ISF Logo   IS Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » General Skepticism and The Paranormal
 

Notices


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Reply
Old 21st June 2006, 02:25 AM   #1
Dr Adequate
Banned
 
Join Date: Aug 2004
Posts: 17,861
Is There A Name For This Fallacy?

Arguing that a precaution was unneccessary on (in effect) the grounds that it worked.

"Wearing seatbelts is compulsory, yet the number one cause of injury in car-crashes is seatbelts."

Unexamined alternative : if wearing seatbelts wasn't compulsory, the number one cause of injury would be flying head first through the windscreen.

"We spent all that money on fixing the Y2K bug, and yet nothing went wrong on 1st January 2000."

Unexamined alternative : if we hadn't spent the money lots of things would have gone wrong.

"The government says we have to vaccinate our children against the measles, but when did you ever hear of anyone dying of measles?"

Unexamined alternative : in countries without vaccination, "Don't count your children before the measles" is a proverb used when we would speak of chickens and eggs.

You get the picture.
Dr Adequate is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 02:44 AM   #2
athon
Guest
 
athon's Avatar
 
Join Date: Aug 2001
Posts: 9,279
I haven't come across a name, but have debated against people who have used this logic on several occasions. Man, it's infuriating.

I like to think of it as the 'alternative action' fallacy. An informed action was taken to prevent a consequence from occuring; that the consequence did not occur contributes no evidence to support the notion that the action was ineffective.

Athon
athon is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 03:06 AM   #3
Dr B
Critical Thinker
 
Join Date: May 2006
Posts: 483
Excellent thread!!!!

Yes, I have encountered this one lots as well in debates with woo's. Not sure of a specific name - but it is a kind of reasoning in a circle where a positive outcome is used to question the lack of a negative one. In other words - it kind of answers itself.....
Dr B is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 03:13 AM   #4
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Is this not a special class of the irrelevant conclusion, a.k.a. ignoratio elenchi, mode of argumentation? In itself, ignoratio elenchi is a subclass of the non sequitur.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 03:28 AM   #5
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 17,345
Couldn't we just label it ...


..nonsense?


Actually, non sequiteur is quite fitting, IMO, because it works both ways:

"Wearing a white hat while walking the streets of New York keeps the tigers away."

"But there are no tigers in the streets of NY!"

"See? It works!"

You cannot, from the incidence of injury with seatbelts, infer anything at all about the incidence of injury without seatbelts.

.... You can infer form other things that seatbelts probably reduce various injuries but promote injuries from seatbelts, of course.

Hans
__________________
Don't. Just don't.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 03:32 AM   #6
Mojo
Mostly harmless
 
Mojo's Avatar
 
Join Date: Jul 2004
Posts: 25,503
Is There A Name For This Fallacy?

If there wasn't one before, I think there is now:
Originally Posted by Dr Adequate View Post
Unexamined alternative.
All three examples rely on ignoring the potential consequences of not taking the precaution.
__________________
"You got to use your brain." - McKinley Morganfield

"The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky
Mojo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 04:56 AM   #7
Soapy Sam
NLH
 
Join Date: Oct 2002
Posts: 28,171
"Fallacy of the unexamined alternative".
Sounds good to me... but should we not examine some alternatives?
Soapy Sam is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 05:35 AM   #8
UrsulaV
Muse
 
UrsulaV's Avatar
 
Join Date: Dec 2004
Posts: 956
Hmm, since it sounds like a total failure to appreciate the success of these programs, I'd call it "argument from ingratitude." Or perhaps "the ingrate fallacy."
UrsulaV is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 06:25 AM   #9
Stellafane
Village Idiot.
 
Stellafane's Avatar
 
Join Date: Apr 2006
Posts: 6,888
I don't know whether there's an "official" name for this line of faulty reasoning. but I personally refer to this as the Challenger Syndrome. "Why do we have to be so careful when we launch space shuttles? None of them has ever blown up before."
Stellafane is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 06:54 AM   #10
bob_kark
Person of Hench
 
bob_kark's Avatar
 
Join Date: Oct 2005
Posts: 4,484
Originally Posted by UrsulaV View Post
Hmm, since it sounds like a total failure to appreciate the success of these programs, I'd call it "argument from ingratitude." Or perhaps "the ingrate fallacy."
I'd support argument from lunacy or argument from sheer stupidity.
__________________
"You may balk at this, but bob_kark's argument that all major world powers are controlled by a covert group of "insiders" is hopelessly flawed and totally circuitous." - Shemp
bob_kark is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 06:55 AM   #11
Rustle
Thinker
 
Join Date: May 2006
Posts: 126
ummm how about "Denying the Consequent"?

