Informal logic

Informal logic, intuitively, refers to the principles oflogic and logical thought outside of a formal setting.However, perhaps because of the “informal” in the ti-tle, the precise definition of “informal logic” is a mat-ter of some dispute.[1] Ralph H. Johnson and J. AnthonyBlair define informal logic as “a branch of logic whosetask is to develop non-formal standards, criteria, proce-dures for the analysis, interpretation, evaluation, criticismand construction of argumentation.”[2] This definition re-flects what had been implicit in their practice and whatothers[3][4][5] were doing in their informal logic texts.Informal logic is associated with (informal) fallacies,critical thinking, the Thinking Skills Movement[6] andthe interdisciplinary inquiry known as argumentation the-ory. Frans H. van Eemeren writes that the label “informallogic” covers a “collection of normative approaches to thestudy of reasoning in ordinary language that remain closerto the practice of argumentation than formal logic.”[7]

1 History

Informal logic as a distinguished enterprise under thisname emerged roughly in the late 1970s as a sub-fieldof philosophy. The naming of the field was preceded bythe appearance of a number of textbooks that rejectedthe symbolic approach to logic on pedagogical groundsas inappropriate and unhelpful for introductory textbookson logic for a general audience, for example Howard Ka-hane's Logic and Contemporary Rhetoric, subtitled “TheUse of Reason in Everyday Life”, first published in 1971.Kahane’s textbook was described on the notice of hisdeath in the Proceedings And Addresses of the AmericanPhilosophical Association (2002) as “a text in informallogic, [that] was intended to enable students to cope withthe misleading rhetoric one frequently finds in the me-dia and in political discourse. It was organized around adiscussion of fallacies, and was meant to be a practical in-strument for dealing with the problems of everyday life.[It has] ... gone through many editions; [it is] ... still inprint; and the thousands upon thousands of students whohave taken courses in which his text [was] ... used canthank Howard for contributing to their ability to dissectarguments and avoid the deceptions of deceitful rhetoric.He tried to put into practice the ideal of discourse thataims at truth rather than merely at persuasion. (Hausmanet al. 2002)"[8][9] Other textbooks from the era taking thisapproach were Michael Scriven's Reasoning (Edgepress,1976) and Logical Self-Defense by Ralph Johnson and J.

Anthony Blair, first published in 1977.[8] Earlier precur-sors in this tradition can be considered Monroe Beards-ley's Practical Logic (1950) and Stephen Toulmin's TheUses of Argument (1958).[10]

The field perhaps became recognized under its currentname with the First International Symposium on Infor-mal Logic held in 1978. Although initially motivated bya new pedagogical approach to undergraduate logic text-books, the scope of the field was basically defined by alist of 13 problems and issues which Blair and Johnsonincluded as an appendix to their keynote address at thissymposium:[8][11]

• the theory of logical criticism

• the theory of argument

• the theory of fallacy

• the fallacy approach vs. the critical thinking ap-proach

• the viability of the inductive/deductive dichotomy

• the ethics of argumentation and logical criticism

• the problem of assumptions and missing premises

• the problem of context

• methods of extracting arguments from context

• methods of displaying arguments

• the problem of pedagogy

• the nature, division and scope of informal logic

• the relationship of informal logic to other inquiries

David Hitchcock argues that the naming of the field wasunfortunate, and that philosophy of argument would havebeen more appropriate. He argues that more undergrad-uate students in North America study informal logic thanany other branch of philosophy, but that as of 2003 infor-mal logic (or philosophy of argument) was not recognizedas separate sub-field by the World Congress of Philoso-phy.[8] Frans H. van Eemeren wrote that “informal logic”is mainly an approach to argumentation advanced by agroup of US and Canadian philosophers and largely basedon the previous works of Stephen Toulmin and to a lesserextent those of Chaïm Perelman.[7]

Alongside the symposia, since 1983 the journal Infor-mal Logic has been the publication of record of the field,

1

2 4 RELATION TO CRITICAL THINKING

with Blair and Johnson as initial editors, with the edito-rial board now including two other colleagues from theUniversity of Windsor—Christopher Tindale and HansV. Hansen.[12] Other journals that regularly publish arti-cles on informal logic include Argumentation (founded in1986), Philosophy and Rhetoric, Argumentation and Ad-vocacy (the journal of the American Forensic Associa-tion), and Inquiry: Critical Thinking Across the Disciplines(founded in 1988).[13]

