Talk:Logical argument

The distinction between argument and explanation seems superficial to me. The page seems to imply that any defense of the idea that "the moon causes the tides" is an explanation, precisely because the fact that there are tides is universally accepted. But could I not conjure up appropriate premises, and then make an argument whose conclusion would be "the moon causes the tides"?

Is this really a distinction make by philosophers and/or logicians these days? If so, could we put some references to their names?

If not, perhaps we could eliminate this section, or make it a lot more clear?

--Ryguasu

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I agree. This is nonsensical. --The Cunctator

Contents

1 Semantics of logic 1.1 Stanford Enc. article 2 Empty section headings 3 Other meanings of Argumentation 4 New introductory sentence 5 RV 20040302's edit 6 Soundness and validity 6.1 Disagreement between Charles Stewart and 20040302 6.2 Resolving the (informal) dispute 7 New lead paragraphs? New version of article? 8 Validity 9 Validity and soundness redux 10 el stupido

Semantics of logic

One of the original contributors to this trend is the philosopher Chaim Perelman, who together with Lucie Olbrechts-Tyteca, introduced the French term La nouvelle rhetorique in 1958 to describe an approach to argument which is not reduced to application of formal rules of inference

The idea that logic is best understood in terms of potential dialogs between opposing positions in an argument predates this idea and can be formalised: Lorenzen was the first to do so. See Game semantics for a currently not very polished introduction to the idea. The idea is anti-Tarskian (hence anti- "semantic theory of truth"), but is itself an idea about the semantics of logic ---- Charles Stewart 13:04, 30 Aug 2004 (UTC)

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That the idea is ant-tarskian is clear. However, I don't agree that this is the same as game semantics. I'll be a little more detailed later on.CSTAR 13:19, 30 Aug 2004 (UTC)

I didn't claim the idea is the same as game semantics; it is obviously is given in a very different spirit. Instead, I claimed the ideas have a common root, namely the idea that logic is dialectical or adversarial in nature ---- Charles Stewart 13:36, 30 Aug 2004 (UTC)

OK. BTW, I am generally concerned with relating the idea of political argument and economic argument into an article about logical argument. Something needs to said, but I myself am troubled by what I wrote down... to use Wikipedia's terminology, the article does seem POV. But what are the options? The article should say something practical about logical argument and about the structure of argument in general. Merely listing historical facts about theories of argument wouldn't be very helpful. This is a dilemma confronting anybody writing an NPOV article.

Maybe the task is too overwhelming.CSTAR 14:17, 30 Aug 2004 (UTC)

Trying to consolidate and make the articles more fluid --DennisDaniels 19:24, 31 Aug 2004 (UTC)

I'm not sure where you're taking this. Your reference to "states" of an argument is intriguing, although I do not see how an argument can possibly be a stateful object.CSTAR 22:56, 31 Aug 2004 (UTC)

Stanford Enc. article

Wilfred Hodges has an article Logic and games (http://plato.stanford.edu/entries/logic-games/) that will be interesting in the context of this article (and elsewhere). Let me quote two paragraphs:

The links between logic and games go back a long way. If one thinks of a debate as a kind of game, then Aristotle already made the connection; his writings about syllogism are closely intertwined with his study of the aims and rules of debating. Aristotle's viewpoint survived into the common medieval name for logic: dialectics. Ramist logic, which drove out the old School logic in the mid sixteenth century, aimed to provide a set of practical tools for the orator and the debater. That view of logic had faded away by the eighteenth century. But in the mid twentieth century Charles Hamblin revived the link between dialogue and the rules of sound reasoning, soon after Paul Lorenzen had connected dialogue to constructive foundations of logic.

A different strand, not quite so old, is the use of games for teaching logic. This is probably the right way to think of the medieval game of ‘obligationes’, where a debater tries to drive his opponent into an unnecessary contradiction. We have at least two textbooks of logic from the early sixteenth century that present it as a game for an individual student, and Lewis Carroll's The Game of Logic (1887) is a more recent example in the same genre.