Usually it is the other way around, post hoc propter hoc. In you examples, there is a causation, not just a correlation. If

x = kids are vaccinated against measles
y = kids don't get measles,

it isn't just that x and y occur at the same time, but x causes y
Rustle is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:08 AM   #12
Wudang
BOFH
 
Wudang's Avatar
 
Join Date: Jun 2003
Posts: 9,383
I tend to think of it as cherry-picking data. Eg missing data - the cause, number and severity of injuries before seatbelts were made compuslory.
cf "missing the big picture"
__________________
Aphorism: Subjects most likely to be declared inappropriate for humor are the ones most in need of it. -epepke
Wudang is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:12 AM   #13
Hellbound
Merchant of Doom
 
Hellbound's Avatar
 
Join Date: Sep 2002
Location: Somewhere between the central U.S. and Hades
Posts: 10,124
Of course, the seat belt thing is not entirely an accurate comparison, either.

Seatbelts may be the number one cause of injury, because in any collision at more than walking speed their likely to leave bruising. However, they are FAR from the number one cause of death. And death rates clearly show that seat belts save lives. I think this one is a bit different, because seatbelts aren't meant to prevent any sort of injury, but to prevent death and reduce serious injury. I'd almost classify this as a strawman, because they are arguing that seatbelts don't prevent injury, when their primary purpose is to prevent death.
__________________
Science is like safety testing cars. You don't coddle a new theory; you slam it head-on into other theories. You sideswipe it, rear-end it, and roll it over at 60 mph. If it survives better than the old theory, it's good. And the way it fails, and under what conditions, gives you the information to make the next theory even better.

I reserve the right to be wrong.
Hellbound is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:39 AM   #14
Pardalis
Banned
 
Join Date: Mar 2006
Posts: 25,817
Originally Posted by Huntsman View Post
Of course, the seat belt thing is not entirely an accurate comparison, either.

Seatbelts may be the number one cause of injury, because in any collision at more than walking speed their likely to leave bruising. However, they are FAR from the number one cause of death. And death rates clearly show that seat belts save lives. I think this one is a bit different, because seatbelts aren't meant to prevent any sort of injury, but to prevent death and reduce serious injury. I'd almost classify this as a strawman, because they are arguing that seatbelts don't prevent injury, when their primary purpose is to prevent death.
Excellent.
Pardalis is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:44 AM   #15
atari24
Scholar
 
Join Date: Jan 2006
Posts: 105
Not really on topic, but as someone who would have died without a seatbelt, I had no problem with the severe bruising and rashing(it looked like someone slit my throat) that my seatbelt gave me. The alternative would have been a facefull of another car or an intimate relationship with my steering wheel.

[derail over, back on topic]
__________________
I have terepace and then various pow.
atari24 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:49 AM   #16
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Here is a most excellent web resource concerning fallacies of argumentation. It can provide hours of informative recreation.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 07:58 AM   #17
RSLancastr
 
RSLancastr's Avatar
 
Join Date: Sep 2001
Location: Salem, Oregon
Posts: 17,076
I believe it is a sub-class of Argumentum ad Rectum.
__________________
Who is "Kaz?" Read about her at www.StopKaz.com.

Curious about Sylvia Browne? Read about her at www.StopSylvia.com.

Ever wonder "What's the Harm?" with psychics, alternative medicine, etc?
RSLancastr is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 08:20 AM   #18
CFLarsen
Penultimate Amazing
 
CFLarsen's Avatar
 
Join Date: Aug 2001
Posts: 42,377
Originally Posted by Dr Adequate View Post
"We spent all that money on fixing the Y2K bug, and yet nothing went wrong on 1st January 2000."
Beacuse we spent all that money on fixing it.
__________________
SkepticReport.com
CFLarsen is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 08:31 AM   #19
Pardalis
Banned
 
Join Date: Mar 2006
Posts: 25,817
I think Huntsman said it pretty well. These arguments are fallacies because they are based on flawed assumptions:

"We spent all that money on fixing the Y2K bug, and yet nothing went wrong on 1st January 2000."

It assumes that there had to be something wrong to happen in 2000.

"The government says we have to vaccinate our children against the measles, but when did you ever hear of anyone dying of measles?"

