Absence of evidence = evidence of absence?

[T'ai Chi]

Is absence of evidence the same as evidence of absence?

Some people here think it is, but others disagree.

Who is correct?

[ImpyTimpy]

Originally posted by T'ai Chi
Is absence of evidence the same as evidence of absence?

Some people here think it is, but others disagree.

Who is correct?

To say that if something lacks evidence, it does not exist is to commit a clear-cut logical fallacy.

To say lack of evidence of something suggests it may not be possible/it may not exist is to use common sense.

:p

[plindboe]

Ugh, this is a tough one. Evidence is not proof, so even though there is evidence for something, doesn't neccessarily make it true.

I would say that absence of evidence is evidence of absence, but weak evidence, and not conclusive evidence in any way.

If a murder investigation can come up with no evidence at all that the suspect is guilty, then this fact alone increases the chance that he is innocent, thereby it is a form of evidence.

[Yahweh]

I'm a little out in the dark as to how you find empirical evidence (much less proof) to demonstrate the non-existence of something...

[thaiboxerken]

Originally posted by Yahweh
I'm a little out in the dark as to how you find empirical evidence (much less proof) to demonstrate the non-existence of something...

I think, according to woo-wooism and Tai Chi, that you can't ever prove the non-existence of something. Therefore, according to them, everything may exist and every claim is worth investigating. Except for invisible, blue, intangible smurfs.. for some unknown reason.

[ImpyTimpy]

Originally posted by thaiboxerken


I think, according to woo-wooism and Tai Chi, that you can't ever prove the non-existence of something. Therefore, according to them, everything may exist and every claim is worth investigating. Except for invisible, blue, intangible smurfs.. for some unknown reason.

You know, you're actually sort of correct there. Of course, the possibility is that everything may exist. Science has this cool theory that states there may be lots of different universes around with very different laws and mathematical equations to describe them. I don't remember what is the name of it though (starts with a I think).

Whether these things are worth investigating or not is another idea.

:)

[Yahweh]

Originally posted by ImpyTimpy
You know, you're actually sort of correct there. Of course, the possibility is that everything may exist. Science has this cool theory that states there may be lots of different universes around with very different laws and mathematical equations to describe them. I don't remember what is the name of it though (starts with a I think).
String Theory.

(The one with 10 spatial dimensions, 1 temporal dimension, branes, and lots of fun exotic particles like s_particles...)

[Stereolab]

Originally posted by thaiboxerken


I think, according to woo-wooism and Tai Chi, that you can't ever prove the non-existence of something. Therefore, according to them, everything may exist and every claim is worth investigating. Except for invisible, blue, intangible smurfs.. for some unknown reason.

It's funny how completely clueless you are, and how you're totally oblivious to that fact.

If you were more intelligent, and more of a skeptic, you'd realize that you don't know nearly as much as you think you do.

[thaiboxerken]

It's funny how completely clueless you are, and how you're totally oblivious to that fact.

You mean.. I don't believe in the paranormal, so I must be clueless, right?

Absence of evidence IS evidence of absence.. it's not conclusive, but it's highly suggestive.


If you were more intelligent, and more of a skeptic, you'd realize that you don't know nearly as much as you think you do.

You really don't like me, do you?

[Nyarlathotep]

It is more complicated thatn a simple yes or no.

Put into a short form my answer boils down to: no it is not evidence of absence but that doesn't mean much of anything. In the absence of hard evidence,if one is going to speculateon the existance of something, one then has to look at other things, such as how likely the thing is to exist, whether its existance contradicts the laws of the universe as you know them, etc.

So if I claim that I have a Cousin Ruth, but you have never met her nor met anyone who has (i.e. you have no evidence that she exists) you can safely act on the assumption that she does since her existance isn't unlikely and is probably trivial. If I clalm that my Cousin Ruth can fly by flapping her arms, then it changes. Since youhave no evidence you can't say 100% that I am blowing smoke, but since someone flying by flapping their arms contradicts the laws of physics, it would not be wise to assume that I am telling the truth.

It's oversimplified, to be sure, but that is how I look at things.

[Flatworm]

Absence of evidence is not evidence of absence.

However, lack of disproof is not a sufficient condition for making an idea worthy of serious consideration.

[gentlehorse]

Originally posted by thaiboxerken
I think, according to woo-wooism and Tai Chi, that you can't ever prove the non-existence of something. Therefore, according to them, everything may exist and every claim is worth investigating.

