Talk:Term logic

Deleted for ridiculosity

I deleted the following text: "In a similar vein the extremely complex symbolic logic that developed in the 20th century and its formal strictness can sometimes mislead students by giving them the impression that there is something "truer" about it because its machinery is complex; however, it in fact lacks truth and processes lies and falsehoods equally. It may turn out in fact to be another form of systematised modernism."

Term logic "process lies and falsehoods" equally in just the same way that predicate logic does. I can take the contrapositive of "All skunks are reptiles." I can find this argument to be valid: "All computers are organic things, all organic things are transparent, therefore all computers are transparent." —Preceding unsigned comment added by 68.57.240.77 (talk) 13:59, 13 March 2010 (UTC)

Dead Link

The Link to the lecture notes of Terence Parson is dead. There are, however, other lecture notes on his wegpage (bottom of http://admin.cdh.ucla.edu/facwebpage.php?par=91) which might replace the old ones. I'm not sure which ones to chose but I didn't want to finally remove the link either. May someone with a better knowledge on logic have a look at it? 134.155.84.12 09:54, 11 September 2007 (UTC)

Syllogistic vs. term logic

From Aristotelian logic we have:

Aristotelian logic, also known as syllogistic, is the particular type of logic created by Aristotle, primarily in his works Prior Analytics and De Interpretatione. It later developed into what became known as traditional logic or Term Logic.

and on this page we have:

Traditional logic, also known as term logic, is a loose term for the logical tradition that originated with Aristotle and survived broadly unchanged until the advent of modern predicate logic in the late nineteenth century.

There is a bit of a disagreement between the two pages: the former suggests that there is a difference between syllogistic and term logic, the latter suggests the former is part of the latter. We should not have this inconsistency. Does anyone know what the origin of "term logic" is? It's my impression that Fred Sommers was first to start using the phrase term logic, but his student, George Engelbretsen, uses the two terms apparently interchangeably. ---- Charles Stewart 13:55, 24 Aug 2004 (UTC)

From the article

Following to do list pulled out of the article:

To do: Predicables, Influence on philosophy: to include "existence as a predicate", the Kantian categories, and the petitio principii problem, Explanation of "reduction per impossibile"

I think Talk is a better place for this. — mark ✎ 13:29, 2 Mar 2005 (UTC)

Following tutorial-style section moved out of the article (was a sub-section of 'The Syllogism'):

Examples

Let's try to write a syllogism of the first figure, of the mood EAE (known as "Celarent") . This must have the first premise beginning "no", the second beginning "all" and the conclusion beginning "no". And it must have a major term (P), let's say "vegetarians", a middle term, say "cats", and a minor term, say "domestic felines". The order of terms for the premises in first figure (see table above) is

M-P

S-M

which we rewrite replacing the major term P by "vegetarians", the middle term "M" by "cats", and the minor term S by "domestic felines".

No cats are vegetarians

All domestic felines are cats

Finally, the conclusion must consist of the minor term followed by the major term. This gives

No domestic felines are vegetarians

But note the logic we were following was strictly based on the rules above. You didn’t have to think what the premises were saying at all. It could have been a syllogism in a foreign language, you still could have reached the conclusion by following the rules. Now, as an exercise, read the premises, think what they mean, and try to think what that implies. No cats are vegetarians. None of these things we are thinking about, eat vegetables. But all domestic felines are wholly included in these things, cats. So none of those domestic felines can eat vegetables either. But wait, that's the conclusion we reached by the other method. And it seemed so natural. Perhaps that's why Aristotle thought the syllogism (and particularly the first figure), was so natural. It's a mechnical rule-based process, yet something deeply embedded, in a way that seems quite un-rule-like, in our heads.

As an amusement: write a program to make syllogisms from random terms, moods and figures. Hint: only use common nouns in the plural, as adjectives are harder to convert into the traditional term structure.

This is not Wikibooks. The section might need to be rewritten, or might be left out entirely. If kept, it might need to be moved to Syllogism. — mark ✎ 14:25, 2 Mar 2005 (UTC)

Redundancy

In Talk:Aristotelian logic I've suggested that we have too many articles on Aristotle's logic. --- Charles Stewart 19:40, 9 Jun 2005 (UTC)

Proposal to merge

I'm proposing merging the article Aristotelian logic into this one. See Talk:Aristotelian logic for more info. --- Charles Stewart 19:42, 26 September 2005 (UTC)

Term logic/Danielsavoiu's summary

I'm mostly done with the merge, with the summary of Aristotelian syllogistic that User:Danielsavoiu posted excepted, which I have put in the above subpage of this one. It's less comprehensive than the one we have, but I think it will be rather easier for the newcomer to read. I'm not sure what best to do with it, but it is perhaps best if we make this the first section getting to grips with the system, and turn the existing treatment into supporting discursions into significant topics. Thoughts? --- Charles Stewart 19:09, 12 October 2005 (UTC)

I made some additions recently over on the syllogism page, before looking over this page closely. I suspect all three of the pages need to be merged together. I'm willing to do it myself, but it seems you took a headstart on this project. how should we coordinate on this? Ted 07:01, 21 January 2006 (UTC)

okie dokie

I've gone ahead and integrated the Term Logic page and Syllogism page. Hopefully the integration meets with the approval of everyone; if not, go ahead and revert, and we can discuss it here. Ted 04:21, 5 February 2006 (UTC)

You might like to add a reference to Peter Geach's 'History Of The Corruptions Of Logic' in his Logic Matters (Blackwell 1972), pp.44-61.