It assumes that vaccination's purpose is to prevent death, when in fact it is to prevent desease and it's spread.
Pardalis is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 08:40 AM   #20
SteveGrenard
Philosopher
 
SteveGrenard's Avatar
 
Join Date: Oct 2002
Posts: 5,528
Originally Posted by Pardalis View Post

It assumes that vaccination's purpose is to prevent death, when in fact it is to prevent desease and it's spread.
except for one minor detail: measles does cause death and yes, vaccination also prevents measles and it's spread also.

Quote:

Measles remains an important cause of childhood mortality, especially in developing countries. In the joint Strategic Plan for Measles Mortality Reduction, 2001--2005, the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) targeted 45 priority countries* with high measles burden for implementation of a comprehensive strategy for accelerated and sustained measles mortality reduction (1). Components of this strategy include achieving high routine vaccination coverage (>90%) in every district and ensuring that all children receive a second opportunity for measles immunization. In May 2003, the World Health Assembly endorsed a resolution urging member countries to reduce deaths attributed to measles by half (compared with 1999 estimates) by the end of 2005 (2). This report updates progress toward this goal and summarizes recent recommendations on methods to estimate global measles mortality.

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5408a4.htm
edit: and somewhat closer to home than the so-called third world, there is this current news account:


Quote:
The fact that England is in the grip of the biggest measles outbreak since 1988 has been brought into sharp focus by the death of a 13-year-old boy.


Experts have repeated their warning to parents in Lancashire that many children in the county currently have no protection against the potentially fatal disease.

http://www.lep.co.uk/ViewArticle2.as...icleID=1574179
__________________
"We are facing a neurosis at the level of an entire civilization” Pierre Rehov

Last edited by SteveGrenard; 21st June 2006 at 08:46 AM.
SteveGrenard is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:01 AM   #21
Hellbound
Merchant of Doom
 
Hellbound's Avatar
 
Join Date: Sep 2002
Location: Somewhere between the central U.S. and Hades
Posts: 10,124
Originally Posted by Pardalis View Post
I think Huntsman said it pretty well. These arguments are fallacies because they are based on flawed assumptions:

"We spent all that money on fixing the Y2K bug, and yet nothing went wrong on 1st January 2000."

It assumes that there had to be something wrong to happen in 2000.

"The government says we have to vaccinate our children against the measles, but when did you ever hear of anyone dying of measles?"

It assumes that vaccination's purpose is to prevent death, when in fact it is to prevent desease and it's spread.
I have to disagree, my argument applies only to the seat belt issue. There are more injuries, sure, I can believe that. But there are fewer debilitating injuries and fewer deaths, and these are the things seatbelts were intended for (specifically to reduce death by keeping the occupant from being thrown outside the vehicle, other concerns were secondary).

The other two aren't strawman fallacies, they are of a different nature. Not sure what to call them, though, but Denying the Consequent seems pretty close:

Vaccination for measles should reduce measles deaths.
We vaccinate.
Measles deaths are reduced.

The view from the first post:
There are few measles deaths.
Vaccination is used to prevent measles deaths.
Vaccination prevents few deaths.

I dunno, though, may be a Correlation-Causation fallacy too. Hard to pin down. Seems more like a combination of other fallacies.

Disclaimer: I am not trained in formal logic, except by self-training. I f I am full of $hit, please feel free to tell me so
__________________
Science is like safety testing cars. You don't coddle a new theory; you slam it head-on into other theories. You sideswipe it, rear-end it, and roll it over at 60 mph. If it survives better than the old theory, it's good. And the way it fails, and under what conditions, gives you the information to make the next theory even better.

I reserve the right to be wrong.
Hellbound is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:04 AM   #22
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Originally Posted by Pardalis View Post
I think Huntsman said it pretty well. These arguments are fallacies because they are based on flawed assumptions:
Er, I think you missed Dr Adequate's central point. Each of the examples given in the OP are indeed fallacies stemming from flawed assumptions of causality. However, they have a common essence in that the effectiveness of a precaution is mistaken for evidence that the precaution was unnecessary.

Another example, if such helps, that might assist in further clarifying the matter goes as follows:
This example is typed in bold italics to make it noticeable. Since you noticed it easily from the rest of the text, I needn't have bothered about the bold italic typeface.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:08 AM   #23
Pardalis
Banned
 
Join Date: Mar 2006
Posts: 25,817
I think SteveGrenard is right, the flawed assumption in this case is that the measles don't cause death, wich in fact it does in children.

