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The internet smilies section doesn't really belong in an article about negation. While the smiley is created using a symbol for negation, it has nothing to do with the concept of negation, which is the topic of the article. 15:48, 5 October 2005 (UTC)

Probably because there doesn't seem to be a proper page about the ¬ character, which is what I was looking for when I found this article... --Beeurd (talk) 09:37, 16 September 2008 (UTC)

Re move of page to logical negation[edit]

Earlier today QQ moved this page to logical inequality, with as far as I can tell no prior discussion. I've now moved the page back. This is the second time that QQ has moved this page there. The first time the page was moved back by Lowellian. In my view this is a highly inappropriate name for this page, since the article also talks about term negation as used in grammar. What might be a good thing would be to create separate pages for the "negation (grammar)" and "negation (logic)" or "logical negation" and make this a disambiguation page, however this would have to be discussed and agreed to here first.

Please no further moves of this page without discussion and agreement here.

Paul August 17:49, 28 May 2006 (UTC)

Separating page is a good idea, but I don't think it is possible. The main reason is that people will revert back after doing this!!! In my opinion, if you think moving article EACH TIME requires discussion, you should talk to the committee of wikipedia. But I respect with your action, don't worry. QQ 18:00, 28 May 2006 (UTC)

Thanks for your "respect". As for making this into seperate articles, If it really is the right thing to do, I'm sure we could get a consensus for that. In that case reversion against consensus, would not stand. As i said on my talk page: ":... moving pages which are likely to be non-controversial, like simple misspellings etc. usually don't require any discussion. However for other moves ... it is always best to start a discussion on the talk page first." Paul August 18:24, 28 May 2006 (UTC)

For what it's worth, I'd support the split into "negation (grammar)" and "negation (logic)", making "Negation" a disambiguation page. That would make the other two links (album and comic) less obtrusive at the top. Eric Qel-Droma 13:25, 30 May 2006 (UTC)
I would also support splitting the article into two separate pages on grammar and logic/mathematics; not sure that mathematical negation and logical negation require separate treatment. Smerdis of Tlön 13:45, 30 May 2006 (UTC)

Proposed split[edit]

JA: Oppose for now. First off, negation (grammar) does not make sense, as negation is a semantic topic, not a purely syntactic one. The classical distinction would make it negation (rhetoric), and that big an umbrella would give folks rheum to discuss just about anything that comes to mind. Maybe someday, maybe soon, but right now the article is not big enough to justify it, and mostly needs to be better organized internally, say with a subhead for "rhetorical considerations". Jon Awbrey 15:40, 30 May 2006 (UTC)

Well it's not just a question of article size. I see it as more a question of utility, having separate articles would allow other articles to link with more specificity. Paul August 18:01, 30 May 2006 (UTC)

JA: Okay, I guess. How about something analogous to what we did for Tautology (logic) and Tautology (rhetoric)? But it still seems advisable to keep Negation for the primary logical meaning, instead of creating more havoc with Logical negation (already directed here), or Negation (logic) (a constant PITA to use as a link). Jon Awbrey 18:12, 30 May 2006 (UTC)

One other problem is that we really are not talking about separate subjects here. Grammatical negation clearly relates to logical negation; and various other sorts of negation, such as negation in mathematics or negation in computer programming, are likewise aspects of the same phenomenon: all involve the use of symbols to either flag statements as being contrary to fact, or what to do if something turns out to be not the case. Smerdis of Tlön 19:03, 30 May 2006 (UTC)

JA: Whole books have been written on Negation in wider rhetorical and philosophical senses that go far afield from logical negation. And consider: If pseudoscience is false science — is pseudopseudoscience then true science, or does it just get pseuder and pseuder with re*iteration? The mind toggles, the world does not. Jon Awbrey 19:24, 30 May 2006 (UTC)

JA: So where are we on this? I need to continue working on the "16 function" articles. I'll make a Negation (rhetoric), and maybe a Negation (metaphysics) article for all the Hegelians and No-Exitentialists to toy with. Jon Awbrey 04:05, 1 June 2006 (UTC)

Too technical![edit]

This article is all very well, but if someone (like my freshman calculus students, say) wants some help in understanding what negation is, this will leave them more confused. I just added a helpful sentence in the preamble, pointing out that negation is a perfectly natural thing to do and formalizes something we do in everyday language.

This also needs some examples. I'll add some if I have time. Ewjw 07:55, 18 October 2006 (UTC)

Proposed move and re-structure[edit]

I have been working on all of the logical operators recently. I would like to see a consistent format for them. There is a wikiproject proposal for this at: Wikipedia:WikiProject_Council/Proposals#Logical_Operators. Also see Talk:Logical connective.

It looks to me like there has been discussion about this already here. I would like to see the logical, grammatical, mathematical, and computer science applications of all of the operators on the single page for each of those concepts. I'm not sure this is what people had in mind. However, quite frankly I'm thinking any one of them could be a feature article of the day in the making.