Rosa L. 05/05/06

mnemonics

I came here looking for an explanation of the consonants in the mnemonic words for syllogisms, and apparently that text no longer exists on this page or Syllogism. I was able to get some information from historical versions of this page but it seems like it should be on an active page. Also in the Decline section, this article says: "Term logic cannot, for example, explain the inference from "every car is a vehicle", to "every owner of a car is an owner of an vehicle ", which is elementary in predicate logic." Isn't this just an oblique proposition? Gimmetrow 20:54, 15 May 2006 (UTC)

Predicate Logic too hard?

The article says A 100 years ago, school children were taught a usable form of formal logic. The predicate logic that took its place is too difficult to teach in schools. Hence today, – the information age – notwithstanding, children learn no logic whatsoever. Predicate logic is a technical subject studied only philosophers (and a few mathematicians) in universities.

Without evidence, this isn't an NPOV statement? Where is the evidence that predicate logic is too hard? It pretty common in computer science; the logic language Prolog is built on a first order predicate calculus, so it must not be that hard.

Prolog is not taught to school-children. In the US, at least, the term "school-children" is understood to refer to the students in primary school, and certainly not to high-school or college students, where young adults first encounter predicate logic. At a deeper level, I agree -- there is a mountain of math that could be taught at the primary-school level. However, there is a wide-spread failure to do so; I presume because the teachers and administrators themselves don't know the material or how to teach it. linas (talk) 14:57, 8 May 2008 (UTC)

This passage has since been removed. -- Beland (talk) 00:28, 1 December 2017 (UTC)

Revival of Term Logic in the context of AI

From actually referring to Aristotelean logic as in Pei Wang's Return to Term Logic, to logics which simply have proposition-denoting terms like in SNePS, term logic is not forgotten.

Could someone update the article to take account of this? Perhaps the second use of the term (a logic with proposition denoting terms) should be disambiguated?

No. I have reviewed literally hundreds of AI architectures and representational systems (and have spent hundreds of hours representing knowledge in SNePS or hacking its source), and outside of toy problems (say, the Tower of Hanoi), finite-state automata (which are called "artificial intelligence" in computer games and at MIT circa 1990), and ELIZA (which could be implemented with regular expressions), AI never uses a logic as weak as term logic. It has far too little representational or computational power. It would be like trying to do arithmetic with the integers "one, two, and many". You can't even represent the vast majority of simple English sentences: "John loves Mary" is beyond the representational power of term logic.

One key difference is that term logic has only unary propositions. You need binary propositions to be able to express questions that are undecidable. Some AI systems try to avoid undecidability, but my guess is that term logic only has the computational power of regular expressions.Philgoetz (talk) 03:24, 17 November 2019 (UTC)

Origin of "A, E, I, O"

Hey, you guys seem to have a statement in the article that says that the origin of the letters 'A, E, I, O' --as referring to the four types of logical propositions-is discussed in this article (bottom of section titled "The basics"), but nowhere can I find a part where said terms are explained. Perhaps it was deleted in a previous edit or revert?

If you said text never existed, perhaps someone would be willing to at least link to where said terms are explained?

Excantiaris (talk) 03:49, 2 October 2008 (UTC)

Move proposal

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

No consensus to move. Vegaswikian (talk) 06:35, 22 February 2012 (UTC)

Term logic → Aristotelian logic – Greg Bard (talk) 04:42, 15 February 2012 (UTC)

• ? What is the rationale for the move? WP:COMMONNAME? Consensus decision reached among logicians at WP:PHILO? Personal preference? There's also the option of "traditional logic". Note that Aristotelian logic formerly was an independent article but was merged into this one. Good Ol’factory ^(talk) 00:28, 16 February 2012 (UTC)
• Tentative oppose. Until a rationale is provided, I am tentatively opposing, simply because I get more straight-up g-hits for "term logic" than I do for "Aristolelian logic". But of course I could change my mind if a rationale or explanation were provided or if a more rigorous analysis of what the most common name is were provided. Good Ol’factory ^(talk) 01:09, 21 February 2012 (UTC)

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

“‘No men are immortals’ is negative”

But there's a double negative! No and im- are both negatives. If we combine two negatives, do we get a positive or are we still left with the negative? In this particular case, they cancel each other out. There are exceptions in the English language (e.g., “no nothin'”), but here the apparently negative sentence “No men are immortals” has the same meaning as the positive sentence “All men are mortals.” EIN (talk) 09:52, 24 October 2012 (UTC)

I'm probably engaging in plain sophistry right now. Don't give this too much thought. EIN (talk) 16:31, 25 October 2012 (UTC)

No, you're right:

• A-type: Universal and affirmative or ("All men are mortal")
• I-type: Particular and affirmative ("Some men are philosophers")
• E-type: Universal and negative ("No men are immortal")
• O-type: Particular and negative ("Some men are not philosophers").

