Talk:Tautology

Some old discussion
it's funny cause "due to superfluous qualification" adds redundancy
 * I disagree; I think it specifies a certain type, but feel free to rewrite if you can get across the same meaning more elegantly.  &mdash;Triskaideka 16:44, 11 Oct 2004 (UTC)

In my opinion, "LCD display," "PIN number," and "ATM machine" are redundancies, not tautologies. Not all redundancies are tautologies. If I said "She is very, very attractive," I would be making a redundency (for emphasis), not a tautology. If I said "I'm a man-man," I'd sound ignorant, but the redundancy wouldn't be a tautology. In these cases, I would call them "repititions due to ignorance," not true tautologies (which attempt to elucidate, vainly.) Quadell (talk) 15:28, Aug 12, 2004 (UTC)
 * That was my understanding as well. However, much to my chagrin, I discovered that dictionary.com  and m-w.com  both give definitions that would seem to include the "linguistic tautologies" mentioned here.  I've edited the opening paragraphs of the article to more clearly indicate the distinction.


 * "Boys will be boys" and "Business is business" are surely logical tautologies, since they're statements. Are they really linguistic tautologies as well?  What makes them so -- the fact that they're cliches?  In my opinion, they're actually not redundancies.


 * While I'm asking questions, how does "Really existing socialism" mean that there is no socialism? It seems like we're missing some context that would help readers understand this example.    &mdash;Triskaideka 21:09, 31 Aug 2004 (UTC)


 * Since it's been a while and nobody's answered or objected to these concerns, I've rewritten those parts of the article. In particular, I rewrote the sentence about "really existing socialism", which I think was confused as it stood, to something that was more like what I thought it meant to say.   &mdash;Triskaideka 16:44, 11 Oct 2004 (UTC)

I am unhappy with the assertion that "the opposite of a tautology is a contradiction, which is a statement that is always false." Given the definition of a tautology ("A logical tautology is a statement that is true regardless of the truth values of its parts") this is not true. The opposite can either be a statement which is always false regardless of the truth values of its parts, or a statement which is always false regardless of the false values of its parts.


 * I think you're getting hung up on the wording. A tautology is a statement that is necessarily true, and a contradiction is a statement that is necessarily false.  We can (but, IMO, need not) elaborate on these definitions by saying that tautologies are always true, and contradictions are always false, regardless of the truth values of their parts; the meaning is the same.


 * In any case, I've added this clarification to the article; feel free to revise if you think more is needed. &mdash;Triskaideka 16:17, 4 Feb 2005 (UTC)

Linguistic examples
I deleted a recent addition from the article, for several reasons. Here is the text in case anyone disagrees.


 * Gun advocates such as NRA commonly used the slogan "If guns are outlawed, only outlaws will have guns". This is no doubt true by its words, but the user may argue that it's not exactly redundant, for his usage is actually stating "Once guns are outlawed, those who commonly commit crime (bad guys) today will still hold the existing guns and use them against those (good guys) who intend to protect themselves" in other words "Bad guys remain bad, good guys become victims for abiding the law".

For one thing, it's more of a logical tautology, but it was placed in the linguistic examples section (although that's only a reason to move it). More importantly, I worry that might be interpreted by readers as an attempt to push a certain POV regarding the issue of gun laws. The paragraph's point is more concerned with the issue of gun control than with the semantics of the slogan, and therefore I think it would be more appropriate for an article on gun control/laws/etc. than for this article.

Further, I worry that we're getting carried away with examples. It seems to me that the number of examples already present in the article is more than sufficient. A few representative cases should be fine; if the reader is interested, there are plenty more at List of redundant expressions, which is in this article's "See also" section. &mdash;Triskaideka 17:01, 8 Mar 2005 (UTC)


 * Is the redundant expressions page the ideal place to catalog tautologies? I wanted to post the example "All copyrights are the property of their respective owners," but it seems to me more relevant to this topic than to redundancies. A separate section or page that collects tautology examples would be word-nerd fun and perhaps of some value in refining one's sense of what is and isn't a tautology. --Stanky 12:49, 16 January 2006 (UTC)


 * How about we make a page for tautologies? -- ʀ6ʍ ɑ  ʏ89  21:17, 16 January 2006 (UTC)

Many of the linguistic tautology examples are very weak. It is completely acceptable to talk about the La Brea tar pits, or the Sierra Nevada moountains, or an ATM machine, while there is something wrong with "three part trilogy" (outside the context of a 6 parter). Does linguistic tautology mean "superficially redundant" or does it mean something more than that? It seems to mean superficially, but that's not what the article says. Also, recursive acronyms pre-date Dilbert: "ZWEI" the text editor is one example, though I didn't check the jargon file to see if it was the first.

Tautology and analytic statement
Can somebody tell me what is the difference? It would be worth to make this difference clear in the article as well.

