LogicalFallaciesIntroductionandActivitiesWhatisalogicalfallacy?Afallacyisanerrorofreasoning.TheseareflawedstatementsthatoftensoundtrueLogicalfallaciesareoftenusedtostrengthenanargument,butifthereaderdetectsthemtheargumentcanbackfire,anddamagethewriter’scredibility

Origins Theword“fallacy”mayderivefromtheLatinwordfalleremeaning,“todeceive,totrip,toleadintoerrorortotrick.”ThewordmayalsoderivefromtheGreekphelos,meaning“deceitful.”/talitha/fallacies.htmWhystudylogicalfallacies?Itisimportanttodeveloplogicalfallacydetectionskillsinyourownwriting,aswellasothers’.Thinkofthisas“intellectualkung-fu:theartofintellectualselfdefense.”(LogicalFallaciesHandlist)EitherwedrillintheANWR(北極國家野生動(dòng)物保護(hù)區(qū)）orwewillpaytwiceasmuchforgasoline.Whatfallacydoesthisrepresent?EitherwedrillintheANWRorwewillpaytwiceasmuchforgasoline.Theeither/orfallacyreducesacomplexargumenttojusttwopositions.Mighttherebeanotherwaytokeepgaspricesdown?Eitheryoubelieveme,oryoudon’t.Either/orreasoningistemptingbecauseitmakestheworldmoreunderstandable.It’seasiertochoosewhentherearejusttwochoices.Unfortunately,therearealmostalwaysseveralchoices,andtheworldismorecomplicatedthanwethink.Therefore,theresponsiblethingtodoistoacknowledgeandthinkaboutthesecomplications.Somemorepopulareither/orfallacies:Eitherwehaveacompletelyfreemarketorwearesocialists.You’reeitheraRepublicanoraDemocrat.Youeitherlovecheese,oryouhavenotaste.Whatfallacyisthis?BuildingamosqueneargroundzeroiswrongbecausemostAmericansthinkthemosqueshouldnotbebuiltthere.Thebandwagon(從眾效應(yīng))

appeal,orappealtofalseauthority,pretendsthatanargumentistruejustbecauseeveryonebelievesitis.Buthistoryrevealsmanycaseswhenthemajorityofpeoplewerewrong.BuildingamosqueneargroundzeroiswrongbecausemostAmericansthinkthemosqueshouldnotbebuiltthere.Justbecauseeveryonedoessomethingorbelievessomething,thatdoesn’tmakeittrue—notevenifallthemostpopularandintelligentpeoplebelieveit.Formoreonthis,seeIbsen’sAnEnemyofthePeople.Advertisementsgiveusmanybandwagonappeals.Whatisthefallacyinthisreasoning?

Weshouldn’tregulatethecarbondioxideemissionsofcorporations.Volcanoescontributesubstantiallymorecarbondioxideemissionstotheatmospherethanpeopledo.Theredherring(轉(zhuǎn)移注意力)triestodistractyou.

Weshouldn’tregulatethecarbondioxideemissionsofcorporations.Volcanoescontributesubstantiallymorecarbondioxideemissionstotheatmospherethanpeopledo.Mostpeoplewhoknewthefactswouldagreethatvolcanoesspewalotofcarbondioxide,perhapsevenmorethanhumansproduce.Butwhatdoesthathavetodowiththecarbondioxidepeopleproduce?Theredherringtriestodistractyou.Nothing.Ifcarbondioxidedamagestheenvironment,thenitshouldbedecreasedatallsources.Thisisaredherringbecausethearguerseekstodistractusfromthemainissue—regulatingCO2emissions—bybringingupvolcanoes.

Weshouldn’tregulatethecarbondioxideemissionsofcorporations.Volcanoescontributesubstantiallymorecarbondioxideemissionstotheatmospherethanpeopledo.Theredherringtriestodistractyou.Forthisargumenttoberelevant,thesubjectoftheargumentwouldhavetobewhetherthereisanythingwecandotostopclimatechangeatall.Solongastheargumentfocusesonregulatingcarbondioxideemissions,thisisaredherring.

Weshouldn’tregulatethecarbondioxideemissionsofcorporations.Volcanoescontributesubstantiallymorecarbondioxideemissionstotheatmospherethanpeopledo.Thisfallacyis....