2 Proposed definitions

Johnson and Blair (2000) proposed the following defi-nition: “Informal logic designates that branch of logicwhose task is to develop non-formal2 standards, crite-ria, procedures for the analysis, interpretation, evaluation,critique and construction of argumentation in everydaydiscourse.” Their meaning of non-formal2 is taken fromBarth and Krabbe (1982), which is explained below.To understand the definition above, one must understand“informal” which takes its meaning in contrast to its coun-terpart “formal.” (This point was not made for a verylong time, hence the nature of informal logic remainedopaque, even to those involved in it, for a period of time.)Here it is helpful to have recourse[14] to Barth and Krabbe(1982:14f) where they distinguish three senses of theterm “form.” By “form1,” Barth and Krabbe mean thesense of the term which derives from the Platonic idea ofform—the ultimate metaphysical unit. Barth and Krabbeclaim that most traditional logic is formal in this sense.That is, syllogistic logic is a logic of termswhere the termscould naturally be understood as place-holders for Pla-tonic (or Aristotelian) forms. In this first sense of “form,”almost all logic is informal (not-formal). Understandinginformal logic this way would be much too broad to beuseful.By “form2,” Barth and Krabbe mean the form of sen-tences and statements as these are understood in mod-ern systems of logic. Here validity is the focus: if thepremises are true, the conclusion must then also be true.Now validity has to do with the logical form of the state-ment that makes up the argument. In this sense of “for-mal,” most modern and contemporary logic is “formal.”That is, such logics canonize the notion of logical form,and the notion of validity plays the central normativerole. In this second sense of form, informal logic is not-formal, because it abandons the notion of logical form asthe key to understanding the structure of arguments, andlikewise retires validity as normative for the purposes ofthe evaluation of argument. It seems to many that va-lidity is too stringent a requirement, that there are goodarguments in which the conclusion is supported by thepremises even though it does not follow necessarily fromthem (as validity requires). An argument in which theconclusion is thought to be “beyond reasonable doubt,given the premises” is sufficient in law to cause a person

to be sentenced to death, even though it does not meet thestandard of logical validity. This type of argument, basedon accumulation of evidence rather than pure deduction,is called a conductive argument.By “form3,” Barth and Krabbe mean to refer to “proce-dures which are somehow regulated or regimented, whichtake place according to some set of rules.” Barth andKrabbe say that “we do not defend formality3 of all kindsand under all circumstances.” Rather “we defend the the-sis that verbal dialectics must have a certain form (i.e.,must proceed according to certain rules) in order that onecan speak of the discussion as being won or lost” (19). Inthis third sense of “form”, informal logic can be formal,for there is nothing in the informal logic enterprise thatstands opposed to the idea that argumentative discourseshould be subject to norms, i.e., subject to rules, crite-ria, standards or procedures. Informal logic does presentstandards for the evaluation of argument, procedures fordetecting missing premises etc.Johnson and Blair (2000) noticed a limitation of theirown definition, particularly with respect to “everyday dis-course”, which could indicate that it does not seek to un-derstand specialized, domain-specific arguments made innatural languages. Consequently, they have argued thatthe crucial divide is between arguments made in formallanguages and those made in natural languages.Fisher and Scriven (1997) proposed a more encompass-ing definition, seeing informal logic as “the disciplinewhich studies the practice of critical thinking and pro-vides its intellectual spine”. By “critical thinking” theyunderstand “skilled and active interpretation and evalu-ation of observations and communications, informationand argumentation.”[15]

3 Criticisms

Some hold the view that informal logic is not a branch orsubdiscipline of logic, or even the view that there cannotbe such a thing as informal logic.[16][17][18] Massey criti-cizes informal logic on the grounds that it has no theoryunderpinning it. Informal logic, he says, requires detailedclassification schemes to organize it, which in other disci-plines is provided by the underlying theory. He maintainsthat there is no method of establishing the invalidity ofan argument aside from the formal method, and that thestudy of fallacies may be of more interest to other disci-plines, like psychology, than to philosophy and logic.[16]

