Talk:Non-classical logic

Failed Merge of Non-Aristotelian logic article
Back in 2015, Aisiantonas claimed to have merged the now non-existing article Non-Aristotelian logic into this one. Unfortunately, if we review the newest pre-merge version of that article:

https://en.wikipedia.org/w/index.php?title=Non-Aristotelian_logic&oldid=676012595

We find that he in fact failed to perform a proper merger, and a lot of details about non-classical logic independent of the apparently back then existing controversy about General Semantics got lost as a consequence. This seems bad, and Someone™ should do a proper merge. I lack the time to do so unfortunately. &mdash; No identd (talk) 12:17, 16 November 2017 (UTC)

csd
I removed a csd template asking to move deviant logic here. That article is not about non-classical logic in general, and so it would not be appropriate to move it here. Indeed, deviant logic appears to be a neologism of a particular author, while "non-classical logic" is a well-established term. &mdash; Carl (CBM · talk) 01:52, 7 October 2009 (UTC)


 * I am looking for a way to make a destination for those clicking on the awkward "non-Classical logic" link on the logic template. Currently there is no content for such an article. There is a category Category:Non-classical logic without a main article. The content can be revised appropriately so as to work just fine. The idea here is that the content of "deviant logic" moves to the "non-classical logic" and the title deviant logic redirects to non classical, If you believe it is a neologism (and it just seems that anything unfamiliar to you and Arthur is a neologism?!?) than what is your objection to moving it. It is also consistent with the Sider book I pointed you towards (i.e. an accepted term, not a neologism). Would you prefer I make the link on the template to deviant logic? That doesn't make sense if you think it is a neologism. You should instead favor the plan I have set out I would think. Be well, Pontiff Greg Bard (talk) 02:06, 7 October 2009 (UTC)


 * I cannot find the word "deviant" in Sider's book with by PDF reader's search function. Can you tell me where you found it?


 * I also looked at Google books for "deviant logic", where I gained the impression that the term is tied very tightly to Haack.


 * If one wanted to write an article on non-classical logic in general, that could go here. But at the moment there is not even enough content in the section on non-classical logic in the article classical logic to stand alone apart from a stub, and the article about deviant logic is also tied very closely to Haack's book rather than to non-classical logic in general. &mdash; Carl (CBM · talk) 02:25, 7 October 2009 (UTC)


 * Sider's chapter 1.7 is titled "Extensions, deviations, variations." This is the subject matter I am talking about. "Deviant" logic is just a type of non-classical logic, so they aren't totally synonymous, but the content could certainly go in an article titled "non-classical logic." Which I think would be a good start. Pontiff Greg Bard (talk) 02:32, 7 October 2009 (UTC)


 * So Sider's book does not actually use the term "deviant logic", and does not say that "deviant logic" is a synonym for "non-classical logic"?
 * I believe that "deviant logics" are actually a subset of non-classical logics. As I said, one could write an article on non-classical logic in general, but at the moment we have no such article, so the section on non-classical logics in the article classical logic is the best target for this page while it remains a redirect. &mdash; Carl (CBM · talk) 02:37, 7 October 2009 (UTC)


 * No it does not use the term "deviant logic" it has a chapter that talks about deviations, and the subject matter is the same as what is being talked about in deviant logic. This appears to be very-very nit-picky at this point.-GB


 * I agree. However I think the easiest thing to do is move the content, and make it a section called "deviant logic" or "deviations", etcetera. I think I just take a more eventual approach than you Carl. Pontiff Greg Bard (talk) 02:47, 7 October 2009 (UTC)


 * Please do not insert text in the middle of my posts. Which chapter of Sider is on the subject of deviations? I have the table of contents in front of me. &mdash; Carl (CBM · talk) 02:50, 7 October 2009 (UTC)


 * Sorry 'bout that, I was just trying to respond to the immediately previous content. I'll refrain f.n.o. The chapter is 1.7. Pontiff Greg Bard (talk) 03:16, 7 October 2009 (UTC)


 * That's a section; it would be an exaggeration to say that Sider devotes a chapter to the issue of deviations from classical logic. The reason to worry about whether Sider actually says "deviant logic" is to see whether he gives a definition of that literal term.


 * Also, that section refers to changes from "standard" logic, not "classical" logic. There are, for example, classical modal logics, which would not qualify as "non-classical" even if they are extensions of whatever Sider calls "standard" logic. It is far from obvious that Sider is talking about non-classical logics at all. &mdash; Carl (CBM · talk) 03:43, 7 October 2009 (UTC)


 * Yeah, non-obvious. Did I say chapter? What's the diff Carl? Say listen, clearly it would have been easier to just move the content like I originally proposed, and settle these issues in time. Anyway, I have expanded the article somewhat. Pretty much done for the day. Pontiff Greg Bard (talk) 03:52, 7 October 2009 (UTC)


 * See your post dated 02:47, 7 October 2009. It still appears incorrect, looking at google books and at Sider's book, that "deviant logic" is a synonym for "non-classical logic". So moving the content from the former here would be strange. You might notice that section 1.7 of Sider's book does not use the word "classical" at all, presumably because that is not what he means. As I said, "classical modal logic" is well established; check google books or for example. You have to watch out, though, because some people have a different meaning for classical modal logic as in the article here. I simply mean modal logic with semantics in which every sentence is either true or false in a particular model. &mdash; Carl (CBM · talk) 03:56, 7 October 2009 (UTC)

deviant/extension vs. non-classical
There seems indeed to be a taxonomy along the lines of deviant (or deviation) vs. extension that is accepted beyond Haack these days, but not very widespread. There are some additional sources:  (2nd link is more detailed; funny we have L. T. F. Gamut). Tijfo098 (talk) 00:23, 11 April 2011 (UTC)

What is strange is that although van Benthem is a fairly prolific author, he doesn't seem to use this taxonomy in more recent works. Tijfo098 (talk) 01:15, 11 April 2011 (UTC)

A bit more secondary coverage:  (has details on par with "Gamut"). Tijfo098 (talk) 05:31, 11 April 2011 (UTC)

Hegelian Logic addition?
is there a reason why Hegel's logic doesn't fit in this category? it seems like he fits squarely in the extension of classical logic category, unless I'm missing something obvious. 210.204.130.224 (talk) 12:39, 30 August 2021 (UTC)

Classical vs. non-classical modal logic
See this discussion: is this article's description of modal logic inaccurate? Jarble (talk) 15:36, 2 March 2024 (UTC)