Where did Tai Chi say that every claim is worth investigating? You wouldn't be putting words in another's mouth, would you Ken? Is this your idea of presenting, or laying the foundation for, a rational argument? Surely not--

Of course, this kind of response is in keeping with your MO. I don't know why I would expect anything different of you. My bad--

[Paul C. Anagnostopoulos]

Is absence of evidence the same as evidence of absence?
My, this is difficult. Are we talking about complete and utter absence of evidence? If so, that's pretty good evidence of absence. Either that, or the thing we're looking for exists, but leaves no evidence. In which case, . . . well, you know the drill.

~~ Paul

[69dodge]

Originally posted by T'ai Chi
Is absence of evidence the same as evidence of absence?Depends.

How easy would finding evidence of it be, if it were present?

How hard did you look for evidence of it, before giving up?

[T'ai Chi]

Originally posted by thaiboxerken

I think, according to woo-wooism and Tai Chi, that you can't ever prove the non-existence of something. Therefore, according to them, everything may exist and every claim is worth investigating. Except for invisible, blue, intangible smurfs.. for some unknown reason.

Yawn.

Universal negatives maybe (because you have to search all of time and space, and last time I checked, that was pretty hard), but not any other negatives.

[!Xx+-Rational-+xX!]

Anything that skeptics don't agree with should be considered impossible! This means there can never be evidence nomatter what woo-woos say! Or else science will be destroyed! We were put here with the elite mission by natural selection to put an end to quackery!

[Paladin]

If there is no evidence that a certain thing exists, we can assume that it exists for the purposes of hypothesis and experimentation, but if repeated experimentation and/or observation fails to show evidence that the thing exists, we can be fairly certain that it just ain't there.

One must be careful not to fall into the trap of thinking that because there is no evidence that something does not exist, that it might exist.

Personally, I've come to the conclusion that a lot of things just ain't there. I won't worry about them unless they turn up. In the meantime, I have far more important and very real things to deal with. For now, ESP and other nonsense is a waste of my valuable time.

[Upchurch]

Strictly speaking, no. Absence of evidence is a indicator of absence, but it is not absolute evidence of absence.

[ImpyTimpy]

Originally posted by Ohrryp
If there is no evidence that a certain thing exists, we can assume that it exists for the purposes of hypothesis and experimentation, but if repeated experimentation and/or observation fails to show evidence that the thing exists, we can be fairly certain that it just ain't there.

I have to respectfully disagree there with you. If anything, I believe it may also show us that perhaps our experimentation methods are incorrect. As long as something is plausible and we may have a benefit in discovering it's existence, we should keep looking for it. If our repeated experiments fail to discover it, it does not automatically mean what we look for doesn't exist, it could mean our experimentation method may be flawed.


One must be careful not to fall into the trap of thinking that because there is no evidence that something does not exist, that it might exist.

That's true and I think some believers try and use this argument to support their beliefs. It's a very irrational argument but relative irrationality of something hasn't stopped people from carrying on with it.


Personally, I've come to the conclusion that a lot of things just ain't there. I won't worry about them unless they turn up. In the meantime, I have far more important and very real things to deal with. For now, ESP and other nonsense is a waste of my valuable time.
I agree to an extent, that is I think we shouldn't abandon the possibility of these things existing, hence we've got people who try and research these things. However, just because something might exist doesn't mean it does. Still, what if it did? I believe that may be what drives these people to try and discover the paranormal and I see no problem with that. I do have a problem with unfounded beliefs though.

[espritch]

Absence of evidence is evidence of abscence. It may not, however, be conclusive evidence.

[T'ai Chi]

Originally posted by Ohrryp
If there is no evidence that a certain thing exists, we can assume that it exists for the purposes of hypothesis and experimentation, but if repeated experimentation and/or observation fails to show evidence that the thing exists, we can be fairly certain that it just ain't there.

So no extra-terrestrials exist?

Are you fairly certain?

[apoger]

T'ai Chi, after reading this thread and a bunch of your other posts it seems apparent that you are making the mistake of equating "evidence" with "absolute proof".

Evidence is always modified by a confidence level, and is never absolute.