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Though some parts of argumentative dialogue theory can be formulated in terms of games, this would be unfortunate for several reasons:

• Note the hypothetical -- if one thinks of debate as a game

• The goal of logical argument is only in a restricted sense a win-lose game. True if the goal is to prove X to the satisfaction of the interlocutor, then one either fails or succeeds. However in most

practical cases of argument, it isn't easy to test whether this terminal state is achieved.

The game theoretic view is too explicitly stateful and largely ignores argument history (I know, histories can always be represented in state by taking state large enough) "Histories" of dialectical positions taken by individual participants are an essential ingredient of argumentative dialogue. In other words, I am thinking of a argumentative dialogue as being represented by the run of a communication protocol (for some idea of the events principals might engage in in this protocol, see van Eemeren Grootendorst). This approach has other advantages viz-- some of the "timing" issues involved in argument (for instance, delay in response in many instances may be regarded as failing to adequately respond)CSTAR 00:33, 1 Sep 2004 (UTC)

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To echo myself, I'm not saying that game semantics are the right way to frame this article, but rather there is a common idea behind them; also there are interesting points of contact between the two. Some points:

• Note the hypothetical -- if one thinks of debate as a game -- games as they are applied in the semantics of logic are generally intended to capture formally the concept of dialog. The term dialog games is widely used for just this reason.
• The goal of logical argument is only in a restricted sense a win-lose game. And dialog games are often formalised without a notion of winning; if they are they may be labelled win-lose-draw (naturally corresponding to non-bivalent approaches to logic).
• The game theoretic view is too explicitly stateful and largely ignores argument history (I know, histories can always be represented in state by taking state large enough) -- its sort of irrelevant, but recently history-free approaches to game semantics have fallen into disfavour, because of technical difficulties they have handling disjunction.
• I don't see why your idea of dialogues being modelled by a communication protocol should be considered alien to the game semantical tradition.

In the medium term (ie. after a couple of weeks or so), I'm planning on overhauling what I wrote in semantics of logic, and treating proof theoretic and game semantical approaches more thoroughly. I'll draw on Wilfred Hodges article, and I'd like there to be some commonality of ground between this article and what I write elsewhere. This is the reason I posted the above excerpt in the first place ---- Charles Stewart 01:48, 1 Sep 2004 (UTC)

I'm taking a logic class and I'm an English teacher so I'm trying to flesh out articles regarding logic and logical writing. Any help appreciated!--DennisDaniels 03:58, 2 Sep 2004 (UTC)

Empty section headings

If nobody puts anything in them I will delete them. I'm not sure any of these distinctions are useful anyway. I also strongly object to state of an argument. CSTAR 13:19, 2 Sep 2004 (UTC)

I think "state" of an argument is an idea that is natural to many perspectives when trying to model discourses (should cf. Discourse in linguitics); since one can reasonably say these are artificial and pernicnious ideas imposed on one's understanding by theoretical models, all this is POV. I agree with deleting empty headings if the body's arrival isn't imminent ---- Charles Stewart 19:48, 2 Sep 2004 (UTC)

Other meanings of Argumentation

There is another strand of 'Argumentation' that is more concerned with it's use as a machine-executable technique for qualitative decision making, and draws on work done by people sung as Dung, Fox, Parsons and McBurney (to name but a few) This is actually fairly different from this page, so I thought it might warrant something different, and should probably go under something more computer-y.

Any thoughts?

Look at the Argument page, these senses fall under possible disambiguations given there, I think. ---- Charles Stewart 10:24, 3 Sep 2004 (UTC)

Postscript -- in fact they don't, I was mixed up, but what you say might better be a page linked to from the disamb page. ---- Charles Stewart 10:28, 3 Sep 2004 (UTC)

New introductory sentence

Does this new introductory sentence add anything? The important concept I thought was preservation of validity. I think it should be removed. CSTAR 22:40, 27 Oct 2004 (UTC)

For a logical argument to be true, it must be well-formed, valid, and sound.

RV 20040302's edit

User:20040302 put as a new first paragraph:

For a logical argument to be true, it must be well-formed, valid, and sound.