--Seingalt 12:22, 21 July 2005 (UTC)

I don't understand...
...that example of subtle tautology with the senators. Please could someone explain, and perhaps consider reworking that part of the article for thickies like me! [UserID:Promsan|Promsan]144.178.184.77 09:46, 23 October 2005 (UTC)

I think the point centers on the use of the word "mainstream", meaning that if one was in the mainstream, one would be voting with the majority. So further describing a Senator as being out of the mainstream because he was not voting with the majority would be a redundancy. However, there may be an issue with terminology -- the members of the House of Representatives are not called Senators. Though it is possible for a Senator to have an opinion about a House bill, the statement may cause some confusion. Still 23:20, 28 October 2005 (UTC)

Comments from my talk page
From User talk:Chalst: Your comment for the revert made little sense. First, the article starts off with "In logic, a tautology is a statement which is true by its own definition" with emphasis on 'logic'--so a more rigorous and precise notion involving interpretations (or valuations) is required. Second the word stems from Wittgenstein wrt to logistic systems. Third, statements true by definition are called 'analytic', not tautologous.

The next sentence reads "All true statements of logic and mathematics are tautologies" which is incorrect unless it means that they are true under every interpretation. If we leave it as is then every contingent and actual truth is a tautology since they are true (but not in general logically) in logic (under some interpretation). There are other issues as well.

The word 'interpretation' is not necessarily wedded to model-theoretic notions. In fact, it is more "fundamental" than 'tautology'!

I hope the page is edited appropriately soon. Nortexoid 17:50, 31 October 2005 (UTC)
 * I don't recall seeing this page before--I have to say that I have some issues as well. The claim that "all true statements of mathematics are tautologies" seems to me practically the defining belief of logicism, a foundational school that has fallen into severe disfavor (but it would be a POV assertion even if logicism were the dominant school).
 * On a pickier note, the page currently claims that the mathematical symbol is $$\Vdash$$. I think you want $$\models$$; the former symbol is more often used for the forcing relation. --Trovatore 18:46, 31 October 2005 (UTC)


 * That was changed by me but reverted. To be fair, it is used for validity in some texts (e.g. Mendelsohn and Fitting's "First-order Model Logic"), but this usage is far from standard; hence my change.Nortexoid 21:15, 31 October 2005 (UTC)


 * Quick-and-dirty fix in place for these issues. I still think the page needs some serious work. I tend to think of a "tautology" as being a validity of the propositional calculus; statements of quantified predicate calculus can be true in every interpretation without being tautologies in my usage. --Trovatore 19:12, 31 October 2005 (UTC)


 * I think you are among most people when tending to think that. Aside from that, the rest of the introduction is abhorrent--e.g. "useless tautology"; "all statements are informative in some context"; "a tautology...is true regardless of the truth of its parts" (which wrongly suggests non-truth-functional); etc. Nortexoid 21:15, 31 October 2005 (UTC)

I'd like to point out that, before my rv, I don't believe I ever edited this page: it wasn't even on my usual watchlist, but only User:Chalst/watchlist. I rved the edit not becuase I thought there were no improvements in Nortexoid's edit, but because (i) on balance there was more harm than good in the edit, (ii) sorting out the good from the bad was N's job, and (iii) I didn't have time. Please feel free to edit the article, just don't try to impose modern preconceptions on ancient topics. Aristotle's "All As are A" is a tautology not of propositional logic, but of syllogistic. --- Charles Stewart 21:26, 31 October 2005 (UTC) There's plenty mentioned in the above that needs fixing here. --- Charles Stewart 20:05, 1 November 2005 (UTC)

"The late comedian Alan King used to tell this story"

Is the "used" in this sentence in the article itself a tautology? It would be strange if a late comedian continues to tell the story...

Angeles and Angels
I do not believe that "The Los Angeles Angels" should be considered a grammatical tautology, because, unlike "The La Brea Tar Pits", the two instances of the word "Angels" do not refer to the same thing.

"Angeles" is part of the name of the city, where "Angels" refers to the players of the baseball team. Thus "Los Angeles" is a necessary descriptor for the baseball players, distinguishing them from some other group of angels. This is not redundant in any way.

As a side note, the team now resides in Anaheim and it's official name is "The Los Angeles Angels of Anaheim". Though this is a recent change from "The Anaheim Angels" and is under legal dispute by the city of Anaheim. &mdash;preceding unsigned comment by Headybrew   (talk • contribs) 01:03, 30 November 2005

Separate out logical tautology
I really think it's a bit incongruous to have the logical concept discussed on the same page as these endless remarks about PIN numbers and so on; the two senses of the word have little to do with each other. How about two pages, tautology (logic) and tautology (linguistics), with tautology turned into a dab page? (I would be against making the linguistic meaning primary; the logical meaning is taught to ninth graders in geometry class, and is probably the first meaning a lot of people encounter.) --Trovatore 17:14, 23 March 2006 (UTC)


 * I'm ok with the dab suggestion. But I don't think 'linguistics' is the right word.. is should be something like speech, or writing, or grammar. Zargulon 17:25, 23 March 2006 (UTC)
 * You're right, "linguistics" isn't quite right. "Grammar" might be OK, but doesn't strike me as precise. "Speech" or "writing" would be fine except that there are two of them, and the subject matter is the same. How about "language"? (Language in the sense of verbal expression, not in the sense of Greek or Urdu.) --Trovatore 17:31, 23 March 2006 (UTC)

