Talk:Proposition/Archive 2

Archive 1

Archive 2

rename

Renamed article from Proposition to Proposition (philosophy) since title better reflects content--Philogo (talk) 00:47, 19 February 2009 (UTC)

Philogo do you realize that people use those titles to link to. There is no article named "Proposition" and you see a need to tag this thing "philosophy" as if it is some highly technical term. The prevailing use is this one. Please move this to the appropriate place "Proposition" and stop with the parentheses. You are moving this material father away from the reader practically and in principle. ?!?!? Pontiff Greg Bard (talk) 01:04, 19 February 2009 (UTC)

I agree. Please undo what you have done, Philogo. The article is already in the Category Philosophy.Rick Norwood (talk) 15:14, 19 February 2009 (UTC)

Proposition called a claim?

Page currently says

In logic and philosophy, the term proposition (also often simply called a claim)....

I don't think this is right. A proposition may be something that you consider flat false; a claim is usually something that you believe, or at least are assuming for the nonce. --Trovatore (talk) 00:19, 2 September 2009 (UTC)

I am a mathematician who has published in the area of mathematical logic, and I have never heard a proposition called a claim. Rick Norwood (talk) 12:41, 14 October 2009 (UTC)

1) One person calling a proposition a "claim" does not mean that it is "often" called a claim.

2) In "All men are mortal." the subject is "men", not "all men". "All" is a quantifier. A full statement would be "For all x, if x is a man, then x is mortal."

Rick Norwood (talk) 20:59, 29 October 2009 (UTC)

I did provide a reference, Parker and Moore (which is two people btw). These guys wrote a very popular textbook on the subject (which means more than two people agreed since it is in like its tenth edition.) Yes, it is correct for at least two reasons. The meaning of "claim" clearly involves both that it be a statement, and that it be either true or false. The term "claim" redirects to this article. I am not sure what the point of #2 is supposed to be. Is "full statement" some kind of term because it looks like you are making a universal instantiation of a propositional function there.

Furthermore, all critical thinkers call propositions "claims". Pontiff Greg Bard (talk) 21:12, 29 October 2009 (UTC)

Parker and Moore is a wonderful book. It is, however, an attempt to explain logic in natural language to college students. Parker and Moore never say "a proposition is often called a claim", they just use the word "claim" as a common word that is easier for beginning students to understand than "proposition". Everything in that book is aimed at beginning students, and it is not a good reference for an encyclopedia. Rick Norwood (talk) 21:26, 29 October 2009 (UTC)

Insofar as logic and critical thinking and Wikipedia is concerned, it is a RS. Your characterization of the book and Wikipedia are your POV. This is a general reference encyclopedia for a wide readership... this includes non-mathematicians. I think what is happening here is that some people just insist on mathematical jargon to the exception of other terminology used. That's not appropriate for this article, nor Wikipedia. In the interest of people searching that term, please relent. Always include alternate terms. Pontiff Greg Bard (talk) 21:37, 29 October 2009 (UTC)

Propositions are NOT sentences

Why are we defining propositions as sentences, when philosophers have consistently distinguished between sentences as units of language and propositions as what sentences express? I'm not sure I know of any prominent philosopher who thinks propositions just are sentences. Parableman (talk) 12:57, 12 June 2010 (UTC)

I am not sure what's going on, but I am pretty sure that most practising mathematical logicians don't make this kind of distinction. Propositions in the sense you describe aren't of much use as mathematical objects. Some time ago I learned on Wikipedia that some people argue for renaming propositional logic to "sentential logic" based on this philosophical definition lf "proposition". That's the first I ever heard of it. A small number of mathematical textbook authors seem to have followed this proposal, but the majority still use the standard term.