Technically, an argument is not true, but statements may be. However, it does begin to summarise the requirements for deriving truth from arguments.

In my view, this is an unacceptable lead paragrph, as it assumes that logical argument must be conducted in a determinate formal language, so I've RV'ed it. ---- Charles Stewart 09:06, 28 Oct 2004 (UTC)

I added it, because from what I understand regarding argument, the three basic requirements are necessary (regardless of whether or not the argument is formal). I admit that the WFF article link appears to be particularly focused on formal logic, but remind interested parties that a syntactically/semantically incorrect set of statements hold no argumentative power. Moreover, the validity and soundness of an argument are often confused.

In essence, though I seek not to get involved in any edit war regarding this, I wished to introduce logical argument with a sentence that draws together four important concepts for understanding argumentation: truth, well-formedness, validity, and soundness. I consider the statement balanced, fair, relevant, informative and NPOV. I understand that there are differing views. (20040302)

• Different logicians use different terminology anyway. You'll find some books use 'sound' to describe arguments that other books call 'valid' and so on.

Soundness and validity

Disagreement between Charles Stewart and 20040302

On the basis of Charles Stewart remark, it may be less controversial (but also less informative, IMPOV) to keep the statement, but amended to:

For a logical argument to be true, it must be valid and sound.

The previous comment by CSTAR, I feel, undermines the importance of soundness in an argument. (20040302 09:18, 28 Oct 2004 (UTC))

The current lead paragraph is not ideal; it should be shorter, and I think it should be more informative about what constitutes an argument in formal logic. Informally, an argument cannot be valid unless it is also sound. The current Wikipedia entry for sound holds that an argument cannot be sound unless it is also valid, where validity holds iff the conclusion follows from the premises. In my view, this has the relationship between the two concepts back to front, and the formulation of validity is too strong (many intuitively valid arguments will be counted invalid according to this definition, eg. weakening/thinning). In short,the pages are, like the majority of logic pages, a mess and need sorting out. This page is not bad by the standards of the logic pages... ---- Charles Stewart 10:32, 28 Oct 2004 (UTC)

Not particularly disagreeing with Charles, though I consider finding mess elsewhere does not defend mess here. AFAIK, soundness is concerned with the truth of premisses, whereas validity is concerned with the agreement of the logical structure. For instance, MP and MT are both generally considered to be valid argument forms. But just because a an argument is valid does not make it sound.

If an argument is MT and both its premisses are true, then it is sound.

One or both premises are false.

Therefore, the argument is unsound.

From talk pages on various logic articles, it appears to be clear that the distinctions between soundness and validity are not generally understood. Also, I would agree with the wikipedia entry for soundness; sound arguments are a subset of valid arguments, which themselves are subsets of well-formed arguments. There is an excellent article concerning such issues at http://philosophy.lander.edu/logic/tvs.html (20040302)

OK, you provide a good link that provides partial justification for the way that soundness puts things (ie. a sound argument is a valid argument from true premisses). However, I do not think that this is a generally accepted definition, and the link is non-authoratative. An authoritative source, the Stanford Encyclopaedia of Philosophy disagrees with the definitions provided both for soundness and validity Their article on classical logic[1] (http://plato.stanford.edu/entries/logic-classical/) defines validity to be conservation of truth, and soundness to be a property not of logical argument per so, but of systems purported to capture (some) logical reasoning, that they only express valid arguments. I propose we adopt these definitions. ---- Charles Stewart 13:00, 28 Oct 2004 (UTC)

Postscript: I have put soundness and validity into disputed status, with links here from their talk pages. ---- Charles Stewart 13:06, 28 Oct 2004 (UTC)

I consider the link that you gave to be saying precisely the same as the one at lander.edu. I quote: This pleasant feature, called soundness, entails that no deduction takes one from true premises to a false conclusion. Also see many articles, such as http://www.ukans.edu/~acudd/phil140-s2/ , http://www.iep.utm.edu/v/val-snd.htm , etc. I quote: In short, a deductive argument must be evaluated in two ways. First, one must ask if the premises provide support for the conclusion by examining the form of the argument. If they do, then the argument is valid. Then, one must ask whether the premises are true or false in actuality. Only if an argument passes both these tests is it sound. However, if an argument does not pass these tests, its conclusion may still be true, despite that no support for its truth is given by the argument.