4 Relation to critical thinking

See also: Critical thinking

Since the 1980s, informal logic has been partnered andeven equated,[19] in the minds of many, with critical

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thinking. The precise definition of "critical thinking" is asubject of much dispute.[20] Critical thinking, as definedby Johnson, is the evaluation of an intellectual product(an argument, an explanation, a theory) in terms of itsstrengths and weaknesses.[20] While critical thinking willinclude evaluation of arguments and hence require skillsof argumentation including informal logic, critical think-ing requires additional abilities not supplied by informallogic, such as the ability to obtain and assess informationand to clarify meaning. Also, many believe that criticalthinking requires certain dispositions.[21] Understood inthis way, “critical thinking” is a broad term for the atti-tudes and skills that are involved in analyzing and evaluat-ing arguments. The critical thinking movement promotescritical thinking as an educational ideal. The movementemerged with great force in the '80s in North Americaas part of an ongoing critique of education as regards thethinking skills not being taught.

5 Relation to argumentation the-ory

See also: Argumentation theory

The social, communicative practice of argumentationcan and should be distinguished from implication (orentailment)—a relationship between propositions; andfrom inference—a mental activity typically thought ofas the drawing of a conclusion from premises. Informallogic may thus be said to be a logic of argumentation, asdistinguished from implication and inference.[22]

Argumentation theory (or the theory of argumentation)has come to be the term that designates the theoreticalstudy of argumentation. This study is interdisciplinary inthe sense that no one discipline will be able to providea complete account. A full appreciation of argumenta-tion requires insights from logic (both formal and infor-mal), rhetoric, communication theory, linguistics, psy-chology, and, increasingly, computer science. Since the1970s, there has been significant agreement that thereare three basic approaches to argumentation theory: thelogical, the rhetorical and the dialectical. According toWenzel,[23] the logical approach deals with the product,the dialectical with the process, and the rhetorical withthe procedure. Thus, informal logic is one contributorto this inquiry, being most especially concerned with thenorms of argument.

6 See also• Argument map

• Informal fallacy

• Inference objection

• Lemma

• Philosophy of language

• Semantics

7 Footnotes[1] See Johnson 1999 for a survey of definitions.

[2] Johnson, Ralph H., and Blair, J. Anthony (1987), “TheCurrent State of Informal Logic”, Informal Logic, 9(2–3), 147–151. Johnson & Blair added "... in everydaydiscourse” but in (2000), modified their definition, andbroadened the focus now to include the sorts of argumentthat occurs not just in everyday discourse but also disci-plined inquiry—whatWeinstein (1990) calls “stylized dis-course.”

[3] Scriven, 1976

[4] Munson, 1976

[5] Fogelin, 1978

[6] Resnick, 1989

[7] Frans H. van Eemeren (2009). “The Study of Argumen-tation”. In Andrea A. Lunsford, Kirt H. Wilson, Rosa A.Eberly. The SAGE handbook of rhetorical studies. SAGE.p. 117. ISBN 978-1-4129-0950-1.

[8] David Hitchcock, Informal logic 25 years later in InformalLogic at 25: Proceedings of theWindsor Conference (OSSA2003)

[9] JSTOR 3218569

[10] Fisher (2004) p. vii

[11] J. Anthony Blair and Ralph H. Johnson (eds.), InformalLogic: The First International Symposium, 3-28. Pt.Reyes, CA: Edgepress

[12] http://ojs.uwindsor.ca/ojs/leddy/index.php/informal_logic/about/editorialTeam

[13] Johnson and Blair (2000), p. 100

[14] As Johnson (1999) does.

[15] Johnson and Blair (2000), p. 95

[16] Massey, 1981

[17] Woods, 1980

[18] Woods, 2000

[19] Johnson (2000) takes the conflation to be part of the Net-work Problem and holds that settling the issue will requirea theory of reasoning.

[20] Johnson, 1992

[21] Ennis, 1987

[22] Johnson, 1999

[23] Wenzel (1990)

4 8 REFERENCES

8 References

• Barth, E. M., & Krabbe, E. C. W. (Eds.). (1982).From axiom to dialogue: A philosophical studyof logics and argumentation. Berlin: Walter DeGruyter.