[Walter Wayne]

Absence of evidence is evidence of absence when a search has been carried out that would almost certainly uncover evidence.Originally posted by Ohrryp
If there is no evidence that a certain thing exists, we can assume that it exists for the purposes of hypothesis and experimentation, but if repeated experimentation and/or observation fails to show evidence that the thing exists, we can be fairly certain that it just ain't there.

Originally posted by T'ai Chi
So no extra-terrestrials exist?

Are you fairly certain?In this case, while the existence of extra-terrestials would leave evidence (it is testable), we have not made a search that would be likely to uncover said evidence. So in this case, evidence of absence is evidence of an inability to carry out a reasonable experiment to test the hypothesis.

Walt

[Charlie in Dayton]

Originally posted by Flatworm
Absence of evidence is not evidence of absence.

However, lack of disproof is not a sufficient condition for making an idea worthy of serious consideration.

Flatworm, I've saved your quote in my archives (with appropriate credit). I'm going to cogitate on that statement awhile...I immediately found it to be profound, and worthy of deep consideration. Somehow, I feel there's the seeds of an essay there.

Excellent turn of phrase.

After suitable consideration, I nominated it for the December Language Award.

[Hazelip]

What evidence does is support the reasonableness of a conclusion. If there is sufficient evidence for something, then it is reasonable to conclude that the particular something does exist. If there is no evidence to support a claim, then it may be reasonable to conclude that the particular claim is false, or that the thing does not exist. But, not in every situation.

Go search Cartesian Logic (http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=cartesian+logic&btnG=Google+Search).

[Darat]

T'ai Chi - Just thinking this through.

There is no evidence that I shot JFK so I take it that it would be wrong for someone to say "There is no evidence that Darat shot JFK therefore Darat didn't shoot JFK"?

[LTC8K6]

Well "absence of evidence" means no evidence at all to me.

It seems to me that a reasonable person could take that as an absolute.

However, you can't say there is an "absence of evidence" in many situations, so the answer would vary.

If the "absence of evidence" is a certainty, if the evidence would be obvious and it just isn't there, then a reasonable person could conclude that that equals "evidence of absence".

Of course the "absence of evidence" can change tomorrow. :)

[pgwenthold]

Absense of evidence where evidence should be is evidence of absense.

For example, there is no evidence that there is an elephant in my office. If there were an elephant in my office, I should expect to find certain indicators, such as big piles of dung. The lack of dung is evidence that there is not an elephant in my office.

If you think of it in terms of a hypothesis, then it makes sense. Hypotheses lead to predictions. If those predictions are not borne out, then that is evidence against the hypothesis.

[Skeptical Greg]

I would say an absence of evidence is a clear indication of no evidence..

Evidence for what ?

[Zero]

Absence of evidence, whatever else it is, is not a licence to believe or promote any and every crackpot idea that comes along.

[RichardR]

Yes – if you have looked for that evidence and not found any.

However, it is not proof of absence.

[Paladin]

Originally posted by T'ai Chi
So no extra-terrestrials exist?

Are you fairly certain?
Yup. I'm fairly certain that no extra-terrestrials exist.

However, I accept the possibility that I could be mistaken.

[espritch]

So no extra-terrestrials exist?

Are you fairly certain?

Let me put it this way. I am fairly certain that no Martians exist. We've sent probes and there was a distinct lack of evidence found (at least in the classic little green man sense). In this case abscence of evidence is pretty good evidence of abscence. Or do you think maybe there are little green men on Mars?

Obviously, I can't make any assumption about extra-terrestrials beyond our solar system since we currently have no means to look for conclusive evidence. There is a difference between failure to find evidence and inability to look for it.

[!Xx+-Rational-+xX!]

Skeptics are always right and any evidence that threatens this is false!

[Yahweh]

T'ai Chi, your current avatar is a little distracting. Here is the same image, it rotates smoother, its only 6,319 bytes (avatars can be up to 7000 bytes).

This GIF is compiled from 21 individual frames, the framerate is ~.04 per second. That means the amount of time for the Yin Yang to make one revolution is ~every .84 seconds (actually, the transition between frames will be slower depending on the speed of your processor... on most computers, the image will appear to rotate a bit slower than once per .84 seconds).

[Jeff Corey]

Originally posted by Ohrryp
If there is no evidence that a certain thing exists, we can assume that it exists for the purposes of hypothesis and experimentation, but if repeated experimentation and/or observation fails to show evidence that the thing exists, we can be fairly certain that it just ain't there.