Could it be that the second sentence is intended to explain how philosophical terminology differs from the plain language meaning of "proposition" and the way the term is used in mathematics? Hans Adler 13:14, 12 June 2010 (UTC)

Parableman is right that the article here shouldn't define a proposition as a sentence. But let me explain first what I think is going on. Mathematicians (I am one) don't really use the word "proposition" except in vestigial forms such as "propositional variable" or "Proposition 1.32". However, philosophers have different ideas. They like to distinguish between "sentences" and "propositions", particularly in the (metaphysical) study of truth. From the SEP article "Propositions":

"Propositions are also commonly treated as the meanings or, to use the more standard terminology, the semantic contents of sentences, and so are commonly taken to be central to semantics and the philosophy of language. "

Another nice place to start in the SEP is Correspondence theory of truth:

"Confusingly, there is little agreement as to which entities are properly taken to be primary truthbearers. Nowadays, the main contenders are public language sentences, sentences of the language of thought (sentential mental representations), and propositions. Popular earlier contenders, viz. beliefs, judgments, statements, and assertions have fallen out of favor primarily because of the problem of “logically complex truthbearers”.

The thing that is amazing to mathematicians is that anyone has found it relevant to make a distinction between language-sentences, thought-sentences, propositions, judgments, statements, and assertions. However, if you reflect for a moment about the problems that would arise if you tried to defend a metaphysical theory of truth, it does make sense that these distinctions might be relevant.

Personally, I try to avoid editing these sorts of things, because as a mathematician I think I am not sufficiently sensitive to the area to get it right. However, I dug up the edit that changed the lede to its present form [1]. I think that going back to the previous lede would be an improvement. — Carl (CBM · talk) 14:33, 12 June 2010 (UTC)

I changed it back to the previous lede from the diff I posted. — Carl (CBM · talk) 14:48, 15 June 2010 (UTC)

I have to agree, claiming that propositions are sentences is far from uncontroversial; while it may well be that the distinction is meaningless in mathematics it is certainly a valid and very important area of contention in philosophy, at least in theories of truth. Many different sentences (utterances, what have you) can express the same proposition -- I have never heard anyone claim that they are the same entity, and even if a source could be produced attesting to this equivalence it certainly shouldn't be presented in the lede as if it were the only possibility. BrideOfKripkenstein (talk) 23:12, 15 June 2010 (UTC)

The article Truthbearer explores the various usages of the terms sentence, proposition statement &c. and sets out the various philosophical issues involved. As the article Truthbearer says Many authors use the term proposition as truthbearers. There is no single definition or usage. Sometimes it is used to mean a meaningful declarative sentence itself; sometimes it is used to mean the meaning of a meaningful declarative sentence. This provides two possible definitions for the purposes of discussion as below (wherein mds is written as shorthand for meaningful declarative sentence).Philogo (talk) 15:29, 14 November 2010 (UTC)

References

If I'm understanding him correctly, User:Gregbard has elsewhere conceded that propositions are not sentences; nonetheless I would offer the following two sources I was able to find right off the bat that support my contention (that propositions are not uncontroversially assimilated to sentences, either sentence types or sentence tokens):

• Soames, Scott (1999). Understanding truth. New York: Oxford University Press. pp. 13–19. ISBN 0-19-512335-2.
• Lycan, William G. (2000). Philosophy of language: a contemporary introduction. London: Routledge. pp. 80–87. ISBN 0-415-17116-4.

And, not to flagellate a deceased equine, I concur with User:CBM above. BrideOfKripkenstein (talk) 18:56, 16 June 2010 (UTC)

I think it's nonetheless fairly common to define propositions are either sentences or something like the meaning of sentences. While there is undoubtedly some philosophical debate on this, I find that introductory logic and critical thinking texts usually define propositions as sentences and texts which are somewhat more philosophically sophisticated go for the meaning definition (or something similar). I really don't think that this issue should bother us too much in the lede. I'd be happy if readers came away with an introduction to the subject similar to that found in elementary texts. Phiwum (talk) 02:39, 17 June 2010 (UTC)

And again, some quotations that might be of help:  User:Morton Shumway/Proposition (Quotes) --Morton Shumway (talk) 11:35, 3 August 2010 (UTC).

Related Concepts

Under thus section the article says 'Facts are verifiable information.' I have not see this definition before and a citation would improve the article, but I doubt if it is the only account of the concept of 'fact' (see eg/ http://plato.stanford.edu/entries/facts/) Philogo (talk) 19:07, 30 November 2010 (UTC)so the article should say perhaps 'Some authors says that Facts are verifiable' information.Philogo (talk) 19:02, 30 November 2010 (UTC)

Section is too confusing, self-contradictory and off-topic to be useful therefore deleting — Philogos (talk) 01:47, 13 October 2014 (UTC)

Anyone working on this?