I'm not trained in formal logic either Hunts. But your right, it might be a combination of many fallacies.
Pardalis is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:10 AM   #24
Hellbound
Merchant of Doom
 
Hellbound's Avatar
 
Join Date: Sep 2002
Location: Somewhere between the central U.S. and Hades
Posts: 10,124
Originally Posted by Anacoluthon64 View Post
Er, I think you missed Dr Adequate's central point. Each of the examples given in the OP are indeed fallacies stemming from flawed assumptions of causality. However, they have a common essence in that the effectiveness of a precaution is mistaken for evidence that the precaution was unnecessary.

Another example, if such helps, that might assist in further clarifying the matter goes as follows:
This example is typed in bold italics to make it noticeable. Since you noticed it easily from the rest of the text, I needn't have bothered about the bold italic typeface.

'Luthon64
Well, I think I had a valid point regarding seatbelts, as preventing all injuries was not the design goal...preventing death was (with reducing injury severity as the means). There's a bit of strawman in that one, even if it wasn't the good Doc's central point

But you're right about the other two, and I addressed it a bit in my post just before yours.
__________________
Science is like safety testing cars. You don't coddle a new theory; you slam it head-on into other theories. You sideswipe it, rear-end it, and roll it over at 60 mph. If it survives better than the old theory, it's good. And the way it fails, and under what conditions, gives you the information to make the next theory even better.

I reserve the right to be wrong.
Hellbound is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:33 AM   #25
Pardalis
Banned
 
Join Date: Mar 2006
Posts: 25,817
Originally Posted by Anacoluthon64 View Post
Er, I think you missed Dr Adequate's central point. Each of the examples given in the OP are indeed fallacies stemming from flawed assumptions of causality. However, they have a common essence in that the effectiveness of a precaution is mistaken for evidence that the precaution was unnecessary.

Another example, if such helps, that might assist in further clarifying the matter goes as follows:
This example is typed in bold italics to make it noticeable. Since you noticed it easily from the rest of the text, I needn't have bothered about the bold italic typeface.

'Luthon64
Ah, now I get it. That's a very good point, very enlightening.

I guess I was focusing on the initial false assumptions.

The one about what the end result of the precaution should be:

"Seat belts should prevent injuries" (they prevent death)

and the false assumptions about what the threat is:

"the W2K bug" (wich happened to never have been a threat)
"the measles doesn't cause death" (wich does)

ETA: btw, how do we conjugate "measles", is it plural?

Last edited by Pardalis; 21st June 2006 at 09:42 AM.
Pardalis is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:35 AM   #26
Arkan_Wolfshade
Philosopher
 
Arkan_Wolfshade's Avatar
 
Join Date: Jan 2006
Posts: 7,158
Denying the antecedent maybe?
P1: If A then B;
P2: Not A;
C: Therefore, not B.

P1: If people die from measles then vaccination should be required.
P2: People don't die from measles.
C: Therefore, vaccination should not be required.
__________________
Amy: You should try homeopathic medicine, Bender. Try some zinc.
Bender: I am forty percent zinc.
Amy: Then take some echinacea, or St. John's Wort.
Professor: Or a big fat placebo. It's all the same crap.
Arkan_Wolfshade is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 09:48 AM   #27
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Originally Posted by Huntsman View Post
... but Denying the Consequent seems pretty close ...

Disclaimer: I am not trained in formal logic, except by self-training. I f I am full of $hit, please feel free to tell me so
By your leave, then, in inferential logic, denying the consequent and affirming the antecedent are both valid forms of argumentation, while affirming the consequent and denying the antecedent are not. Symbolically,

P => Q (if P then Q) is our basic rule of inference.
  1. Affirming the antecedent: P is true, therefore Q is true - valid
  2. Denying the consequent: Q is false, therefore P is false - valid
  3. Affirming the consequent: Q is true, therefore P is true - invalid
  4. Denying the antecedent: P is false, therefore Q is false - invalid

Try this with P = "you can read" and Q = "you know the alphabet":
  1. You can read therefore you know the alphabet.
  2. You do not know the alphabet therefore you cannot read.
  3. You know the alphabet therefore you can read.
  4. You cannot read therefore you don't know the alphabet.

The last two do not necessarily follow because you needn't have mastered the art of reading despite knowing the alphabet.

Also, I am not at all contesting the validity of your strawman assessment of the seatbelt case - it's an astutely reasonable one. I merely wish to point out that classifying it as a strawman can only be justified upon providing information not contained in its premises as given, and that even without such further information the argument is not a valid one.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:00 AM   #28
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Originally Posted by Pardalis View Post
ETA: btw, how do we conjugate "measles", is it plural?
Hmm, "conjugate" is something one usually does to verbs, so I don't quite follow your meaning. As is the case with, say, hives or acne, we don't distinguish any numerical amount of measles, so it will always be a case of "measles."

