Trolley problem | Definition, Variations, Arguments, Solutions ...

Trolley problem, in moral philosophy, a question first posed by the contemporary British philosopher Philippa Foot as a qualified defense of the doctrine of ... Trolleyproblem TableofContents Trolleyproblem Introduction&TopQuestions FastFacts TopQuestions Howcanthetrolleyproblembeusedtocritiqueutilitarianism? RelatedContent More Contributors ArticleHistory Home Philosophy&Religion EthicalIssues Trolleyproblem ethics Actions Cite verifiedCite Whileeveryefforthasbeenmadetofollowcitationstylerules,theremaybesomediscrepancies. Pleaserefertotheappropriatestylemanualorothersourcesifyouhaveanyquestions. SelectCitationStyle MLA APA ChicagoManualofStyle CopyCitation Share Share Sharetosocialmedia Facebook Twitter URL https://www.britannica.com/topic/trolley-problem GiveFeedback Feedback Corrections?Updates?Omissions?Letusknowifyouhavesuggestionstoimprovethisarticle(requireslogin). 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SelectCitationStyle MLA APA ChicagoManualofStyle CopyCitation Share Share Sharetosocialmedia Facebook Twitter URL https://www.britannica.com/topic/trolley-problem Feedback By BrianDuignan • EditHistory TableofContents RelatedTopics: ethics doctrineofdoubleeffect ...(Showmore) Seeallrelatedcontent→ TopQuestionsWhatisthetrolleyproblem?Oneoftheoriginalversionsofthetrolleyproblemisthis:Whydoesitseempermissibleorevenobligatorytokillonetrackworkertosavefiveothersbyredirectingarunawaytrolleybutgrosslywrongtoexecuteaninnocentpersontosavefivehostagesfromaviolentmob?Exploreotherversionsofthetrolleyproblem.Wheredidthetrolleyproblemoriginate?Thetrolleyproblemoriginatedina1967essaybytheBritishphilosopherPhilippaFoot,whouseditinconstructingapartialdefenseofthedoctrineofdoubleeffectandofherthesisthatpositiveduties(dutiestoperformacertainaction)areintuitivelylessimportantthannegativeduties(dutiesnottoperformacertainaction).Whyisthetrolleyproblemimportant?Thetrolleyproblemisimportantbecauseversionsofithavebeenusedtoexplorethevalidityandrangeofapplicationofthedoctrineofdoubleeffectandthedistinctionbetweendoingharmandallowingharm.Ithasalsobeenused toclarifythelimitationsofboth deontological (rule-based)and consequentialist (e.g., utilitarian)approachesin appliedethics.Howcanthetrolleyproblembeusedtocritiqueutilitarianism?Utilitarianism holdsthatanactionisrightifitmaximizeshappinessfortheagentandforeveryoneaffected.Accordingly,inthetrolleyproblem,itwouldberight forthetrolleydriver toredirecttherunawayvehiclesothatonlyonepersoniskilledinsteadoffive;itwouldalsoberightforamagistratetoexecuteoneinnocentpersontosavefiveothers.Bymostpeople’sintuitions,however,thefirstactionwouldberightandthesecondwouldbewrong.Becauseutilitarianismseemsunabletorationallyreconcilethoseintuitions,thetrolleyproblemhasbeenusedtocritiqueit.Trolleyproblem,inmoralphilosophy,aquestionfirstposedbythecontemporaryBritishphilosopherPhilippaFootasaqualifieddefenseofthedoctrineofdoubleeffectandasanargumentforherthesisthatnegativedutiescarrysignificantlymoreweightinmoraldecisionmakingthanpositiveduties.Thetrolleyproblem,asitcametobeknown,wasfirstidentifiedassuchbytheAmericanphilosopherJudithJarvisThomson,whoseessay“Killing,LettingDie,andtheTrolleyProblem”(1976)spawnedavastacademicliteratureonthetopic.Theproblemimmediatelysuggestedabroaderapplicationofthedoctrineofdoubleeffectbeyondthemoralityofabortion,acommoncontextofmoderndiscussionsofthedoctrine,andpromptedavarietyofproposedsolutions,manybasedonnovelvariationsofthequestiondesignedtolendinsightintoFoot’soriginalformulationandtofurtherexplorethephilosophicalissuesitraises.Theproblemappealstobothconsequentialist(utilitarian)anddeontological(rule-orduty-based)moralintuitionsbutdoesnotadmitofanysimplesolutionfromeitherperspective.Inheressay“TheProblemofAbortionandtheDoctrineoftheDoubleEffect”(1967),Footdefinedthedoctrineofdoubleeffectintermsofthedistinctionbetweenwhatapersonstrictly(directly,explicitly)intendsastheendandthemeansofacontemplatedactionandwhataperson“obliquely”(indirectly)intendsasaforeseenconsequenceoftheactionbutnotasanendorameans.Indeed,theforeseenconsequencemaybecompletelyundesiredandregrettable.“By‘thedoctrineofthedoubleeffect’,”sheexplained,“Imeanthethesisthatitissometimespermissibletobringaboutbyobliqueintentionwhatonemaynotdirectlyintend.”Somewhatmorespecifically,thedoctrineis“thethesisthatsometimesitmakesadifferencetothepermissibilityofanactioninvolvingharmtoothersthatthisharm,althoughforeseen,isnotpartoftheagent’sdirectintention.”Inthe20thcenturysomemoraltheorists,inparticularthoseassociatedwiththeRomanCatholicChurch,invokedoneoranotherversionofthedoctrinetodistinguishbetweencasesinwhichanactiontakentosavethelifeofapregnantwomanforeseeablyresultsinthedeathofthefetus—e.g.,theremovalofacancerousuterus—andcasesinwhichthefetusiskilledastheonlymeansofsavingapregnantwoman’slife—e.g.,acraniotomyperformedonafetus(orinfant)inbreechposition(theexamplepresupposesamedicalcontextinwhichacesareansectionisnotpossible).Catholictheoristsgenerallyregardedactionssuchasthehysterectomyasmorallypermissibleandactionssuchasthecraniotomyasmorallywrong,becausethedeathofthefetusisonlyobliquelyintendedintheformercasebutisdirectlyintendedinthelatter.Criticsofthedoctrineofdoubleeffect,ofwhichthereweremany,tendedtodismissthedistinctionitdrewasspeciousandtocharacterizethedoctrine’sapplicationtosuchextremecasesasasophisticalattempttojustifytheCatholicchurch’snearlyblanketoppositiontoabortion.Thedoctrineofdoubleeffect,asFootherselfpointedout,isvulnerabletocounterexamplesifitisformulatedtoobroadlyastheprinciplethatactionsthathaveforeseeablebadconsequencesaremorallypermissibleaslongasthoseconsequencesarenotdirectlyintended—i.e.,aslongastheyareintendedonlyobliquely.Forexample,merchantswhosellascookingoilaconcoctionthattheyknowtobepoisonous,resultinginthedeathsofmanyinnocentpeople,arenotfreeofblamemerelybecausetheyonlyobliquelyintendtheircustomers’deaths,theirdirectintentionbeingonlytomakemoney.Nevertheless,accordingtoFoot,thedistinctionbetweendirectlyandobliquelyintendedconsequencesshouldbetakenseriously,becauseitisusefulinexplainingthedifferencebetweencertaincasesinwhichitwouldbemorallypermissible(ifnotobligatory)toperformanactionthatoneknowswillbringaboutaninnocentperson’sdeathandparallelcasesinwhichperformingsuchanactionwouldbeclearlymorallywrong.Absentanexplanationbasedonthedoctrineofdoubleeffectorsomeotherprinciple,Footargued,actionsofthelattersortwouldhavetobeacceptedasatleastmorallypermissible,despitemostpeople’sstrongintuitionstothecontrary.Asanexampleofacaseofthefirstsort,involvinganactionthatforeseeablyresultsinaninnocentperson’sdeath,Footimaginedthedilemmaof“thedriverofarunawaytramwhichhecanonlysteerfromonenarrowtrackontoanother;fivemenareworkingononetrackandonemanontheother;anyoneonthetrackheentersisboundtobekilled.”Ifaskedwhatthedrivershoulddo,“weshouldsay,withouthesitation,thatthedrivershouldsteerforthelessoccupiedtrack,”accordingtoFoot.(Foot’sdescriptionofthisexamplehasbeengenerallyinterpretedtomeanthatthetramistravelingdownthetrackonwhichfivepeopleareworkingandwillkillthosepeopleunlessthedriverswitchestothetrackonwhichonepersonisworking,inwhichcasethetramwillkillonlythatperson.)Footthencomparedthissituationtoaparallelcase,whichshedescribedasfollows:“Supposethatajudgeormagistrateisfacedwithriotersdemandingthataculpritbefoundforacertaincrimeandthreateningotherwisetotaketheirownbloodyrevenge”onfivehostages.“Therealculpritbeingunknown,thejudgeseeshimselfasabletopreventthebloodshedonlybyframingsomeinnocentpersonandhavinghimexecuted.”Inbothcases,shenotes,“theexchangeissupposedtobeoneman’slifeforthelivesoffive.”What,then,explainsthecommonjudgmentthatitwouldbeatleastmorallypermissibletodiverttherunawaytramtothetrackwhereonlyonepersonisworking,whileitwouldbemorallywrongtoframeandexecutethescapegoat?Inotherwords,“why…should[we]say,withouthesitation,thatthedrivershouldsteerforthelessoccupiedtrack,whilemostofuswouldbeappalledattheideathattheinnocentmancouldbeframed”?Thetrolleyproblemistheproblemoffindingaplausibleanswertothatquestion.Foot’sfirst,provisionalsolutiontotheproblemistosaythattherelevantdifferenceineachpairofcasescanbearticulatedintermsofthedoctrineofdoubleeffect:thetramdriveronlyobliquelyintendsthedeathofonetrackworker,whilethejudgedirectlyintendsthedeathofthescapegoat—acontrastmadevividbyFoot’sobservationthat,shouldthescapegoatprovehardtohang,thejudgewouldbeforcedtokillhiminsomeotherway,butthetramdriverwouldnotlookforanotherwaytokillthetrackworkerifthelattersomehowsurvivedbeingrunoverbythetram.Thedoctrineofdoubleeffectthusexplainsthecontrastinmoralassessmentsofthecasesbymakingclearthat“itisonethingtosteertowardssomeoneforeseeingthatyouwillkillhimandanothertoaimathisdeathaspartofyourplan.”Similarproblemsinvolvingdrasticallydifferentmoralassessmentsofparallelcasesarefairlyeasytoimagineandseemequallyamenabletosolutionthroughthedoctrineofdoubleeffect.Forexample:Weareabouttogiveapatientwhoneedsittosavehislifeamassivedoseofacertaindruginshortsupply.Therearrive,however,fiveotherpatientseachofwhomcouldbesavedbyone-fifthofthatdose.Wesaywithregretthatwecannotspareourwholesupplyofthedrugforasinglepatient,justasweshouldsaythatwecouldnotsparethewholeresourcesofawardforonedangerouslyillindividualwhenambulancesarrivebringinginvictimsofamultiplecrash.Wefeelboundtoletonemandieratherthanmanyifthatisouronlychoice.Whythendowenotfeeljustifiedinkillingpeopleintheinterestsofcancerresearchortoobtain,letussay,sparepartsforgraftingontothosewhoneedthem?Althoughsuchexamplesappeartoshowthatthedoctrineofdoubleeffectisvalid,Footultimatelyconcludedthattheyarebetterexplainedthroughadistinctionbetweenwhatshecalled“positive”and“negative”duties.Sheofferedanapproximatedefinitionofapositivedutyasamoralobligationtoaidorbenefitothersinagivenwayinsituationswheretheyareinneedofhelp.