Is anyone actively editing this page? I notice several things that I think should be changed, so if someone else is working on it, it might be easier to coordinate or plan changes. Also, I am fairly familiar with mathematical logic, linguistics, and, to a lesser extent, philosophy of language, but I am not familiar with how propositions are treated in philosophy generally. So if there is a philosopher around, I could use some help in that area.

For starters, I think it would be helpful to either focus the article on things that can be assigned truth-values or else institute at the beginning a distinction between the syntactic and semantic concepts relating to propositions. Other uses can be handled by pointing to the disambiguation page (or such). Perhaps an outline of the linguistic objects and distinctions associated with propositions would also be helpful.

In the meantime, the following paragraph jumps out as particularly bad:

In mathematical logic, propositions, also called "propositional formulas" or "statement forms", are statements that do not contain quantifiers. They are composed of well-formed formulas consisting entirely of atomic formulas, the five logical connectives, and symbols of grouping (parentheses etc.). Propositional logic is one of the few areas of mathematics that is totally solved, in the sense that it has been proven internally consistent, every theorem is true, and every true statement can be proved.[2] (From this fact, and Gödel's Theorem, it is easy to see that propositional logic is not sufficient to construct the set of integers.) The most common extension of propositional logic is called predicate logic, which adds variables and quantifiers.

I don't recall seeing the term "proposition" used often in mathematical logic, only perhaps in introductions to logic aimed at non-mathematicians. Instead, I see terms like "string", "formula", "well-formed formula", "expression", and "sentence" for the syntactic notions, and for semantic notions, "interpretation" or "value" of some kind. (I have, though, seen "atomic formula" defined to include some strings with quantifiers.) Also, propositional logic (including its atomic formulas) is also called sentential or statement logic. Since there are objects in predicate logics that can be assigned truth-values, this whole section seems misleading in the context of the article. Anyway, since usage isn't consistent across authors, more explanation seems in order. Also, there are not only five logical connectives (think not only of the Sheffer strokes but all other n-ary connectives). The "totally solved" remark is bad for many reasons. The reference to Gödel's first incompleteness theorem seems irrelevant besides being poorly stated. The last comment also seems unmotivated, but at least "extension" should be clarified (it has specific meanings in logic and model theory), and predicate logic adds predicate and function symbols in addition to quantifiers and variables.

Cheers, Honestrosewater (talk) 09:12, 15 January 2012 (UTC)

The section you quote as particularly bad is based on Hamilton's Logic for Mathematicians. Of course, there are other ways of developing symbolic logic and other terms used. Improvement is always welcome, especially from people who are active researchers in this area. Rick Norwood (talk) 13:57, 15 January 2012 (UTC)

Well, I can see it being clearer in context. I can add some to the logic and linguistic aspects, but I wouldn't know where to begin with the philosophy stuff. Some of the claims seem suspicious, though. For example,

The existence of propositions in sense (a) above, as well as the existence of "meanings", is disputed by some philosophers

What philosopher -- serious, professional philosopher -- disputes the existence of meanings? Unless they are using some uncommon meaning of "meaning", it doesn't seem tenable. How would such a person explain language use? Perhaps what was meant is that philosophers dispute particular theories of meaning, reference, and such, e.g., Fregean senses.? Cheers, Honestrosewater (talk) 14:57, 15 January 2012 (UTC)

I added a bit to the Logic section and deleted the references to consistency and completeness. I'd appreciate any feedback so I know if or how to continue. Cheers, Honestrosewater (talk) 19:04, 15 January 2012 (UTC)

There is a very good article in the January 2012 issue of the Notices by Frank Quinn about the different understanding of "truth" in mathematics and in philosophy. I don't know if any part of it applies here, though. Rick Norwood (talk) 20:39, 15 January 2012 (UTC)

I hate to say it, Honestrosewater, but I think now you have gone into much more detail than this article needs. For example, the idea that a proposition can be viewed as a string of symbols is important, but a catalog of the kinds of symbols that can be used (variables, quantifiers, etc.) is too much to go into at this level. I think what the reader needs to know in this article is that the word "proposition" is often used in mathematical logic, that it is sometimes distinguished from the word "predicate", and that it is assumed to have a truth value. In other words, I found the previous version not too short, but too long.

