic on. But the point of this thread is that it *IS* evidence.

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Hmmm, that matches what I've said...well, as far as I can tell...I guess I'll have to ask Crashfrog to tell me what I think before I go saying what I think! :-)

Then I guess you can carry it back to the other thread. We seem to have agreed that absence of evidence is evidence of absence but only under some not so clearly spelled out conditions. Sometimes it is very weak evidence and sometimes it is rather strong. We seem to have agreed on that too.