One must be careful not to fall into the trap of thinking that because there is no evidence that something does not exist, that it might exist.

Personally, I've come to the conclusion that a lot of things just ain't there. I won't worry about them unless they turn up. In the meantime, I have far more important and very real things to deal with. For now, ESP and other nonsense is a waste of my valuable time.
I fully agree, but I still have some time to waste investigating weird claims. Maybe even writing them up for Claus.
Maybe,

[CFLarsen]

Originally posted by Jeff Corey

I fully agree, but I still have some time to waste investigating weird claims. Maybe even writing them up for Claus.
Maybe,

I'll take that as being affirmative.

Deadline's the 28th, six-eyes.

[T'ai Chi]

Originally posted by Yahweh
T'ai Chi, your current avatar is a little distracting. Here is the same image, it rotates smoother, its only 6,319 bytes (avatars can be up to 7000 bytes).

This GIF is compiled from 21 individual frames, the framerate is ~.04 per second. That means the amount of time for the Yin Yang to make one revolution is ~every .84 seconds (actually, the transition between frames will be slower depending on the speed of your processor... on most computers, the image will appear to rotate a bit slower than once per .84 seconds).

Sweeet. Thanks Yahweh.

Now one question. How do I get that animated icon to be my new avatar? I do a 'Open image in new window' and I am getting some .php file :( instead of a .gif; probably something on my end.

[Craig]

You know, that slower yin-yang is strangely hypnotic to watch.

Incidentally, I've got the urge to send all of my money to Yahweh...

[Yahweh]

Originally posted by T'ai Chi
Sweeet. Thanks Yahweh.

Now one question. How do I get that animated icon to be my new avatar? I do a 'Open image in new window' and I am getting some .php file :( instead of a .gif; probably something on my end.

The reason you are getting a .php file is because this software stores binary files in a database. This isnt the same as storing it locally on a server. Because the binary information is stored in the database, the SRC attribute of the IMG tag has to link to a .php file rather than a GIF file. The PHP file is a script which reads the binary information from the database.

I've stored the image on a VillagePhotos.com server.

If you want to change your avatar, you can go to User Control Panel - Edit Avatar (http://www.randi.org/vbulletin/member.php?s=&action=editavatar). The URL of the image is stored at:
http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif

[T'ai Chi]

Originally posted by Craig
You know, that slower yin-yang is strangely hypnotic to watch.


Hey, I need any advantage I can get for some people to take some of my opinions seriously. ;) ;)

[Aussie Thinker]

This question is interesting.

If most sceptics were honest we would HAVE to admit that mostly if there is NO evidence for something it probably does not exist.

Now as Sagan eminently stated this does not always apply but it is RARE that it doesn’t.

No evidence for paranormal = Paranormal does not exist
No evidence for God = God does not exist
No evidence for UFO’s = UFO’s do not exist..

Now the last is where it gets interesting..

We have NO evidence for the existence of aliens but what is the probability that aliens exist..

Very High I would say given the vastness of the Universe..

So in that case absence of evidence does not equal evidence of absence.. So why is it sometimes different..

We have to also incorporate other issues.. like logic, probability likelihood and general common sense (whatever that is).

In the above 3 examples for example..

Paranormal.. is illogical, everything ever known has had a natural explanation so therefore it is unlikely and illogical to assume paranormal explanation. At bes we could assume unusual unknown natural explanation..

God.. again similar to the paranormal, the existence of God is requires as an unnatural explanation for existence. Most of the Gods that have been raised would leave clear evidence for their existence and as NONE is available is is logically assumed that God does not exist.

UFO’s.. now we have already said that the existence of Aliens are likely due to probability and logic.. however have they visited us ??? Highly unlikely given the same vastness of the Universe( that makes their existence likely) and lack of evidence.

Conclusion…

Absence of evidence (and probability and logic) = evidence of absence


Tai,
Please slow down the Yin Yang.. it drives me nutty !

[T'ai Chi]

Originally posted by Yahweh

The reason you are getting a .php file is because this software stores binary files in a database. This isnt the same as storing it locally on a server. Because the binary information is stored in the database, the SRC attribute of the IMG tag has to link to a .php file rather than a GIF file. The PHP file is a script which reads the binary information from the database.


Ok that makes sense.

Thanks again for the slower animated t'ai chi symbol! :)

[Yahweh]

Originally posted by Craig
You know, that slower yin-yang is strangely hypnotic to watch.