Jenniferlivesinabigbuilding,soshemusthaveabigapartment.Thenonsequitur（不當(dāng)結(jié)論）:areasonthathasnorelationshiptotheclaim.

Jenniferlivesinabigbuilding,soshemusthaveabigapartment.Jennifer’sbuildingcertainlyislarge.Nobodydisputesthat.Butdoesitnecessarilyfollowthatherapartmentisalsolarge?No.Thenonsequitur:areasonthathasnorelationshiptotheclaim.WeneedrelevantevidenceaboutthesizeofJen’sapartmentbeforewecancometoaconclusion.ThisargumentaboutAustraliansisfallaciousforwhatreason?WhenIwasinAustralia,someonestolemywallet.Andafewyearsago,whenmywifewasvisiting,someonestoleherpurse!ThoseAustraliansareabunchofthievesandpurse-snatchers.Ahastygeneralization（以偏概全）makesaconclusionbasedontoolittleevidence.WhenIwasinAustralia,someonestolemywallet.Andafewyearsago,whenmywifewasvisiting,someonestoleherpurse!ThoseAustraliansareabunchofthievesandpurse-snatchers.Failingtoprovidesufficientgroundsforareasonisessentiallythesameasmakingahastygeneralization.Bush’sargumentforinvadingIraqwaswrongbecausehe’sstupid.Imean,howcouldweentrustourpowerfulmilitarytosomeonewhocouldbarelyread?

What’sthefallacyupthere?Ordownthere? Obama’spoliciescannotbetrustedbecauseheliedaboutquittingsmoking.Whatelseishelyingabout?Theadhominem（人身攻擊）fallacyattacksthepersonmakingtheargumentinsteadoftheargumentitself.MaybeBushisapoorreader.MaybeObamadidfailtoquitsmoking.Butthatdoesn’tmeantheirargumentsareworthless.Wemustjudgetheargumentsontheirownmerits.ThePatriotActviolatesourprivacybecauseittrespassesintoourpersonallives.Whatisthefallacyhere?ThePatriotActviolatesourprivacybecauseittrespassesintoourpersonallives.Circularreasoning（循環(huán)論證）simplyrestatestheclaimasareasonindifferentwords.Violatingprivacyisthesameastrespassingintopersonallives.Studentsshouldnotbeallowedtoparkinlotsnowreservedforfacultybecausethoselotsshouldbeforfacultyonly.ThePatriotActviolatesourprivacybecauseittrespassesintoourpersonallives.Ifyouareconstructinganargumentandyoumakethismistake,theresultisthatthearguerstatesawholeclaimasareason.Then,thearguerisobligatedtosupportthatwholeclaim,whichismasqueradingasareason,withgroundsinsteadofreasons.It’simpossible!Whatisthefallacyhere?WhileIwaswritingmyEnglishpaper,IdrankaRedBull.ThenIgotanA.Thoseredbullsaremagic!Posthoc,ergopropterhoc（因果顛倒）positsacause/effectrelationshipwherethereisreallyjustarelationshipofsequence.WhileIwaswritingmyEnglishpaper,IdrankaRedBull.ThenIgotanA.Thoseredbullsaremagic!WhocansaywhythispersongotthatA?JustbecausetheydranktheRedBullfirst,thatdoesn’tmeantheRedBullcausedit.Posthoc,ergopropterhocislatinfor“Afterthis,thereforebecauseofthis.”Whenconstructinganargument:Don’tbetempteddownthedarkpathoffalselogic.Whenconstructingyourlogicalappeals,takecarethattheyareallfoundedonlegitimatelogicalpremises,andthatyourevidenceisalwaysbothsufficientandrelevant.Whenreadinganargument:Watchoutforlogicalfallaciesthatthearguermayusetotrickyou.Ifyoucanidentifyalogicalfallacyinanargument,thenyouareonyourwaytodisprovingthatargumentanddiscreditingitsauthor.Famouslogicalfallacies:EventhemostsuperficialobservationshowsthatNature’srestrictedformofpropagationandincreaseisanalmostrigidbasiclawoftheinnumerableformsofexpressionofhervitalurge.Everyanimalmatesonl