• Blair, J. A & Johnson, R.H. (1980). The recent de-velopment of informal logic. In J. Anthony Blairand Ralph H. Johnson (Eds.). Informal logic: Thefirst international symposium, (pp. 3–28). Inver-ness, CA: Edgepress.

• Ennis, R.H. (1987). A taxonomy of critical think-ing dispositions and abilities. In J.B. Baron and R.J.Sternberg (Eds.), Teaching critical thinking skills:Theory and practice, (pp. 9–26). New York: Free-man.

• Eemeren, F. H. van, &Grootendorst, R. (1992). Ar-gumentation, communication and fallacies. Hills-dale, NJ: Lawrence Erlbaum Associates.

• Fisher, A. and Scriven, M. (1997). Critical think-ing: Its definition and assessment. Point Reyes, CA:Edgepress

• Fisher, Alec (2004). The logic of real arguments(2nd ed.). Cambridge University Press. ISBN 978-0-521-65481-4.

• Govier, T. (1987). Problems in argument analysisand evaluation. Dordrecht: Foris.

• Govier, T. (1999). The Philosophy of Argument.Newport News, VA: Vale Press.

• Groarke, L. (2006). Informal Logic. Stanford Ency-clopedia of Philosophy, from http://plato.stanford.edu/entries/logic-informal/

• Hitchcock, David (2007). “Informal logic and theconcept of argument”. In Jacquette, Dale. Philos-ophy of logic. Elsevier. ISBN 978-0-444-51541-4.preprint

• Johnson, R. H. (1992). The problem of definingcritical thinking. In S. P. Norris (Ed.), The gen-eralizability of critical thinking (pp. 38–53). NewYork: Teachers College Press. (Reprinted in John-son (1996).)

• Johnson, R. H. (1996). The rise of informal logic.Newport News, VA: Vale Press

• Johnson, R. H. (1999). The relation between formaland informal logic. Argumentation, 13(3) 265-74.

• Johnson, R. H. (2000). Manifest rationality: Apragmatic theory of argument. Mahwah, NJ:Lawrence Erlbaum Associates.

• Johnson, R. H. & Blair, J. A. (1987). The currentstate of informal logic. Informal Logic 9, 147-51.

• Johnson, R. H. & Blair, J. A. (1996). Informallogic and critical thinking. In F. van Eemeren, R.Grootendorst, & F. Snoeck Henkemans (Eds.), Fun-damentals of argumentation theory (pp. 383–86).Mahwah, NJ: Lawrence Erlbaum Associates

• Johnson, R. H. & Blair, J. A. (2002). Informallogic and the reconfiguration of logic. In D. Gabbay,R. H. Johnson, H.-J. Ohlbach and J. Woods (Eds.).Handbook of the logic of argument and inference:The turn towards the practical (pp. 339–396). El-sivier: North Holland.

• MacFarlane, J. (2005). Logical Constants. StanfordEncyclopedia of Philosophy.

• Massey, G. (1981). The fallacy behind fallacies.Midwest Studies of Philosophy, 6, 489-500.

• Munson, R. (1976). The way of words: an informallogic. Boston: Houghton Mifflin.

• Resnick, L. (1987). Education and learning to think.Washington, DC: National Academy Press..

• Walton, D. N. (1990). What is reasoning? What isan argument? The Journal of Philosophy, 87, 399-419.

• Weinstein, M. (1990) Towards a research agenda forinformal logic and critical thinking. Informal Logic,12, 121-143.

• Wenzel, J. 1990 Three perspectives on argumen-tation. In R Trapp and J Scheutz, (Eds.), Per-spectives on argumentation: Essays in honour ofWayne Brockreide, 9-26 Waveland Press: ProspectHeights, IL

• Woods, J. (1980). What is informal logic? In J.A.Blair & R. H. Johnson (Eds.), Informal Logic: TheFirst International Symposium (pp. 57–68). PointReyes, CA: Edgepress.