The latter test - (if the premises are true in actuality) is what is sometimes known as semantic validity. However, the common use for the term 'validity' in the context of logical argument, is refering to structural validity, or validity of argumentative form, or deductively valid argument.

Try a google with "soundness validity", and read the first few articles.

It appears, in light of evidence available across the internet, that your understanding actually differs from generally accepted definitions within the philosophical community.

BTW, I don't think going around sticking 'disputed' everywhere is a particularly constructive solution to anything, but that is my opinion. (20040302 14:40, 28 Oct 2004 (UTC))

I consider the link that you gave to be saying precisely the same as the one at lander.edu.

It clearly is not; it does not directly contradict the lander.edu, but it maintains the definition of soundness that I am familiar with, namely that it is a property of systems of inference intended to capture logical argument, and not logical argument per se. The Stanford Encyc. article nowhere upholds the alternative view provided on the links you give. It is quite possible that the Wikipedia article (originally penned by Larry Sanger) is the source for all of the links you provide.

I am astounded that you find it easier to believe that every article concerning validity and soundness on the Internet has referred to Wikipedia, rather than the fact that you may be mistaken. Regardless of origin, it appears that such terms are indeed common usage, and therefore validity and soundness are justified as being defined by all these sites. I certainly agree that if you can find substantive proof (greater than a single link, which IMHO does not concur with you) that there is an common alternative to the issues of soundness and validity, then I agree it is important to note both approaches in the article, on the grounds of NPOV. (20040302 21:04, 28 Oct 2004 (UTC))

I don't think going around sticking 'disputed' everywhere is a particularly constructive solution to anything

I had a simlar criticism made the last time I slapped a a 'disputed' notice on an article. It looks to me a straightforward conflict between the interests of editors in having a quiet life, and the interest of users not having questionable 'facts' passed of on them by would-be authorities. If my edits cause friction, it is possible to request mediation. ---- Charles Stewart 18:53, 28 Oct 2004 (UTC)

As a postscript, have a look at http://philosophy.hku.hk/think/arg/valid1.php

It is very clear on the distinction between validity and soundness. (20040302 14:54, 28 Oct 2004 (UTC))

The clarity of this distinction has never been doubted. It is its tension with the other definition of soundness that originates in model theory that is the problem. ---- Charles Stewart 09:17, 29 Oct 2004 (UTC)

Resolving the (informal) dispute

I have contacted Kevin Klement, who is the Logic Editor of the Internet Encyclopaedia of Philosophy, and who is therefore responsible for one of the pages User:20040302 cited above. I plan on contacting several of the authors of other entries to try and get a picture of the usage of this definition, and perhaps to find a locus solum for it.

This issue is important, since soundness is a fundamental technical term of logic, and the definition we reach here has repercussions for many pages on logic in Wikipedia. It is possible, since the two definitions are not in outright contradiction, to let both definitions be used freely in the logic pages. It would, however, in view of the pronounced tension between the two definitions, be a recipe for confusion for many users of Wikipedia, so I think we should establish a policy. Perhaps it is time to dust of my proposal for a Wikiproject Logic?

Comments sought. ---- Charles Stewart 09:17, 29 Oct 2004 (UTC)

I think that it is possibly a good solution, Charles - as long as one is careful regarding any issues of partisanship though I doubt that we need to worry about that here as we are all, in good faith, attempting to clarify rather than promote a socio-political agenda of any sort. (20040302)

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I wasn't aware there was a formal dispute, although I agree that an outside opinion would be useful. And why the reference by 20040302to someone's socio-political agenda? Am I missing something? I thought we agreed that the broader concept of logical argument should be flexible enough to accomodate argumentative dialogue and arguments in the natural and social sciences which use specialized models. Those arguments include social-political ones.

