Talk:Non sequitur (logic)

message: I may be nitpicking here, but according to the article, if either of the given examples had "If and only if A, then B" as their first premise, then they would be valid and non-fallacious.  I would agree that they would no longer be non sequiturs, but surely they would still be non-valid and fallacious, because "If and only if I am a cat, I am a mammal." and "If and only if I am in Tokyo, I am in Japan." are both false premises - i.e., cats are not the only mammals, and Tokyo is not the only location in Japan. 
:Actually, the article is correct, in the sense that its logic is correct.  According to the definition of valid they are true as well.  valid just means that you can write the deduction as an if statement that is always true--and recall that if the premise of an if statement is false, the statement itself is still true.  So, to test the validity on one of the examples, we would write  "If (if and only if I am a cat, I am a mammal) and (I am a mammal), then (I am a cat)" is clearly true, even when the first premise of the statement is false.  Validity has to do with the soundness of the logic, not the truthfulness of its premises.  Furthermore, since fallacies are errors in the logic of a deduction, the claim of non-fallaciousness also holds.
:A hyperbolic example of non sequitur logic would be, "A bus is going through Wetumpka, Alabama. At the first stop, 3 three people get on. At the next one, 12 people get on and 2 get off. After that 5 more people get on. What is the bus driver's name?".   — Preceding unsigned comment added by Mastermike14 (talk • contribs) 05:27, 21 September 2011 (UTC)
replies: text: Basically, the aforementioned arguments would be valid and non-fallacious but also unsound. Shawnc 11:00, 29 January 2006 (UTC)
replies: text: As far as I can tell, it sounds as if the non-sequitur argument would be correct if the initial premise (A) is the only possible premise that would lead to (B).  We have to assume that that "If and only if A" is true for a non-sequitur to be correct logic.  That is the reason why a non-sequitur is false; this assumption that "If and only if A, then B" is true.  Though not stated in the logic of a non-sequitur, this is the main problem.  The fact that a non-sequitur assumes the "If and only if" condition is what makes it false...the way to correct it (a point that the first commenter missed) is not only to merely change the reasoning, but also to change the fact itself.
I'm arguing against my instinct here, but should that jab about advertising be in there, without a link to at least one advert that exemplifies a non-sequitur in a non-humourous manner?  Offhand I can't think of one that could be linked to, but without that, it's a bit of ad hominem without any supporting reference. 82.40.136.135 20:49, 12 February 2006 (UTC)
thread_title: If and only if

message: The American Heritage Dictionary also defines non-sequitur as a statement for which no response is appropriate or reasonable.  Should that definition be included in this article? Fishhead64 22:54, 17 July 2006 (UTC)
thread_title: Other uses

message: The disambiguation page suggests a non-sequitur is either a) absurd/comical or b) formally illogical. In other words, you find non-sequiturs either in a deliberately humourous or logical context. Most non-sequiturs, however, crop up in everyday speech or argument where people frame their arguments poorly in the heat of the moment. These ordinary non-sequiturs are neither intentionally absurd/comical nor statements of formal logic -- they're just everyday slips or, in the case of political statements, carefully calculated "weasel words". The last part of this article (after the formal logic bit) touches on this.
I feel that "everyday non-sequiturs" need to be covered more extensively. There are lots of examples in advertising and political speeches. There are also examples in psychology, where a person's tendency to conclude things about themselves that "don't follow" leads to depression or other forms of mental illness. This is what the "hair" example alludes to, but there's much more to say. Untangling non-sequiturs is one goal of psychiatric treatments like cognitive therapy.
Marcusswann 10:48, 14 November 2006 (UTC)
thread_title:  More on everyday non-sequiturs?