Incidentally, I've got the urge to send all of my money to Yahweh...

<table><tr><td align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td></tr><tr><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td><td height="60" width="60" align="center" valign="middle">Send your money to me, Craig. You know you want to, you know it'll make you happy...</td><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td></tr><tr><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td><td height="60" width="60" align="center" valign="middle">http://img.villagephotos.com/p/2003-12/535625/99867520-YinYangSpin1.gif</td></tr></table>

[Aussie Thinker]

They look like little white sperms chasing little black sperms.. the slow version is a lot more compelling

[epepke]

It depends on the nature of the evidence or lack thereof.

In many real-world instances, there is evidence from somewhere else that suggests that there should be evidence. When that other evidence is strong, and the reasoning is strong, then the absence of evidence is evidence of absence to the strength of that claim.

For example, if there were a variation in the speed of light depending on the motion of the observer, then there should be evidence supporting the Michaelson-Morley experiment. If there were hidden local variables, then there should be evidence supporting Bell's Inequality. The null result of those experiments is strong evidence for the absence of variations in the speed of light and local hidden variables.

To say that concluding the absence of evidence to be evidence of absence is a logical fallacy is easy when the statement is isolated from other statements, but the ability to construct a reductio ad absurdum is also part of logic.

[Soapy Sam]

It depends how much absence of evidence you have accumulated. Just a little absence of evidence equates to a little evidence of absence, whereas a whole lot of absence...
...I give up. What's the answer?

[T'ai Chi]

Originally posted by Soapy Sam
It depends how much absence of evidence you have accumulated. Just a little absence of evidence equates to a little evidence of absence, whereas a whole lot of absence...
...I give up. What's the answer?

How can you accumulate absence? Is it even possible? Afterall, 0+0+0+... = 0 still no matter how much you add it. :)

I think you mean that if t_e is large, where t_e is the time spent looking for e, the evidence, then we can stop. But how large does t_e have to be before we stop?

[athon]

OK, here's my take on it.

I think you have to possess a certain way of thinking when it comes to how to treat evidence. I believe in humility in science - holding a belief with the idea constantly in your mind that you could be wrong.

Now, let's take the smurf concept. There is no evidence that they exist - do they not? As far as anything in science needs to be concerned, they don't, for now. We base no theories on them, we don't use them as the foundation for anything. For now. Should evidence come up, that evidence is compared with all standing concepts to see where it fits.

Too many people want solid, defining answers in a universe where our subjective understanding is liquid. We must be prepared to paint a universe with the colours we presently have available, whilst being able to touch it up when we discover new colours.

Athon

[Darat]

...snip...

We must be prepared to paint a universe with the colours we presently have available, whilst being able to touch it up when we discover new colours.

Athon [/B]

Don't need any new colours, the universe is beige http://www.npr.org/programs/atc/features/2002/jan/aas/020110.aas.html

[xouper]

If this thread demonstrates anything, it shows that a platitude, such as "absence of evidence is not evidence of absence," is no substitute for critical thinking.

[TheERK]

Originally posted by T'ai Chi


So no extra-terrestrials exist?

Are you fairly certain?

I tend to believe that we, humans, are evidence of extra-terrestrials. If we came to be by natural processes, then given enough planets with varying conditions, it might simply be inevitable (or extremely probable) that aliens exist. Of course, we don't have a full understanding of said conditions yet, so it's hard to say. But to say that there is no evidence that aliens exist might be like saying there's no evidence that bugs live in (insert some recently discovered, unexplored forest here).

[BillHoyt]

Originally posted by T'ai Chi


How can you accumulate absence? Is it even possible? Afterall, 0+0+0+... = 0 still no matter how much you add it. :)

I think you mean that if t_e is large, where t_e is the time spent looking for e, the evidence, then we can stop. But how large does t_e have to be before we stop?

We've been down this road before, Tr'olldini. The general discussion here concerns the epistemology of science. There is no pre-defined stopping criterion. Why must you keep insinuating that there should be? Why must you keep needling this inane point? We reach, through the constant probing of the hypothetico-deductive method and the intersubjective validation processes of peer review, a consensus. Each individual probe is based on the statistical methods you claim to be trained in. The methods that you constantly insinuate aren't good enough. With each sampling, our confidence level grows. Eventually, our certainty reaches high enough numbers that we call it quits. We say, "no, Tr'olldini, we're not wasting any more of our time, we're not wasting any more of our money on chasing down your boojums."

