Deductive-reasoning-vs-Inductive-reasoning-2011-8-25-归纳和演绎.ppt

LegalReasoning DeductiveReasoningV InductiveReasoning Everylegalanalysisshouldbeginatthepointofreason continuealongapathoflogicandarriveatafundamentallyfairresult DouglasLind Awell knowncartoonaboutjudicialreasoningisillustrative Ninedistinguishedjudgesinrobessitinarowbehindahighrostrum Solemnexpressionsgracetheirfaces andonejudgeisreadingfromapieceofpaper Mydissentingopinionwillbebrief hesays You reallfullofcrap Case1 A Allmenaremortal B Socratesisaman C Question Whatreasoningisusedinthiscase A BandCcanbetitledas and KeytoCase1 DeductiveReasoning Majorpremise Allmenaremortal MinorPremise Socratesisaman Conclusion Socratesismortal Attention Ifweuseinductivereasoninghere therewouldbeaninvalidapplicationifoneconcluded Therefore Socratesisallmen Case2 DeductiveReasoning MajorPremise Afoothasfivetoes MinorPremise Thedistanceisonefoot Conclusion Thedistanceisfivetoes Question What syourcommentonit KeytoCase2 Asyllogismmayproduceaninvalidconclusionwhenthemeaningofwordsischangedfromthemajorpremisetotheminorpremise Case3 LegalDeductiveReasoning Rule CarryingaConcealedPistolisaFelony Facts Arenaswascarryingaconcealedpistol LegalConclusion Arenascommittedafelony Case4 LegalDeductiveReasoning Rule Tobeenforceable acontractforthesaleofgoodsforapriceof 500ormoremustbeinwriting Facts Theoralcontractforthesaleofthesegoodswasnotfor 500ormore Legalconclusion Thecontractinthiscasewasenforceable Case5 LegalDeductiveReasoning Rule Theownerofpropertywhichhasbeenstolenfromhimisentitledtorecoverthepropertyfromabonafidepurchaserfromthethief butmaynotrecoverthepropertyfromabonafidepurchaserfromapersonwhoobtainedpropertyfromtheownerbyfraudulentinducementFacts DefendantHalewasabonafidepurchaserfromAbbott whoobtainedthepropertyfromtheowner Costello bymeansoffraudulentinducementLegalConclusion Costello theowner cannotrecoverthepropertyfromHale SummaryofDeductiveReasoning Derivesitsconclusionbyreasoningfromthemajor i e general premisetotheminor i e particular premise Itsessenceisthesyllogism Legalproblemsolvinginthecivillawtraditionisakindofdeductivereasoning whichisbasedonrulesthecontentsofwhicharepositedpriortotheproblemstowhichtheymustbeapplied SummaryonDeductiveReasoning ForLegalDeductiveReasoning onemustfirstestablishtheRule Thismaybefromtheconstitution astatute anadministrativeregulation treaty executiveorder orothersourcesoflaw Second findthefacts Third conclude Case6 1 A MothersayssonXmaystayuptil10p m B SonYarguesheshouldbeabletostayupuntil10also sincetheyarebothherchildren C Thereforetheyshouldbetreatedalike Question whatreasoningisusedhere KeytoCase6 1 Analogyisaformofinductivereasoninginwhichyouuseinformationaboutaseriesofindividualcasestoreachaconclusionabouttheoutcomeofanothercase Case6 2 A MothersayssonXmaystayuptil10p m B SonYarguesheshouldbeabletostayupuntil10also sincetheyarebothherchildren thereforetheyshouldbetreatedalike C Mothersays nope Notavalidanalogy Question WHY KeytoCase6 2 Analogymaybeinvalid TipsforInductiveReasoning Therefore toreasonbyanalogy youmust 1 establishtherelevantbasepoint therelevantfactspluswhatactionshouldthenbetaken Ifthisistrue then 2 Thenonemustdescribethefactualrespectsinwhichthebasepointsituationandtheproblemsituationaresimilar ANALOGOUS orhowtheyaredifferent DISANALOGOUS 3 Third youjudgewhetherthefactualsimilaritiesorthefactualdifferencesinthetwoscenariosaremoreimportantunderthecircumstances Similarity Atleastonefeature identical Atleastonefeature different abcde and abcde arenotsimilar theyareidentical abcde and abcdf aresimilar abcde and abcfg aresimilar abcde and afghi aresimilar abcde and fghij arenotsimilar theyaredifferent Similarity example Johntooktheknife JohnattackedBillwiththeknife JohncausedBill sdeath Johnwashanged Jimtooktheknife JimattackedDickwiththeknife JimcausedDick sdeath Jimshallbehanged Difference example Johnwas25yearsold Billwasaninnocentgay Jimwas12yearsold Dickwasnotaninnocentgay hetriedtorapeJim Jimshallnotbehanged Case7 LegalInductiveReasoning Casea thedefendantknockedaplateoutofthehandsofplaintiff andthecourtfoundtherewasabattery anoffensivetouchingofsomethinglogicallyanextensionofplaintiff sperson Caseb thedefendantgrabbedthecollarofplaintiff ssuit andthecourtfoundtherewasabatteryoftheplaintiff FYI Inthesecases thecourtsemphasizedthatbatteryisadignitarytort andtheplaintiffcouldvalidlyfeelthathis herdignitywasbeinginvaded Case7 LegalInductiveReasoning Cont Casec thedefendantviolentlysmashedtheheadlightofacarinwhichplaintiffwassitting butthecourtsaidtherewasnobatteryofplaintiff becausetheplaintiff spersonoralogicalextensionofhispersonwasnotoffensivelytouched Cased thecourtfoundthatthrowingarockatabusinwhichplaintiffwassittingmighthavebeensomeothertort butitwasnotabatterytoplaintiff whowasnottouchedorharmedinanyway Case7 LegalInductiveReasoning Cont Indecidingwhetherthereisabatterywhendefendantangrilyslapstherumpofahorseonwhichplaintiffissitting onewouldsynthesizethefourcasesabovebyinductivereasoning How Generalizingapropositionthatwouldfitallthecases Case7 LegalInductiveReasoning Cont Onecouldconcludethatthegeneralpropositionisthat abatteryoccursifthedefendantintentionallycausesoffensiveorharmfulcontactwithplaintiff sperson orsomelogicalextensionofthatperson andthatalogicalextensionofapersonwouldbesomethinginclosecontactwiththeperson orsomethingsocloselyassociatedwiththeperson thathe shecouldreasonablyfeelthat bystrikingthatobject thedefendantwasinvadingtheplaintiff spersonaldignity Case7 LegalInductiveReasoning Cont Havingestablishedageneralpropositionoflawfromthesynthesisofaseriesofindividualcases nooneofwhichprobablystatesthepropositionassuch wethencanapplythepropositiontoourfactsbydeductivereasoning SummaryonInductiveReasoning Reachesitsconclusioninjusttheoppositemanner Worksbyassertingaseriesofminor i e particular premisestosupporttheconclusion amajor i e