The Logical FallaciesArgument&fallacies. What is logical fallacy?why should we learn logical fallacies?fallacies in and out the textcontents&Arguments, like men, are often pretenders. PlatofailtoprovideconclusiveevidenceWhat are fallacies?What are fallacies?&The logic is missing or something in the case is not clear.&is not necessarily a false statementis not necessarily a false statement. .&common and quite persuasive at least common and quite persuasive at least to the casual readerto the casual readers s or listener or listeners s The Angel in the HouseThe Angel in the House？ Girls are not good at science. Girls are not good at science. Loose Generalization/Dicto Simpliciter(过度概括）过度概括）It is an overly broad and absolute statement, which does not allow for any exceptions of complexity.The most beautiful woman scientistThe most beautiful woman scientist HedyLamarrThemotherofCDMAphonePage71,para6974Exerciseisgood.Thereforeeverybodyshouldexercise.Exercise is good isanunqualifiedgeneralization.Forinstance,ifyouhaveheartdisease,exerciseisbad,notgood.usually goodorgoodformost people.“All generalizations are false, including this “All generalizations are false, including this one.”one.”Mark TwainMark TwainAfloodhappenedafterthecometappeared;therefore,thecometcausedtheflood. Post Hoc Fallacy/False Cause（牵强附会附会/假性因果）假性因果）It is a fallacy in which one event is said It is a fallacy in which one event is said to have caused another simply because to have caused another simply because they occurred in sequence.they occurred in sequence.Page71, Para8085Page71, Para8085LetsnottakeBillonourpicnic.Everytimewetakehimoutwithus,itrains.EulaBeckerdoesntcausetherain.Shehasnoconnectionwiththerain.Guns are like hammerstheyre both tools with Guns are like hammerstheyre both tools with metal parts that could be used to kill someone. metal parts that could be used to kill someone. And yet it would be ridiculous to restrict the And yet it would be ridiculous to restrict the purchase of hammersso restrictions on purchasing purchase of hammersso restrictions on purchasing guns are equally ridiculous.guns are equally ridiculous. False /weak Analogy(错误类比）比）It presumes that if two things or people It presumes that if two things or people are alike in one or two ways, they will be are alike in one or two ways, they will be alike in other ways alike in other ways tootoo. .Page 72Page 72，Para 105108Para 105108&Studentsshouldbeallowedtolookattheirtextbooksduringexaminations.Afterall,surgeonshaveX-raystoguidethemduringanoperation,lawyershavebriefstoguidethemduringatrial,carpentershaveblueprintstoguidethemwhentheyarebuildingahouse.&Doctors,lawyers,andcarpentersarenttakingatesttoseehowmuchtheyhavelearned,butstudentsare.Thesituationsarealtogetherdifferent,andyoucantmakeananalogybetweenthem.Backfire: Backfire: &Para129hastygeneralizationpara75&Para133falseanalogypara105&Para137admisericordiampara99&Para144hypothesiscontrarytofactpara109&Para146dictosimpliciterpara71&Para152poisoningthewellpara115go further into the textgo further into the text&Bandwagoneffect(随波逐流） PeteyBurch&HastyGeneralization(草率结论）para7579&ContradictoryPremises(矛盾前提）：para8694&AdMisericordiam(文不对题）：Para99104&HypothesisContrary(与事实相反的假设）para109114&PoisoningTheWell(井里投毒）para115120Excessive drinking is detrimental Excessive drinking is detrimental to health because it causes harm to health because it causes harm to the body. to the body. Circular Reasoning（循环论证）（循环论证）It occurs when you state your position and then It occurs when you state your position and then restate it in different words as your reason.restate it in different words as your reason.Either we must set up a strict dress code, or employees will dress inappropriately. Black and White Thinking（二分法（二分法思考）思考）It is a form of reasoning that presumes that there It is a form of reasoning that presumes that there are only two possibilities, when there may be are only two possibilities, when there may be many.many. I cant allow my son to join that mountain I cant allow my son to join that mountain climbing club. If he does, he will be climbing climbing club. If he does, he will be climbing mountains at least once a week, then twice a mountains at least once a week, then twice a week. Before you know it, he will spend all of week. Before you know it, he will spend all of his time climbing mountains and wont be able his time climbing mountains and wont be able to keep up with his studies.to keep up with his studies. Slippery-SlopeSlippery-Slope（滑坡效应）（滑坡效应）（滑坡效应）（滑坡效应）It presumes a chain of events that is It presumes a chain of events that is only likely to occur from one original only likely to occur from one original event.event.summarysummary&Loosegeneralization/Dictosimpliciter(过度概括）&Posthocfallacy/Falsecause(牵强附会）&Weak/Falseanalogy(错误类比）&Bandwagoneffect（随波逐流） &HastyGeneralization(草率结论）&ContradictoryPremises(矛盾前提）&AdMisericordiam(文不对题）&HypothesisContrary(与事实相反的假设）&PoisoningTheWell(井里投毒）&Blackandwhitethinking（二分法思考）&Circularreasoning(循环论证）&slippery-slope(滑坡效应）why learn logical fallacieswhy learn logical fallacies1.smart(IQ&EQ）impressthejudgeandaudience.2.removinganargumentfromthetableratherthanjustweakeningit.3.prepareforyouopponentsargumentratherthanbeingtakenoffguard.羡慕嫉妒有木有浪漫纯美有米有LOVE IS A FALLACY&Whatconstitutestheargument,andwhattherelationbetweenargumentandfallacy?Argumentconsistsoftwoparts:aconclusionandcertainpremises.Anargumentthatfailstobeconclusivelydeducedisinvalid,whichissaidtobefallacious.why learn logical fallacieswhy learn logical fallacies1.smart(IQ&EQ）impressthejudgeandaudience.2.removinganargumentfromthetableratherthanjustweakeningit.3.prepareforyouopponentsargumentratherthanbeingtakenoffguard.time to showtime to show&1.DefenseAttorney:Thisyoungmancouldnotpossiblyhavekilledhisparents,becauseheisnowanorphan.()A. PoisoningTheWellB.CircularReasoningC. BandwagonD.Noneoftheabove&2.Mindandrivers,canbebothbroad.Itisaknownfactthatthebroadertheriver,theshalloweritis.Thereforeitmustbetrue,thatthebroaderthemindis,theshalloweritis.()A.FalseanalogyB.FalsecauseC.BlackeandwhitethinkingD.Noneoftheabove&Iwouldnthavecheatedonmyincometaxes,buteveryoneelsedoes,sowhyshouldtI?()A.slipper-slopeB.bandwagoneffectC.loosegenerationD.Noneoftheabove