For one who keeps screaming about his degrees in math and statistics, you continue to evince a fundamental conceptual problem with uncertainty and statistics.

[T'ai Chi]

Originally posted by BillHoyt

There is no pre-defined stopping criterion. Why must you keep insinuating that there should be? Why must you keep needling this inane point?


The inane point is you suggesting I said that in my recent post in this thread. In fact, I was asking someone else what they thought about such things.


For one who keeps screaming about his degrees in math and statistics, you continue to evince a fundamental conceptual problem with uncertainty and statistics.

Yeah, I keep screaming about them. :rolleyes: Spare us the dramatics. --I will extend a challenge to you to for another friendly question answering contest in statistics and mathematics however. You are, of course, free to run the other way again. :)

[Nyarlathotep]

Originally posted by xouper
If this thread demonstrates anything, it shows that a platitude, such as "absence of evidence is not evidence of absence," is no substitute for critical thinking.

That's a really good point. The best one made on this thread so far, I think.

[BillHoyt]

Originally posted by T'ai Chi


The inane point is you suggesting I said that in my recent post in this thread. In fact, I was asking someone else what they thought about such things.

Yeah, I keep screaming about them. :rolleyes: Spare us the dramatics. --I will extend a challenge to you to for another friendly question answering contest in statistics and mathematics however. You are, of course, free to run the other way again. :)

Spare us, tr'olldini. Shall we trot out your past posts about science and the scientific method? The level of certainty varies with the quality (both statistical and procedural) of the data. There is no 100% certainty. There are no stopping criteria.

Cut out the game playing.

[T'ai Chi]

Originally posted by BillHoyt

Spare us, tr'olldini.


So is that a "no" from you then about the friendly statistics/mathematics contest part?


Shall we trot out your past posts about science and the scientific method?


And past posts have what exactly to do with current ones? Everyone has some past posts that they aren't proud of; we're human afterall. I'm not even going to go to Mudsling Land and post some of your less-than-impressive posts for all to see. Sorry. I'll stick to the relevant issues at hand.


Cut out the game playing.

I guess that is a "no" from you regarding the friendly contest then. And I got lots of questions all ready to go fer ya too.

[BillHoyt]

Originally posted by T'ai Chi
And past posts have what exactly to do with current ones? Everyone has some past posts that they aren't proud of; we're human afterall. I'm not even going to go to Mudsling Land and post some of your less-than-impressive posts for all to see. Sorry. I'll stick to the relevant issues at hand.
These were precisely relevant:
The level of certainty varies with the quality (both statistical and procedural) of the data. There is no 100% certainty.
Your post somehow overlooked them.

Stop playing games.

[zultr]

Why can't you simply accept the findings of Donald Rumsfeld and leave it at that?

BRUSSELS, June 6 [Reuters]: US Defence Secretary Donald Rumsfeld baffled NATO allies and journalists alike on Thursday by saying the greatest threats to Western civilisation may lurk in "unknown unknowns".

Rumsfeld was defending Washington's view that the United States and its allies could not wait for "absolute proof" before taking action against groups and states suspected of acquiring weapons of mass destruction.

"The message is that there are no knowns. There are things we know that we know. There are known unknowns, that is to say there are things we now know we don't know. But there are also unknown unknowns - things we do not know we don't know. So when we do the best we can and we pull all this information together, and we then say 'well, that's basically what we see as the situation', that is really only the known knowns and the known unknowns. And each year we discover a few more of those unknown unknowns," he said.

Acknowledging that his argument might sound like a riddle, Rumsfeld concluded with a flourish: "There is another way to phrase that, and that is that the absence of evidence is not evidence of absence… Absolute proof cannot be a precondition for action."

[Soapy Sam]

I heard Rumsfeld was awarded an (ironic) Plain English award for that little gem. Actually, it makes perfect sense to me, though it could have been better expressed.

Meanwhile, I should stress that my comment about accumulating absence, which seems to have triggered a row twixt BillHoyt and TaiChi WAS supposed to be a joke. Which is the (IRONY) smiley again?

[T'ai Chi]

Originally posted by BillHoyt

These were precisely relevant:


No, I meant bringing up what either of us posted in the past is not relevant to the current discussion.


Stop playing games.

You seemed to ignore the friendly challenge again; take 28!