message: Example one I think could be more concise.
   1. If A is true, then B is true.
   2. B is stated to be true.
   3. Therefore, A must be true.
Would be better if you said
   1. All bananas are fruits.
   2. This is a fruit.
   3. Therefore, this fruit is a banana.
If you would rather A's and B's just substitute them in. An explaination could be:
   1. All A's are B's.
   2. This is a B.
   3. Therefore, this must be an A.
A's are a subset of B's from premise one; however, no mention is made of the subset of B's and, therefore, subset B may very well include items other than A's. Therefore, this is a non sequitur.
The key is that the initial example is convoluted (in my opinion).
:I believe the initial example is formulated according to the standard procedure on articles concerning logic. It is also quite clear and a much better general example of the subject than yours which is much more specific. There are more specific examples in the article. Of course, since you didn't sign your comment I don't know which version of the article you had before you so please do so in the future. Vadigor (talk) 19:20, 5 August 2008 (UTC)
thread_title:  Example 1 

message: Could someone please think of an example of non sequitur that isn't an undistributed middle? 64.90.198.6 00:27, 13 December 2006 (UTC)
thread_title:  Examples 

message: I was just wondering whether this should be merged or linked with the page Correlation is not causation? DeathscytheH64 23:25, 8 May 2007 (UTC)
thread_title: Relation to Causation Article

message: I believe this section should somehow include Ann Coulter, no explanation is necessary. Theonlysilentbob 18:22, 4 October 2007 (UTC)
thread_title:  Ann Coulter 

message: "'If my hair looks nice, all people will love me.' However, there is no real connection between your hair and the love of all people."
I think that this is totally unsound. How does physical appearance not apply to the feelings of others towards the one possessing that appearance?  —Preceding unsigned comment added by Hierophantasmagoria (talk • contribs) 07:38, 27 January 2008 (UTC)
replies: text: It seems like you do not understand the nature of the non sequitur in question. While it is true that physical appearance 'may' influence others it most definitely will not make 'everyone' love the person. This is a non sequitur coupled with (or derived from) a faulthy generalization. Vadigor (talk) 20:49, 5 August 2008 (UTC)

text: Yes that is unsound. Thats why its a logical fallacy.  — Preceding unsigned comment added by 75.167.99.93 (talk) 20:08, 18 September 2011 (UTC)
thread_title:  Hair 

message: I disagree absolutely that "weasel word" be merged with the totally esoteric and abstruse article "non sequitur (logic)". We should accept that readers will not be looking for "non sequitur" but most certainly for "weasel word", because that is the usual expression. Dieter Simon (talk) 23:42, 1 August 2008 (UTC)
replies: text: It should not be merged. The subjects only have some overlap and neither is a subset of the other. Chillum 17:56, 18 January 2009 (UTC)
thread_title:  Discussion whether to merge the article "weasel word" with " non sequitur (logic)" 

message: I'm having trouble parsing the first example:
"If you buy this car your family will be safer." (While some cars are safer than others, they will most likely decrease instead of increase your family's overall safety.)"
If someone actually said that to me in RL, I would assume they meant it was a safer car than the one I was currently driving. How is that an example of a non sequitur? WTF does the bracketed text mean?
I am so very confused. This really needs to be clarified.  —Preceding unsigned comment added by 59.167.120.19 (talk) 15:16, 26 August 2008 (UTC)
replies: text: I agree; this article seems to equate logically imprecise statements with logically invalid ones. It seems reasonable to assume that such a statement would imply safety over some previously discussed or implied alternative, such as the family's current car or another they were choosing. Similarly, nobody expects <I>all</I> people to actually <I>love</I> them when they buy something, so the cell phone example is a better example of exaggeration than non sequitur (although this is a bit of a non sequitur, since realistically, will a phone really change people's views of you?). I think there are too many legitimate, unquestionable, generic examples of non sequiturs to justify using these sketchy ones.  Eebster the Great (talk) 03:11, 12 December 2008 (UTC)
thread_title:  Confused 

message: Maybe the in-Wikipedia use of a very particular kind of non sequitur should be mentioned - Reductio ad Pokémon, like in:  (stated during a deletion discussion over ). Habbit (talk) 19:33, 2 February 2009 (UTC)
thread_title:  Use of non-sequitur in Wikipedia discussions 

message: I seems to me strange, that the current Non sequitur article is not a redrect to this one... --Alogrin (talk) 10:25, 21 February 2009 (UTC)
thread_title:  What is the current article [[Non sequitur]]? 