I'll grant you though that someone contracting a solitary "measle" and then "conjugating" it raises several intriguing possibilities...

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:05 AM   #29
Pardalis
Banned
 
Join Date: Mar 2006
Posts: 25,817
Originally Posted by Anacoluthon64 View Post
Hmm, "conjugate" is something one usually does to verbs, so I don't quite follow you meaning. As is the case with, say, hives or acne, we don't distinguish any numerical amount of measles, so it will always be a case of "measles."

I'll grant you though that someone contracting a solitary "measle" and then "conjugating" it raises several intriguing possibilities...

'Luthon64
LOL

I meant is the measles a plural word wich we would have to conjugated plurally a verb to it? (sorry, I'm French)

Do I say: the measles do cause death
or: the measles does cause death
Pardalis is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:13 AM   #30
Hellbound
Merchant of Doom
 
Hellbound's Avatar
 
Join Date: Sep 2002
Location: Somewhere between the central U.S. and Hades
Posts: 10,124
Originally Posted by Anacoluthon64 View Post
By your leave, then, in inferential logic, denying the consequent and affirming the antecedent are both valid forms of argumentation, while affirming the consequent and denying the antecedent are not. Symbolically,

P => Q (if P then Q) is our basic rule of inference.
  1. Affirming the antecedent: P is true, therefore Q is true - valid
  2. Denying the consequent: Q is false, therefore P is false - valid
  3. Affirming the consequent: Q is true, therefore P is true - invalid
  4. Denying the antecedent: P is false, therefore Q is false - invalid

Try this with P = "you can read" and Q = "you know the alphabet":
  1. You can read therefore you know the alphabet.
  2. You do not know the alphabet therefore you cannot read.
  3. You know the alphabet therefore you can read.
  4. You cannot read therefore you don't know the alphabet.

The last two do not necessarily follow because you needn't have mastered the art of reading despite knowing the alphabet.

Also, I am not at all contesting the validity of your strawman assessment of the seatbelt case - it's an astutely reasonable one. I merely wish to point out that classifying it as a strawman can only be justified upon providing information not contained in its premises as given, and that even without such further information the argument is not a valid one.

'Luthon64
I think Denying the Antecedent was what I mean. I can't remember all the names ;P I knew the idea I was thinking of, but I can never keep the names straight Thanks!

Hopefully my example made it clearer what I was getting at

And true about the seatbelt, it's a combination of factors, but even within the argument itself it falls into the same trap I was trying to point out but named incorrectly (I knew I should have double-checked that).

So, could this be some sort of version of Denying the antecedent?
__________________
Science is like safety testing cars. You don't coddle a new theory; you slam it head-on into other theories. You sideswipe it, rear-end it, and roll it over at 60 mph. If it survives better than the old theory, it's good. And the way it fails, and under what conditions, gives you the information to make the next theory even better.

I reserve the right to be wrong.
Hellbound is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:20 AM   #31
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Originally Posted by Pardalis View Post
(sorry, I'm French)
That's hardly your fault...

Originally Posted by Pardalis View Post
Do I say: the measles do cause death
or: the measles does cause death
Normally one would say, "measles cause death," i.e. treat "measles" as a plural.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:31 AM   #32
Anacoluthon64
Defollyant Iconoclast
 
Anacoluthon64's Avatar
 
Join Date: Mar 2006
Posts: 1,026
Originally Posted by Huntsman View Post
Thanks!
Don't mention it.


Originally Posted by Huntsman View Post
So, could this be some sort of version of Denying the antecedent?
Superficially it seems to follow a similar pattern, but in terms of the P => Q phraseology, it is more like saying "Q is true, therefore P has no effect on Q" simply by hiding the "if P then Q" part.

Therefore the label obscuring the antecedent may be more fitting.