(Footpurposefullyemployedthenotionofpositivedutyinabroadsensetoencompassactsofcharitythatwouldordinarilybeconsideredsupererogatory—i.e.,laudableorcommendablebutnotobligatory.)Anegativeduty,incontrast,isapproximatelydefinedasamoralobligationnottoharmorinjureothersinagivenway.Footcontendedthatthisdistinctionofdutiescouldaccountforthecontrastinmoralintuitionsinallvariantsofthetramproblemexplainedbythedoctrineofdoubleeffect—andinothervariantsoftheproblemthatthedoctrineseemsunabletohandle—providedthatnegativedutiesareunderstoodtosignificantlyoutweighpositivedutiesincaseswherethetwoconflict(i.e.,wherethedutiesprescribeconflictingactions).Becausethisassumptionhelpstoexplainmostpeople’smoralintuitionsinthecontrastingpairsofcases,andthustoofferaplausiblesolutiontothetramproblem,thesolutionitselfconstitutesanargumentinfavouroftheviewthatnegativedutiesaremoreimportantthanpositiveones.Thesolutionalsoassumes,andthusdemonstrates,thatincasesofconflictingdutiesofthesamekind(positiveornegative),thedutythatoughttobecarriedoutistheonethateithermaximizesaidorminimizesharm.AccordingtoFoot,thetramdriverfacesaconflictbetweenthenegativedutynottokillfivetrackworkersandthenegativedutynottokillone.Becausethecircumstancesmakeitimpossibletoactonbothduties,thedrivershouldcarryoutthedutythatentailstheleastnumberofdeaths,aconclusionthataccordswithmostpeoples’intuitions.Inthecaseofthescapegoat,thejudgefacesaconflictbetweenthepositivedutytosavethelivesoffivepeopleandthenegativedutynottokillone.Theintuitionofmostpeoplethatthejudgeshouldnotcarryouttheexecutionisexplainedbytheassumptionthatthenegativedutyismoreimportantthanthepositiveone.SincethepublicationofFoot’sessay,manyanalysesofthetrolleyproblem,asThomsoncalledit,havebeenoffered—includingseveralthatdisputeherdefenseofthedoctrineofdoubleeffectorherthesisofpositiveandnegativeduties—andabroadrangeofconclusionshavebeendrawnfromit.Inheressays“Killing,LettingDie,andtheTrolleyProblem”(1976)and“TheTrolleyProblem”(1985),ThomsonintroducedprovocativevariantsoftheoriginalscenariothatseemedtoundermineFoot’sduty-basedanalysis.Inoneofthem,thedriverofthetrolleyfaintsafterrealizingthatthetrolley’sbrakeshavefailed,andabystanderontheground,understandingtheemergency,noticesaswitchthatcouldbethrowntodivertthetrolleyontotheone-workertrack.Mostpeoplewouldagreethatitwouldbeatleastmorallypermissibleforthebystandertothrowtheswitch.OnFoot’sanalysis,thebystanderwouldtherebyviolateanegativedutynottokilloneperson.Ifthebystanderdoesnothing,however,thenegativedutynottokillfivepeoplewouldnotbeviolated,since,indoingnothing,thebystanderwouldnotbeengaged(inanyreasonablesense)inactivekilling—aswouldthedriverofthetrolley,whoisunderstoodto(involuntarily)drivethevehicleintotheworker(s)inbothFoot’saccountandThomson’s.Atmost,thebystanderwouldbeviolatingapositivedutytosavefivepeople.Foot’sanalysis,therefore,incorrectlypredictsthatmostpeoplewouldconsideritmorallywrongforthebystandertothrowtheswitch.Thomsonalsoofferedasimilarexampleinwhichthe“bystander”isapassengeronthetrolley,wholikewisewouldnotbedrivingthetrolleyintothefiveworkersifhedidnothing.Anothermuch-discussedvariantbyThomsoninvolvestwobystanderswhowitnesstheemergencyfromafootbridgeoverthetrackleadingtothefiveworkers.Oneofthem,understandingthatthetrolleycanbestoppedonlyifaheavyobjectisthrowninitspath,pushestheother,a“fatman,”offthebridgeandontothetrack,therebyhaltingthetrolleyandsavingthefiveworkersbut,ofcourse,killingthefatman.Ifthepushingtakesplace,thepusherwillhaveviolatedanegativedutynottokilloneperson.If,ontheotherhand,thebystanderdoesnothing,noviolationofanegativedutynottokillfivepeoplewouldoccur(becausethebystanderwouldnothaveengagedinanyactivekilling);atmost,thebystanderwillhaveviolatedapositivedutytosavefivepeople.AsThomsonnotedinalateressay,“TurningtheTrolley”(2008),thecaseofthefatmanissimilartothecaseinwhichthejudgeframesandexecutesascapegoattosavefivehostagesandthecaseinwhichasurgeonkillsahealthyperson(againstthatperson’swill)andtransplantsthehealthyperson’svitalorgansintofivepatientswhoneedthemtosurvive(compareFoot’sexampleof“killingpeopleintheinterestsofcancerresearchortoobtain…sparepartsforgraftingontothosewhoneedthem”).AlthoughFoot’sduty-basedanalysiscorrectlypredictsthatmostpeoplewouldconsideritmorallywrongtopushthefatmanoffthebridge,itsapparentfailuretoaccountformostpeople’smoralintuitionsinthecasesinvolvingthebystanderonthegroundandthepassengeronthetrolleyindicatesthattheremustbeother,heretoforeunnoticed,differencesbetweenthecasesinwhichtheactiontakenseemspermissibleandthecasesinwhichitseemswrong.Likewise,theremustbeothersimilaritiesbetweenthecasesinwhichtheactionseemswrongandothersimilaritiesbetweenthecasesinwhichitseemspermissible.In“Killing,LettingDie,andtheTrolleyProblem,”Thomsontentativelysuggestedthattherelevantsimilaritiesbetweenthe“wrong”casesareeither:(1)thepersonkilledhasmoreofaclaimonabenefitorgoodofwhichheorsheisdeprivedormoreofaclaimagainsttheharmthatheorshesuffers,thandotheotherperson(s)involved,or(2)theactionimmediatelytakeninvolvesdoingsomethingtothepersondeprivedorharmedratherthandoingsomethingtosomeotherthing,whichthenresultsinthatpersonbeingdeprivedorharmed.Thus,Foot’sexamplesoftheexecutedscapegoatandthepersonkilledforbodyparts,aswellasThomson’sexampleofthefatmanandtheinvoluntarydonorofvitalorgans,allexhibitfeature2,whilethetwosurgicalcasesexhibitbothfeature2andfeature1—thelatterbecausethevictimsinthesurgicalcasesobviouslyhaveadecisiveclaimontheirownbodyparts.Incontrast,theoriginaltrolleyproblem,aswellasthecasesofthebystanderonthegroundandthepassengerinthetrolley,exhibitneitherfeature.Thomson’saforementionedessays,writtenoverthecourseofmorethanthreedecades,containseveralothervariantsandanalysesofthetrolleyproblem.(Interestingly,inher2008essay,“TurningtheTrolley,”Thomsonarguedthatthecommonintuitionthatitwouldbepermissibleforthebystanderonthegroundtodivertthetrolleyismistaken.)Theacademicliteraturethatherworkhasinspiredencompassesdescriptiveaswellasnormativeaccountsandcontributionsfrompsychologists,physiologists,andlegalscholarsaswellasphilosophers.Somewhatsimplifiedversionsoftheproblemhavealsobeenpresentedinnonacademicpublications.BrianDuignan