No - I was making a point about the article, not about the subject. Some articles appear to be pushing a particular agenda, rather than remaining NPOV - I was merely commenting that I think it unlikely that any of us are driven by some sort of idealism regarding the article - we all are merely seeking to improve the article according to understanding. (20040302)

As I've tried to argue previously in this Talk page (and I thought Charles Stewart generally agrees with me on that one), argumentative dialogue is more like a communication protocol between principals than a sequence of WFF's in a formal deductive system. How is such an argument -- (i.e. run of a protocol) true? Look at the Chaim Perelman --- Lucie Tyteca-Olbrechts references, cited in the article, where they do consider "truth" as a criterion for judging numerous kinds of arguments and find it inadequate to evaluate most arguments in practice. Concepts such as fairness are completely ignored by strictly semantic theories of truth. This is not to say that some communicating process semantics for such arguments wouldn't be desirable, but as far as I know this idea has only been explored very tentatively.

For example, legal arguments, though not strictly formal logical arguments are arguments nonetheless, with a structure that needs to be accounted for in some way. But how is a legal argument true? Legal arguments are evaluated by other elements in them. Should we suddenly declare, "well these aren't arguments in any recognizable sense" ?CSTAR 14:29, 29 Oct 2004 (UTC) (revised my own earlier comments which were written with numerous mistakes) CSTAR 17:19, 29 Oct 2004 (UTC)

New lead paragraphs? New version of article?

I would be happy if tthe entire article were rewritten. Nevertheless, there are several important issues which should be addressed by any version of this article.

• Logical argument as a term denoting (by abuse of language) general arguments of any kind -- Specifically, when a discussion centers around the logic of an argument, one usually refers (I think) to its structure as opposed to the kind of formal semantics it relies on.

• Argumentative dialogue

• Arguments which rely on reduction to mathematical models (e.g. Arguments about Keynesian economics, supply side economics etc could be resolved better this way)

15:48, 28 Oct 2004 (UTC)

I agree. I do not wish to see a complete restriction to the academic or philosophical definitions of a logical argument, yet at the same time, the I consider the distinctions as mentioned relavant to arguments in general. I also think that it is important to discuss the fact that much socio-political argument tends towards validity, but often are unsound by using premises that look good on the face of it, but are hollow or faulty in light of the minimum of analysis. (20040302)

CSTAR: I think there are a lot of articles about logic more deserving of a rewrite than this one. I do think the lead paragraph needs to be reworked, though. One thing the article would benefit from is a proper reconciliation between the notion of validity for informal arguments and the criteria of correctness for formal systems of inference. There is a case for merging the articles on soundness and validty with this one. ---- Charles Stewart 18:58, 28 Oct 2004 (UTC) (typo corrected Charles Stewart 07:49, 29 Oct 2004 (UTC))

Validity

There is another confusing element in this discussion which I'm afraid I'm responsible for: I'm using validity as a property of assertions and preservation of validity as a property of arguments. Now I've deliberatley (and possibly indiosyncratically) avoided applying truth to assertions and preservation of truth (ordinarily called deductive validity) to arguments. In part, I have been motivated by thinking of moral arguments or political arguments. For example, moral arguments relate sets of moral hypotheses to moral conclusions. Moral assertions may be true or false under particular interpretations of their constituent terms; rather than say an assertion is true under interpretation σ, I prefer to say assertion is valid under σ.CSTAR 06:09, 30 Oct 2004 (UTC)

Validity and soundness redux

Two attempted fixes to the disputed status have appeared, due to User:Nortexoid and User:Ancheta Wis. I rv'ed Nortexoids edits, and ancheta's usages I tidied up and put back a disputed notice on soundness. This is a just a temporary fix, I'll merge the two articles later today, as I promised Nortexoid last week and provided there are no well-founded objections. ---- Charles Stewart 12:14, 28 Feb 2005 (UTC)

Here is a small counterexample to the attempt to merge validity and soundness: A programmer is assigned the task of displaying the plural of a word. He creates a list of words and their plurals. The users type in a word, hit a key, voila, the plural. The programmer gets a raise. JoeUser asks for the plural of a word which is not in the list. The programmer is fired for raising expectations unreasonably. In other words, the poor programmer has created a valid program which remains unsound. Ancheta Wis 11:56, 2 Mar 2005 (UTC)

el stupido

Bien primero usted necesita tomar un wumpy regordete.