I also note that the paragraph on Logical Positivism, which has been part of the article for a long time, doen't make beans for sense. What is the truth value of a STOP sign?

And it occurs to me that the article should mention "The King and I".

Rick Norwood (talk) 21:17, 15 January 2012 (UTC)

Yes, I agree with you mostly about the level of detail. I had more detail about symbols originally but trimmed it down. I could perhaps trim more. The point was mainly to show that propositions, as syntactic objects, can be built up in different ways, and this affects what propositions, as semantic objects, can be expressed or proven in the system or something along those lines. I don't think these distinctions have been made quite clear enough yet, though.

Quinn's article so far is amusing and right, I think. I can't stand most philosophy, and most people hate math. :^) It's interesting because I am doing an independent study in nonstandard analysis this semester and so have been reading and thinking about this period in mathematical logic (~1850-1931), model theory, and the back-and-forth between intuition and formalism. It ended up being a strange (and nonconstructive) formalism from math logic and model theory (nonstandard models via compactness, nonprincipal ultrafilters, and such) that allowed an infinitesimal approach to reemerge (and Leibniz himself anticipated (and hoped for) much of the formalization). Anywho... good stuff.

I notice that you guys seemed to want to make this article mainly about philosophy? But the articles that Philogo mentions, declarative sentences in linguistics and statement and sentence in logic, are not about the same thing. In linguistics, you have an even more complicated situation because, in addition to the more complicated language, you have to also consider pragmatics. Consider "A couple was hit by a bus. The driver called for help." The second sentence expresses the proposition (grant, for argument) that the driver of the bus called for help. Or the discourse as a whole conveys this, at least. But neither sentence expresses this explicitly. It is an inference that the hearer is expected to and does make (called a bridging inference). In a similar vein, "Q: Did you finish your homework? A: I finished most of it." conveys that not all of the homework was finished, though this is not explicitly stated (this is a scalar implicature). There are many more things to untangle: utterance, locutionary act, physical signal, linguistic signal, conceptual signal, sentence, statement, propositional content, assertion and other illocutionary acts, meaning, intended (speaker) meaning, received/inferred (hearer) meaning, truth-functional/semantic meaning, pragmatic meaning, inference, presupposition, implicature, ambiguity, reported speech, etc. It's rather hairy. :^|

I think the linked SEP article starts in a good way, by noting the many meanings of the term. Would it be a bad idea to try to organize this article by how the different fields that address propositions (logic, linguistics, philosophy) deal with it, perhaps with some indication of the scope of meanings given in the intro? The historical usage section now only includes philosophical uses, so this could be a start to the philosophy section. The logic section also is started. I can start a linguistics section.

Perhaps a better option would be to organize by the different meanings or relationships of the term. E.g., how propositions are related to speech acts, to formulas in formal languages, to truth-values, sentences, mental states, etc. Then the approaches, if any, of different fields can be treated in the appropriate section.

I do not know how traffic signs are true or false, though. I suppose it depends on the type of sign. (We could add a bit about semiotics, the more general theory of signs (in a technical sense of the word).) A stop sign has more of a directive meaning, I think, as I presume you meant; it tells you to do something. Something like a street sign (with the name of a street) could maybe be interpreted as asserting that some street has some name or perhaps it is declarative in that the sign actually makes a street have a name by virtue of its being there. It is perhaps more important to explain the issues than to pronounce verdicts anyway. People can interpret things in different ways, so it's hard (maybe impossible?) to find perfect consensus, though some overlap of interpretations must exist for the system to work.

I have to plead ignorance about The King and I.