8.1 Special journal issue

The open access issue 20(2) of Informal Logic from year2000 groups a number of papers addressing foundationalissues, based on the Panel on Informal Logic that was heldat the 1998 World Congress of Philosophy, including:

• Hitchcock, D. (2000) The significance of informallogic for philosophy. Informal Logic 20(2), 129-138.

• Johnson, R. H. &Blair, J. A. (2000). Informal logic:An overview. Informal Logic 20(2): 93-99.

• Woods, J. (2000). How Philosophical is InformalLogic? Informal Logic 20(2): 139-167. 2000

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8.2 Textbooks

• Kahane, H. (1971). Logic and contemporaryrhetoric:The use of reasoning in everyday life. Bel-mont: Wadsworth. Still in print as Nancy Cavender;Howard Kahane (2009). Logic and ContemporaryRhetoric: The Use of Reason in Everyday Life (11thed.). Cengage Learning. ISBN 978-0-495-80411-6.

• Scriven, M. (1976). Reasoning. New York. Mc-Graw Hill.

• Johnson, R. H. & Blair, J. A. (1977). Logical self-defense. Toronto: McGraw-Hill Ryerson. US Edi-tion. (2006). New York: Idebate Press.

• Fogelin, R.J. (1978). Understanding arguments: Anintroduction to informal logic. New York: Har-court, Brace, Jovanovich. Still in print as Sinnott-Armstrong, Walter; Fogelin, Robert (2010), Un-derstanding Arguments: An Introduction to InformalLogic (8th ed.), Belmont, California: WadsworthCengage Learning, ISBN 978-0-495-60395-5

• Stephen N. Thomas (1997). Practical reasoning innatural language (4th ed.). Prentice Hall. ISBN978-0-13-678269-8.

• Irving M. Copi; Keith Burgess-Jackson (1996). In-formal logic (3rd ed.). Prentice Hall. ISBN 978-0-13-229048-7.

• Woods, John, Andrew Irvine and Douglas Walton,2004. Argument: Critical Thinking, Logic and theFallacies. Toronto: Prentice Hall

• Groarke, Leo and Christopher Tindale, 2004. GoodReasoning Matters! (3rd edition). Toronto: OxfordUniversity Press

• Douglas N. Walton (2008). Informal logic: a prag-matic approach (2nd ed.). Cambridge UniversityPress. ISBN 978-0-521-71380-1.

• Trudy Govier (2009). A Practical Study of Argu-ment (7th ed.). Cengage Learning. ISBN 978-0-495-60340-5.

9 External links• Informal Logic entry by Leo Groarke in the StanfordEncyclopedia of Philosophy

6 10 TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES

10 Text and image sources, contributors, and licenses

10.1 Text• Informal logic Source: http://en.wikipedia.org/wiki/Informal%20logic?oldid=640996111 Contributors: Chris Q, DennisDaniels, Kwertii,Pcb21, Docu, Julesd, Dysprosia, Markhurd, Furrykef, Hyacinth, Tomchiukc, Leonard G., CSTAR, Paulscrawl, Guppyfinsoup, Chalst,Femto, A.t.bruland, Velho, Simetrical, Mindmatrix, Rjwilmsi, Gurch, Mattpeck, Tsch81, NawlinWiki, NostinAdrek, Closedmouth,GraemeL, SmackBot, Stev0, Bluebot, Colonies Chris, Jon Awbrey, Byelf2007, Grumpyyoungman01, Meco, JohnsonRalph, Moreschi,Gregbard, Kpossin, Steel, Al Lemos, Escarbot, Doremítzwr, WinBot, Deeplogic, Clan-destine, Cathalwoods, Gomm, Gwern, R'n'B,RickardV, Adedayoojo, Homo logos, Nburden, Igglebop, Guillaume2303, Ontoraul, GlassFET, Kumioko (renamed), ClueBot, Napzilla,Staticshakedown, Addbot, SpBot, Lightbot, Luckas-bot, Luce nordica, AnomieBOT, LilHelpa, Omnipaedista, Gerald Roark, FrescoBot,LucienBOT, Machine Elf 1735, Abductive, Wotnow, John of Reading, ZéroBot, Tijfo098, ClueBot NG, Helpful Pixie Bot, GabeIglesiaand Anonymous: 38

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