En el idioma ordinario, las personas se refieren a la lógica de una terminología del argumento o el uso que sugiere que un argumento se basa en reglas de inferencia de la lógica formal. Aunque los argumentos utilizan las inferencias que son indisputablemente puramente lógicas (tal como silogismos)

El contenido [showhide] 1 validez del Argumento

2 El paradigma matemático

3 Teorías de argumentos

4 Diálogo Discutidor

5 Otra La creencia predominante entre autores matemáticos es que los argumentos válidos en matemáticas son ésos que se pueden reconocer están como en el formalizable del principio en el abarcar la teoría formal. Sigue que la teoría de argumentos válidos en matemáticas es reducible a la teoría de inferencias válidas en teorías matemáticas formales. Una teoría de la validez de teorías matemáticas formales postula dos elementos claros: la sintaxis que da las reglas para cuando una fórmula se construye correctamente y semántico que es esencialmente una función de fórmulas a valores de verdad. Una expresión se dice ser válido si la función semántica asigna el valor verdadero a. Una regla de la inferencia es válida si y sólo si es validez-preservar. Un argumento es válido si y sólo si utiliza las reglas válidas de la inferencia. Note que en el caso de matemático semántico, la sintaxis y semántico son objetos matemáticos.

En el uso general, sin embargo, los argumentos son raramente formales o tienen aún el rigor de pruebaes matemáticas.

[redacte] las Teorías de Teorías de argumentos de argumentos son estrechamente relacionadas a teorías de la lógica informal. Idealmente, una teoría del argumento debe proporcionar algún mecanismo para explicar la validez de argumentos.

Un enfoque natural seguiría el paradigma y la tentativa matemáticos para definir la validez en términos de semántico de las afirmaciones en el argumento. Aunque tal enfoque apela en su sencillez, los obstáculos a avanzar esta manera es muy difícil para algo de otra manera que los argumentos puramente lógicos. Entre otros problemas, nosotros necesitamos interpretar las oraciones no sólo enteras, pero también componentes de oraciones, las frases por ejemplo sustantivas tales como El valor actualizado de renta de gobierno para los próximos doce años.

Una dificultad mayor de seguir este enfoque es eso determinando un dominio semántico apropiado no es una tarea fácil, levantando numerosos asuntos ontológicos espinosos. Levanta también la perspectiva desalentadoa de tener que trabajar fuera teorías semánticas aceptables es antes capaz de decir algo útil acerca de la comprensión y evaluar los argumentos. Para esta razón que el enfoque puramente semántico se reemplaza generalmente con otros enfoques que son más fácilmente aplicables al discurso práctico.

Para argumentos con respecto a temas tales como la probabilidad, la economía o la física, parte de los problemas semánticos se puede empujar convenientemente bajo la alfombra si podemos servirnos de un modelo del fenómeno bajo la discusión. En este caso, nosotros podemos establecer una interpretación semántica limitada que utiliza los términos del modelo y la validez del argumento es reducida a que del modelo abstracto. Esta clase de la reducción se utiliza en las ciencias naturales generalmente, y sería especialmente útil en discutir acerca de asuntos sociales si los partidos pueden convenir en un modelo. Desgraciadamente, esto reducción previa rara vez ocurre, con el resultado que argumentos acerca de la política social tienen raramente una resolución satisfactoria.

Otro enfoque deberá desarrollar una teoría del argumento pragmático, por lo menos en ciertos casos donde argumento e interacción social son estrechamente relacionados. Esto es muy útil cuando la meta del argumento lógico deberá establecer una resolución mutuamente satisfactoria de una diferencia de la opinión entre individuos llamas Discutidoras de poopy de diálogo están delicioso

Creo que Ud. se equivocó de idioma.--CSTAR 21:33, 5 Apr 2005 (UTC)