Cheers, Rachel / Honestrosewater (talk) 22:47, 15 January 2012 (UTC)

The King and I is a Broadway musical in which the King of Siam begins many of his speeches with the word, "Proposition". Rick Norwood (talk) 23:54, 15 January 2012 (UTC)

Merge "Statement (logic)" proposal

I am proposing that the article Statement (logic) be merged here to "Proposition". This is a continuation of the suggestion at Talk:Statement_(logic)#Merge_with_proposition.3F. Generally speaking — although I'd guess some particular authors differentiate (although probably also inconsistently) — I believe that "statements" and "propositions" are synonymous and are used interchangeably. The "Statement (logic)" article is short and less-well developed, hence it seems to make better sense to merge here (even though I have a slight personal preference for "statement"). If you believe there are separate concepts, please detail as succinctly and accurately as possible what you believe the difference is (preferably with some sources). Jason Quinn (talk) 22:20, 12 February 2013 (UTC)

From the other discussion, User:Gregbard has raised concern about what this means for categories using the names. I have responded briefly about that at the old discussion. Jason Quinn (talk) 22:38, 12 February 2013 (UTC)

"Proposition" is the older usage, "statement" the more recent, but in most mathematical contexts they are synonyms, and we don't need two articles. Rick Norwood (talk) 22:55, 12 February 2013 (UTC)

From a mathematical point of view these are just synonyms, although some people might want to permit general truth values for statements and reserve the term proposition for statements that are always true or false. In philosophy there are, as usual, no uniform definitions. The meanings still seem to significantly overlap there, as in mathematics with a tendency for statement to be the slightly more general term.

I think it's very sensible if not inevitable to discuss the two terms together in one article. For those authors who treat them as synonyms this is a necessity. For those who define both differently, the meaning of both terms will be much clearer if we define them together. This seems to be the only way to prevent major confusion on these terms. Hans Adler 23:22, 12 February 2013 (UTC)

Regarding Category:Statement and Category:Proposition: I agree that they clearly have different flavours. I see no reason why they should immediately be merged just because we merge the articles. In fact, they could just stay as they are; otherwise one or both should be renamed. Unless someone wants closure before the article merge, I think this can be discussed later. (I doubt that I will participate in a discussion on the categories.) Hans Adler 23:29, 12 February 2013 (UTC)

I think it is sensible to merge these two subjects. One practicle reasons is that meta-connections are scattered with some connecting to 'proposition' the other to 'statement (logic)'. I sense that most people would agree to merge these two and discuss the difference (if there is) on the same page. — Preceding unsigned comment added by Timelezz (talk • contribs) 12:35, 8 December 2013 (UTC)

To understand whether these are really two sides of the same coin. A Statement like "I want strawberries", is a Proposition as well? Timelezz (talk) 16:26, 18 December 2013 (UTC)

The distinction is important in philosophy and theoretical linguistics. Consider that, in most cases, many statements express the same proposition (the same underlyimg idea). I.e. there are usually several ways to say the same thing. I can not stress enough how useful the distinction is. — Preceding unsigned comment added by DPhil2002 (talk • contribs) 13:29, 20 May 2014 (UTC)

There is a very important distinction between propositions and statements. Propositions admit multiple representations. Statements are their representations. Consider a mathematical and linguistic example:

Take the statements '2/2=1' and '2*(1/2)=1'. Both statements express the same proposition. Take the statements 'All cats are mammals' and its contrapositive 'No cats are non-mammals'. Both statements express the same proposition.

If propositions are statements then '2/2=1' and '2*(1/2)=1 are two propositions that express the same proposition (or two statements that express the same statement).

Merging statement and proposition is just a bad idea. I suggest this discussion be closed. 174.91.34.251 (talk) 13:48, 2 October 2014 (UTC) MikeZhao

I think you're taking "statement" to mean "sentence". That is indeed one possible usage of the word, but I do not believe it is the majority one. If the merge happens, there will need ot be a hatnote at the top referencing this other sense. --Trovatore (talk) 16:58, 2 October 2014 (UTC)

Opposed to merge. As is clear from the articles statements and propositions are distinct concepts of truth-bearers justifying distinct articles.— Philogos (talk) 01:02, 20 October 2014 (UTC)