证据法的理论基础和意义

201018（4）··“Evidence”and“evidencelaw”aretwoquitedistinctconcepts.“Evidence”generallyreferstothoseinputstodecisionmakingthatinfluenceitsoutcomeinwhat,tointroduceathirdconcept,isnormallyre-ferredtoasarationalmanner.IntheUnitedStates,“evidence”alsohasatechnicallegalmeaningtore-fertothetestimonyandexhibitsintroducedattrial,butthisisproblematic.IntheUnitedStates,factfindersmaytakeintoaccounttheirobservationsofwitnesses(“demeanor”),whichobviouslyis“evidence”inanyusefulsenseoftheterm,andmoredeeplynoobservationmaybeprocessedanddeliberateduponwithouttheuseofavaststorehouseofpreexistingconcepts,observations,anddecisionmakingstools(suchaslogic,abduction,utilities,andsoon).Ausefulconceptofevidencemustthusexpandconsiderablyfarbeyondthemere“trialinputs”theobservationsofwitnesstestimonyandexhibits.What“rational”meanshereisputtingalloftheinputsandcognitivecapabilitiestotheuseofdiscoveringasbestcanbedonethewaytheworldwasatsomepriortime,andthentoletrightsandobligationsbedeterminedcon-sistentlywiththepreexistingstateofaffairs.“Evidencelaw”,bycontrast,referstothemannerinwhichtheevidentiaryprocessisorganized,butobviouslytheorganizationoftheevidentiaryprocessiscontingentonboth“evidence”andthenatureof“rationality.”Thedomainofevidencelaw,then,extendstothetracesofthepastthatwecolloquiallyrefertoas“evidence,”themannerinwhichsuchtracesofthepastareprocessedandrelieduponinhumandecisionmaking,andtheregulationbylawoftheformalevidentiaryprocess.Evidencelawisthuscontin-gentupon,andmustaccommodate,atleastthreethings:Universaltruthsofthehumancondition,contin-gentaspectsofthenatureofgovernmentanditslegalsystem,andhighlyspecificpoliciestobepursuedinadditionoroppositiontothepursuitoftruth.Iwillsayawordabouteachoftheseinturn.UniversalTruths:Althoughmuchofhumancultureissociallydetermined,cognitivecapacitiesarenot.Howcapacitiesaredevelopedandemployedmaydiffer,buttheunderlyingepistemologicalcapacitiestoperceive,process,remember,andrelatewhatwasobservedarepartofthehumancondition.Obviously,theydifferoverindividualswithinsocieties,buttheyareuniversallypresentinallcompetentadults.Manyofthetoolsthathumansemploytoassistinunderstandingtheirenvironmentlikewiseareuniversal.Math-ematicsandlogicdonotvaryfromplacetoplace,nordodecisiontoolssuchasutilityfunctionsandcostTheTheoreticalFoundationsandImplicationsofEvidenceRonaldJ.AllenJohnHenryWigmoreProfessorofLaw,NorthwesternUniversityPresident,BoardofForeignAdvisors,EvidenceLawandForensicSciencesInstituteFellow,ProceduralLawResearchCenter,CUPLBeijing,ChinaJune,2010485··EvidenceScienceVol.18No.42010curves.Together,Iwillrefertotheseepistemologicalcapacitiesandformaltoolsasthe“toolsofrationali-ty.”Thesetoolsofrationalityarewhatpermithumanstounderstandandcontroltheirenvironment.Theyincludesuchthingsassimpledeductivereasoning,thecapacitytogeneralize,abductivereasoning(thesearchfortheexplanationofaseriesofdatapoints),anunderstandingofcauseandeffectandofnecessaryandsufficientconditions,andmanyotherthingsaswell.Theseissuescomprisethestudyofepistemolo-gy—thestudyofknowledge—andthelawofevidenceisinfactthelaw’sepistemology.Ishouldnotethatinsomediscussionsofthefoundationsofthelawofevidenceadistinctionismadebetweenprobabilitytheoryandepistemology.Thatmaybeausefuldistinctionforsomepurposes,butinmyopinionprobabili-tytheoryisjustoneofthetoolsofrationalitythatfacilitatepursuingepistemictasks.Theresurelyareculturalandsocialinfluencesoperatingonthebasictoolsofrationality,andatalllevels.Twoindividualsfromdifferentculturesmayexperiencethesameperceptualeventbutunderstanditcompletelydifferentlybasedontheirrespectivefamiliaritywiththetypeofeventinquestionandtheirbackgroundknowledge.Similarly,theassumptionsthatbeginlogicalprocessesmaydiffer,andboththesetsofcostsandbenefitsandtheirrelativeweightsmayvary,aswell.Iamlesssurethatthereisauniversalhumannaturebeyondtheepistemologicalcapacities,frankly,althoughmanythinkthatthereis.Thereismuchlosetalkaboutauniversalsenseofjusticeanduniver-salhumanrights,butthetwentiethcenturyisareproachtoanywhowouldsee“humannature”asbenefi-centorconcernedaboutthewelfareofstrangers.Perhaps,then,theeconomistsarecorrectinasensethatpeoplepursue,orshouldbeconceivedofaspursuing,theirownself-interest,howeverthoseinterestsareconceived.Obviously,peopledopursuetheirownfinancialandmedicalself-interestandthoseoftheirfamilies.Therecertainlyisawidespreaddesirefortheconditionsofapeacefullifewiththepossibilityofhumanflourishing,butitishardtoseethisasrestinguponuniversalsofthehumancondition.Notonlyisthetwentiethcenturyareproachtosuchaview,so,too,ismostofrecordedhistory.Andthetwenty-firstcenturyisofftoastartthatsuggestsnotmuchhaschangedfromthemillennium.AsIwillelaboratebelow,oneoftheprimarytasksofthelawofevidenceistoprocessanddigestthiselaboratesetofconsiderationsandcreateintheirlightasystemofdisputeresolutionthatservestheinter-estsofthecommunity.ContingenciesofGovernmentanditsLegalSystem:Althoughthereismuchthatiscommontohuman-ity,thewaysinwhichhumansorganizethemselvesvariesalmostinfinitely.Legalsystemsarecriticalcomponentsofgovern