JA: The classical distinction is Tautology (logic) and Tautology (rhetoric). Jon Awbrey 18:02, 23 March 2006 (UTC)
 * (Rhetoric) sounds good enough to me.Zargulon 18:20, 23 March 2006 (UTC)
 * I agree with Trovatore's suggestion that the two concepts should have separate pages, and with Jon Awbrey's suggestion that these should be Tautology (logic) and Tautology (rhetoric).  dbtfz talk 01:26, 24 March 2006 (UTC)
 * Done. Both articles could probably use some cleanup. --Trovatore 02:34, 24 March 2006 (UTC)

So I started halfheartedly sorting out the pages linking here, and I ran into trouble on the second one, which was anthropic principle, which asserts that some find the "weak anthropic principle" to be a tautology. This is clearly not in the "PIN number" sense, but neither is it a tautology in the technical sense of mathematical logic. Which article should we expand to include this meaning, which comes from the discipline I sometimes call "rhetorical logic"? Or does it need a third article? --Trovatore 02:59, 24 March 2006 (UTC)
 * On reflection I'm pretty sure I don't want it in the current tautology (logic) article. Let's keep that one clean, even if it needs to be moved to tautology (mathematical logic) or some such. --Trovatore 03:00, 24 March 2006 (UTC)
 * I think Truism may be the "third article" you're suggesting.  dbtfz talk 03:03, 24 March 2006 (UTC)

Isn't the definition of the rhetorical form redundant?
This is how the rhetorical form is currently defined:

Tautology (rhetoric), use of redundant language that adds no information

Isn't the phrase "redundant language that adds no information" redunant? After all, if the language added further information, it would not be redundant.

Perhaps a change to either:

Tautology (rhetoric), use of redundant language

or

Tautology (rhetoric), use of redundant language (language that adds no information)

would be better.


 * Very ironic, C5ybr. I'm OK with it as it stands, but would have no problem with anyone changing it to your second example. BTW, you can sign your contibs with four "tilde"s (the "~" symbol). Durty Willy 01:42, 27 November 2006 (UTC)

In Physics
I've heard the word "tautology" used in physics to describe a method of predicting or simulating a complex system without accurately taking into account the actual causes of change within the system. For example, the method may accurately predict or chart behaviour within a system, but for all the wrong reasons (the math works, but the basis for its validity is unknown or mistaken. For example, non-heliocentric models of the movements of the solar system). I've seen the word used in SciAm in regards to "Grey Matter" and "Dark Matter" theories with promising (but currently unprovable) data, and i.r.t. other statistically accurate yet disputed theories. It seems to be in use within the physics and mathematics crowd, but I don't have any background to start a new article (Tautology (physics) or Tautology (mathematics)), and it's been a bitch finding reference on Google. I could be misinterpreting the word, but I'd be glad to make a new article if anyone can corroborate my understanding of it in this context. Otherwise, I'll "be bold" and blindly make a new stub ;) Durty Willy 02:08, 27 November 2006 (UTC)

Is this a joke ?
"Tautology (example), an example of tautology". &#x262D; мдснєтє тдлкЅТЦФФ 21:40, 17 February 2010 (UTC)

Probably a reference to  (although maybe not...) R Green —Preceding unsigned comment added by 188.220.32.32 (talk) 21:52, 17 February 2010 (UTC)

Funny thing is that's what brought me here. &#x262D; &emsp; мдснєтє тдлкЅТЦФФ 22:01, 17 February 2010 (UTC)

It is a joke, but not appropriate for an encyclopedia. It has to be considered vandalism now. If it persists, let's semi-protect the page. -Phoenixrod (talk) 06:06, 19 February 2010 (UTC)


 * Notified User talk:97.118.208.170 using uw-3rr for repeated attempts to insert the redlink. &mdash; MrDolomite &bull; Talk 03:57, 22 February 2010 (UTC)


 * IMHO it is within the degree of humour that an encyclopedia can carry. I would prefer something a bit less abstract, but in general I like the idea. Pitty it is gone. --Sascha.leib (talk) 09:08, 8 June 2010 (UTC)


 * I agree with Sascha.leib. The portal portal is an example of a page obviously meant to be humorous and it doesn't really contribute anything.  It just seems inconsistent to remove this. Meh.  What's done's done.  --Steven Weston (talk) 14:45, 11 November 2010 (UTC)


 * The above page is now at Wikipedia:Portal:Portal; maybe that namespace would be a suitable place for the version of this page being discussed. GreenReaper (talk) 22:15, 21 April 2018 (UTC)

woah, could someone merge some of these?
I watned to look up what is tautology, but there's 4 pages and that seems like a tad much — Preceding unsigned comment added by 152.250.1.179 (talk) 01:22, 15 March 2015 (UTC)

Tautonym
In the explanation of tautonym, "both identical" is a pleonasm. I have corrected & clarified. Steve8394 (talk) 21:06, 1 November 2015 (UTC)