Gregbard 05:27, 28 June 2007 (UTC)

I don't think a remerge is needed: the present separation between logical negation and negation more broadly conceived (at present labelled negation and negation (rhetoric)) seems sensible to me. However, I think negation (rhetoric) needs to be expanded, and references given. Dsp13 11:06, 4 July 2007 (UTC)
I hope you will reconsider. I am trying to expand all of the logical operator articles. The concept behind negation and negation (rhetoric) are the same concept. I would like to similarly unite and rearrange articles so that they are all -- you know -- encyclopedic. Please visit the project proposal linked above and leave a comment. If you take a look at how chocked full of potential the nand, or, and and articles are, maybe you will see my point with not. Be well, Gregbard 23:01, 4 July 2007 (UTC)
I suggest not to merge the articles, and to expand Negation (rhetoric). I wrote an article in French about Negation in Linguistics (not quite complete yet) and there are very many things to say, most of them having little to do with Logical Negation, even if there should be links of course. By the way, I quoted the English article as a reference. Thanks for attention. Félix Potuit. 17:06, 16 September 2007 (UTC)
I agree. Negation is a natural language phenomenon that is only echoed symbolically in logic. I have recently written an encyclopedia article in English on "Negation and Negative Polarity". I still own the rights; I've signed no contracts because it was a hurryup job after the original author bailed. So, I hereby place it in the public domain for use in Wikipedia. It's very dense -- they wanted only 1000 words -- and it refers to the monadic negative functor "~ / ˺ / NOT" in predicate calculus, but its focus is on the fact that negation, like quantification and modality, is an operator and thus has a scope implicated in its syntax and semantics, which has a lot of interesting detail, most interestingly negative polarity items. The article should be revised to point to any rhetorical or logical negation items; but it should subsume most of the current [Polarity Item] item, which is very limited in scope and coverage. P.S. I'm not a Wikipedia member and don't want to become one; but I'm willing to contribute. - John Lawler —Preceding unsigned comment added by (talk) 23:07, 8 October 2007 (UTC)
It's only a mere symbolic echo is it? Hmm. You realize that one could look at it the other way with more justification do you not? Negation is based on a principle of logic. A principle is supposed to be true in all possible worlds, while the language phenomenon only exists in a particular historic world as it has unfolded. The concept of logical negation is the more fundamental and general concept being discussed here. An encyclopedia is organized from general to specific so as to eliminate prejudicing the reader to certain interpretations of meaning over other interpretations. One of the goals in logic is to strip away the interpretations and identify what lies behind them as a foundation.
I have proposed that we expand the logical connectives into an encyclopedic series of 16 articles as the center of these concepts. I think there is enough material on each of them to warrant a substantial article.
One of the ways that this could be organized so as to please everyone, is the way that big city articles have, for instance, a main 'Denver' page with several supporting pages such as 'History of Denver', in each case there is a link, and a small paragraph blurb intro. This would not require a merge, but rather a small duplication of material. Be well, Greg Bard 23:35, 8 October 2007 (UTC)

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 04:19, 10 November 2007 (UTC)

Lingo Programming[edit]

Didn't lingo (director) use this symbol? If I may ask. (talk) 17:34, 24 May 2008 (UTC)


The symbol used in the article is new to me; so far, I was certain that negation was symbolized by a tilde (~) - at least two books I have read use this notation. Perhaps we should add a small note that the tilde is sometimes used too? Korodzik (talk) 11:26, 14 September 2008 (UTC)

Isn't ~ for Bitwise NOT in C/C++? The logical NOT would be ! (talk) 12:57, 8 September 2009 (UTC)
I've seen the tilde being used to mean aproximate or aproximatly, as in " a day has ~24 hours" or in some programming language (i don't remember which exactly) combined with the equal sign "~=" to mean aproximatly equal (used with floats, it returns true if the two values are less than a predefined margin of error apart from each other), kinda like how !=, >= and <= came to be. --TiagoTiago (talk) 04:37, 4 January 2011 (UTC)

Minor Semantics Issue?[edit]

Quoth the article: "So, if statement A is true, then ¬A (pronounced "not A") would therefore be false; and conversely, if ¬A is true, then A would be false." I'm not certain, but wouldn't that be the contrapositive, not the converse? --Daniel Draco (talk) 14:22, 5 October 2009 (UTC)

This is weird of course, since it presumes double negation law. Not always valid, depending on the logic. Vlad Patryshev (talk) 06:35, 21 December 2009 (UTC)

The Definition[edit]

Negation is defined here for a two-valued Boolean logic, using some kind of sets. I do not think this definition is general enough. Later in the article you find references to intuitionist logic, where there may be more than two values, and of course no sets. I believe the beginning of this article should be reworked, to be more professional. Vlad Patryshev (talk) 06:35, 21 December 2009 (UTC)


redirects to this article. Does this character have a meaning different to ¬? --Abdull (talk) 17:58, 8 September 2010 (UTC)

The ¬ symbol itself?[edit]

I came to this article looking for information on the "¬" character, not just its meaning, but also things like its origin, name, how people write it when not using a computer, typewritter etc, why it is present in the Abnt2 keyboard layout for AltGr keypresses but isn't seen in most other layouts and so on. Could someone expand this article talking about the ¬ symbol itself, or create it's own article please? --TiagoTiago (talk) 04:30, 4 January 2011 (UTC)


Someone has added comments into this section, with these edits. Unfortunately, I don't feel qualified to clean this up myself. Needs attention from an editor with the right technical knowledge. Thanks. – Wdchk (talk) 04:53, 19 October 2011 (UTC)

No proper Definition[edit]

The definition of Negation in the article is to be true when its operand is false. "FALSE" however is defined as the negation of TRUE, see These definitions are therefore mindlessly circular and meaningless. (talk) 13:43, 28 December 2013 (UTC)

I did a bit of work on this and there is no agreed definition of negation according to F.H. Heinemann 1944. Text added with ref regarding this. (talk) 22:48, 29 December 2013 (UTC)