The current text was changed from "No philosophers are rich"... Better examples of the "traditional" square would be:

• A-type: Universal and affirmative ("Every philosopher is mortal")
• I-type: Particular and affirmative ("Some philosopher is mortal")
• E-type: Universal and negative ("Every philosopher is immortal")
• O-type: Particular and negative ("Some philosopher is immortal")

However, the received version lacks existential import, whereas Aristotle's original doesn't have that defect:

I call an affirmation and a negation contradictory opposites when what one signifies universally the other signifies not universally, e.g. every man is white—not every man is white, no man is white—some man is white. But I call the universal affirmation and the universal negation contrary opposites, e.g. every man is just—no man is just. So these cannot be true together, but their opposites may both be true with respect to the same thing, e.g. not every man is white—some man is white.

— Aristotle, De Interpretatione VI–VII 17b

And the examples would be...

• A-type: Universal and affirmative ("Every philosopher is mortal")
• I-type: Particular and affirmative ("Some philosopher is mortal")
• E-type: Universal and negative ("Not every philosopher is mortal")
• O-type: Particular and negative ("No philosopher is mortal")

According to the SEP: [The principle of obversion] states that you can change a proposition from affirmative to negative, or vice versa, if you change the predicate term from finite to infinite (or infinite to finite). Some examples are:

Every ''S'' is ''P''	=	No ''S'' is non-''P''
No ''S'' is ''P''	=	Every ''S'' is non-''P''
Some ''S'' is ''P''	=	Some ''S'' is not non-''P''
Some ''S'' is not ''P''	=	Some ''S'' is non-''P''

Parsons, Terence (2012). "The Traditional Square of Opposition". In Edward N. Zalta (ed.). The Stanford Encyclopedia of Philosophy (Fall 2012 ed.). 4. The Principles of Contraposition and Obversion.

—Machine Elf ¹⁷³⁵ 00:12, 26 October 2012 (UTC)

Syntax

Isn't it more appropriate to use the quantifier 'are' in place of 'every', and the copula 'are' instead of 'is'? It may make no difference to someone who understands the topic, but it leads to awkward sentences which could confuse people not familiar with the topic.

A-type: Universal and affirmative ("Every philosopher is mortal") I-type: Particular and affirmative ("Some philosopher is mortal") E-type: Universal and negative ("Not every philosopher is mortal") O-type: Particular and negative ("No philosopher is mortal")

All philosophers are mortal/ Some philosophers are mortal/ Some philosophers are not mortal/ No philosophers are mortal/

the copula "is" is singular, which does not fit the statements. All and No are obviously plural, and in a syllogism the quantifier 'some' means "One or more," or "at least one." Now, if A, I, E and O statements are all plural, then why use a singular copula? It's more appropriate to format the questions using 'all' in place of 'every', and 'are'/'are not' in place of 'is'.

Say we have the sentence "Jack doesn't know anything about chemistry, and if you don't don't know anything about chemistry then you can't pass a chemistry test, so Jack can't pass a chemistry test."

|All| persons who are like Jack |are| persons who don't know anything about chemistry. |All| persons who don't know anything about chemistry |are| persons who can't pass a chemistry test. |All| persons who are like Jack |are| persons who can't pass a chemistry test.

|Every| person who is like Jack |is| a person who doesn't know anything about chemistry. |Every| a person who doesn't know anything about chemistry...

Wait, that doesn't seem grammatically correct at all.

Basically I'm just saying that it doesn't really matter as far as meaning goes, but if we want to avoid raising some eyebrows from English majors, it's best to not use |Every| and |is|. This point is probably quite trivial or maybe there's a reason I'm not getting as to why it's formatted that way. I just wanted to make the concern noted.

"So, some A is B" "So, some A are B" — Preceding unsigned comment added by 50.135.224.106 (talk) 01:11, 17 December 2012 (UTC)

Difference from predicate logic

What is the difference between term logic and predicate logic? It seems like that should be explained in the article, given that it's saying one replaced the other. -- Beland (talk) 00:29, 1 December 2017 (UTC)

Propositions

These two sentences are contradictory:

1. Thus every philosopher is mortal is affirmative, since the mortality of philosophers is affirmed universally, whereas no philosopher is mortal is negative by denying such mortality in particular.
2. The quantity of a proposition is whether it is universal (the predicate is affirmed or denied of all subjects or of "the whole") or particular (the predicate is affirmed or denied of some subject or a "part" thereof)

"No philosopher is mortal" denies the predicate "mortal" of all subjects. Sentence 1 says it is particular; sentence 2 says it is universal. Which is it? Philgoetz (talk) 03:29, 17 November 2019 (UTC)