'Luthon64
__________________
"The cynics were watchdogs terrifying malefactors. They tried to expose falseness and conceit. That's why their name is still spoken with a snarl." — Petr Skrabanek, In Defence of Destructive Criticism.
Anacoluthon64 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 10:53 AM   #33
brodski
Tea-Time toad
 
brodski's Avatar
 
Join Date: Mar 2005
Posts: 15,500
Originally Posted by Pardalis View Post
LOL

I meant is the measles a plural word wich we would have to conjugated plurally a verb to it? (sorry, I'm French)

Do I say: the measles do cause death
or: the measles does cause death
"Measeles does", we usualy don't bother with the "the" either.
brodski is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 11:13 AM   #34
tsg
Philosopher
 
tsg's Avatar
 
Join Date: Sep 2005
Posts: 6,771
Originally Posted by Pardalis View Post
LOL

I meant is the measles a plural word wich we would have to conjugated plurally a verb to it? (sorry, I'm French)

Do I say: the measles do cause death
or: the measles does cause death
The general rule most USians follow is, if it sounds plural, it's plural; if it sounds singular, it's singular; regardless of whether or not the thing it's describing is one or many. Especially with group names.

The Yankees do, but New York does. Measles do, rubella does. Etc.

The Brits have their own rules which appear to be largely based on "do the opposite of the Americans".
__________________
Being offended by someone questioning your beliefs is a sign that you should be questioning them.

In the beginning there was nothing. And the Lord said "Let There Be Light!" And still there was nothing, but at least now you could see it.
tsg is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 01:51 PM   #35
Soapy Sam
NLH
 
Join Date: Oct 2002
Posts: 28,171
No we doesn't!
Soapy Sam is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 01:52 PM   #36
Arkan_Wolfshade
Philosopher
 
Arkan_Wolfshade's Avatar
 
Join Date: Jan 2006
Posts: 7,158
Originally Posted by Soapy Sam View Post
No we doesn't!
Just remember, "y'ins" is the plural of "y'all".
__________________
Amy: You should try homeopathic medicine, Bender. Try some zinc.
Bender: I am forty percent zinc.
Amy: Then take some echinacea, or St. John's Wort.
Professor: Or a big fat placebo. It's all the same crap.
Arkan_Wolfshade is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 02:05 PM   #37
Rasmus
Philosopher
 
Rasmus's Avatar
 
Join Date: Jul 2005
Posts: 6,343
Originally Posted by Pardalis View Post
"The government says we have to vaccinate our children against the measles, but when did you ever hear of anyone dying of measles?"

It assumes that vaccination's purpose is to prevent death, when in fact it is to prevent desease and it's spread.
I almost died of the measles; I was told that another patient in the ICU at the same time wasn't quite as lucky, and I don't know what happened to the third.
Rasmus is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st June 2006, 02:12 PM   #38
brodski
Tea-Time toad
 
brodski's Avatar
 
Join Date: Mar 2005
Posts: 15,500
Originally Posted by tsg View Post
The Brits have their own rules which appear to be largely based on "do the opposite of the Americans".
Oh, we've got some brilliant ones, for instance in officialdom "the Government" is plural, but "the government" is singular.
brodski is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd June 2006, 12:24 AM   #39
rdaneel
Master Poster
 
rdaneel's Avatar
 
Join Date: Oct 2003
Location: I'M IN THE PHONEBOOK! I'M SOMEBODY!!!
Posts: 2,476
As a variation on the Y2K question. I wonder how often IT departments find themselves having to fight for their budgets because "The current system runs so smoothly, why do we need to spend more money on it?"
__________________
"Let me guess, my theories appall you, my heresies outrage you, I never answer letters, and you don't like my tie." - The Doctor

"Any sufficiently analyzed magic is indistinguishable from science!" - Agatha Heterodyne

rdaneel is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd June 2006, 01:26 AM   #40
Rustle
Thinker
 
Join Date: May 2006
Posts: 126
Originally Posted by Anacoluthon64 View Post
By your leave, then, in inferential logic, denying the consequent and affirming the antecedent are both valid forms of argumentation, while affirming the consequent and denying the antecedent are not. Symbolically,

P => Q (if P then Q) is our basic rule of inference.
One of the original statements was
"The government says we have to vaccinate our children against the measles, but when did you ever hear of anyone dying of measles?"

Which I would restate as something like
P = The gov. mandates measles vacc. (true)
Q = deaths from measles are rare (true)

So set up correctly, P=>Q, if the gov vaccinates, then deaths from measles will be rare

HOWEVER

From the way the question is posed, most people wouldn't draw the right causality. Instead of "if P, then Q" they would think just "P, and Q". So, would "Denial of Causality" work?

They are denying that P causes Q; denying that vaccines are the cause of measles deaths being rare.

I'm not sure its a real logical fallacy, so much as just being stupid.
Rustle is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » General Skepticism and The Paranormal

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 06:36 PM.
Powered by vBulletin. Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
© 2014, TribeTech AB. All Rights Reserved.
This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.