message: I am a lawyer and I don't know of any "special applicability in law." As far as I know it means exactly what it means in Latin. 67.161.74.64 (talk) 21:34, 26 January 2010 (UTC)
thread_title:  What is the "formal legal definition"? 

message: Need some guidance here..
Eminem's song titled Sing For The Moment, "it's all political, if my music is literal, and I'm a criminal how the f***, can I raise a little girl."
Here is how I dissected it:
If I am criminal, I can not raise a little girl.
If A, B can not be true.
That sounds to me like a non sequitur. Is non sequitur the right term to use for this example? Would that make a good example on this page? Or does it belong to another logic-related article?  —Preceding unsigned comment added by Colorsontrial (talk • contribs) 04:34, 6 November 2010 (UTC)
replies: text: No, that is not a good example of a non sequitur. Eminem's statement is rational and logically well-motivated in context. The full passage is:
"You need to spew, don't hesitate to produce air guns.  
That's why these prosecutors wanna convict me,  
Swiftly just to get me off these streets quickly.  
But all their kids been listen to me religiously,  
So I'm signin' CDs while police fingerprint me.  
They're for the judges daughter, but his grudge is against me.  
If I'm such a f#*!in' menace, this s#*! doesn't make sense, Pete.  
It's all political; if my music is literal, and I'm a criminal,  
How the f#*! can I raise a little girl?   
I couldn't. I wouldn't be fit to..."
In other words,  
IF ( my music is literal ) AND ( I am a criminal )  THEN ( I would not be fit to be a parent )
Eminem is correct, thus there is no non-sequitur.
Q.E.D.  
--FeralOink (talk) 23:15, 3 February 2013 (UTC)
thread_title:  Eminem's Lyrics - Is this a good example for a non sequitur? 

message: The "normal speech" section says non sequitur describes "a statement in which premise and conclusion are totally unrelated" (my emphasis), but in all of the examples the premise and conclusion are very obviously related: phones are related to image, pet food is related to dogs, and rain is related to sun. In the first example, the article correctly says that "there is no direct relation" between the two, but that is a very different thing to "totally unrelated". Examples of non sequiturs would be more in the line of "If you do not buy this type of pet food, the sun will not shine."  Scolaire (talk) 18:01, 29 September 2011 (UTC)
thread_title:  Examples - normal speech 

message: It would be nice if there was a phonetic spelling of the words in the header.  — Preceding unsigned comment added by Vaccano (talk • contribs) 20:47, 20 December 2012 (UTC)
thread_title:  Pronunciation Guide 

message: IF YOU HAVE TWO Non sequitur (logic) WORDS OR PHASES OR SENTENCES OR ANY COMBINATION OF THESE. IN A ROW OR SENTENCE. 
THENCE, THEN YOU HAVE ?  — Preceding unsigned comment added by 74.178.222.20 (talk) 06:27, 9 November 2013 (UTC)
thread_title:  IF YOU HAVE TWO Non sequitur (logic) 

message: The note states "That would still be "false"."
The premise of "not even wrong" is explicitly describing something as not-false.  You are saying that something not-false is false.  — Preceding unsigned comment added by 70.114.194.209 (talk) 00:27, 27 June 2015 (UTC)
thread_title:  Regarding 22:43, 26 June 2015‎ edit by McGeddon 

message: Article needs to explain how it's pronounced. 
--88.88.251.162 (talk) 13:26, 18 August 2016 (UTC)
thread_title:  Greetings, comrades. 

message: The lead section states that non sequitur is a logical fallacy, which does not belong to any of the named subclasses of logical fallacies. This means that this article can only concern with a general description of logical fallacies. The entire section Logical constructions actually discusses the named subclasses of logical fallacies. Additionally, logical fallacy is a synonym for formal fallacy. Therefore I propose to merge this article to Formal fallacy. Petr Matas 15:33, 12 April 2018 (UTC)
replies: text: . Petr Matas 14:22, 2 May 2018 (UTC)
thread_title:  Merge to [[Formal fallacy]]