第69章

ThetheoryismostexplicitlyworkedoutintheGrammarofAssent。Newmanexertsallhisskillinexpoundingaverysounddoctrine。Asamatteroffact，weforminnumerablejudgmentsbywhathecallsthe’illativesense’；thatistosay，notbyformalargument，butbyacomplexsystemof’implicit’reasonings。

’Logic，’ashesays，’doesnotreallyprove。Itenablesustojoinissuewithothers……itverifiesnegatively’；andfor’genuineproofinconcretematterwerequireanorganismmoredelicate，versatile，andelastic，thanverbalargumentation。’(244*)Logicisachainwhich’hangslooseatbothends，’(245*)forthefirstprinciplesmustbeassumed，andtheabstractconceptneverfitstheactualcomplexityofconcretefact。Bythe’illativesense，’again，wereachinnumerabletruths。WeholdthatEnglandisanisland，orthatthemanwhomweseeisourbrother，withafaithindistinguishablefromabsoluteconviction。Wegofurther；webelievethatafriendishonest，or，say，thatCaesarcrossedtheRubicon，withoutadmittingtheslightestscrupleofdoubt。Allknowledgewhateveroffactplainlyimpliessomethingdifferentfromformallogic；

and，sofar，theonlyquestionseemstobewhysopalpableatruthneedssoelaborateandgracefulanexposition。TheanswerisindicatedbythepolemicagainstLocke。Lockehadproposed，asatestofaloveoftruth，therefusaltoholdanyproposition，withagreaterassurancethantheproofsitisbuiltonwillwarrant。’(246*)ThestatementseemstobenotonlyunassailablebutinconformitywithNewman’sdoctrine。ShouldwebelieveEnglandtobeanisland？WhenJuliusCaesarlanded，itwasnotproved；andhewouldhavebeenwrongtobecertain。Whendiditbecomerighttobecertain？Surelyatwhatevermomentitwasadequatelyproved。Itisneversoprovedthattodenyitwouldbeself-contradictory，butbythistimeitisasmuchprovedasanyfactcanbeproved。Lockewouldsimplyjustifyhimselfbysayingthatinthiscaseour’assurance’doesnotexceedthe’proofsonwhichitisbuilt。’Theapproximationtodemonstrationisindefinitelyclose，thoughneverabsolute，andthedifferencebecomestoosmalltobeperceptible。Adifficultyemergesonlyifweatonceadmittherightnessofbeliefanddenythesufficiencyoftheevidence。

Newman，havingshownthatwebelieveinconcretetruthsnotprovedbyabstractlogic，arguesthatwealsoassumemanytruthsnotprovedevenbysufficientempiricalevidence。WehavewhatLockecalleda’surplusageofassurance。’Thefact，again，isundeniable。Webelieveimplicitlyincountlessthingsuponinsufficientevidence。This，asLockewouldadd，isonemainexplanationoftheprevalenceoferror，andalsoaproofthaterrormaybeinnocent。Itisadutytobecandid；itcannotbeadutytoberight。Wemustlistentoreason；buttheeffectofreasoningmustdependupontheconstitutionofourminds，andthevariousbeliefswithwhichtheyarealreadystored。NowtoNewmanthisdoctrinealwaysseemstobesceptical。Itamountstothe’liberalising’viewthatallcreedsareequallygoodifonlytheybeequallysincere。Hencehelaysstressuponthedoctrinethat’assent’isavolitionalaswellasan’intellectualact。’Itisourdutytoobeythereason；andwhenthe’illativesense’

declaresthetruthofaproposition，weareboundtoan’activerecognition’ofthetruth。(247*)Locke，onthecontrary，holdsthatifwelistentoreason，theassentfollowsautomaticallybyanon-voluntaryact。

OnNewman’sshowing，anelementofvolitionintrudesintologic。Beliefbelongstoactionaswellastopurespeculation。

’Toactyoumustassume，’hesays，’andthatassumptionisfaith。’(248*)Ifactinguponanhypothesisisthesamethingasbelievingthetruthtobedemonstrated，thisleadstoasingularresult。Ajudge，saysNewman，actsupontheassumptionthatacriminal’sguiltisproved。(249*)Yet，asitisnevermathematicallydemonstrated，hehasa’surplusageofassurance。’

Thejudgemaybeofopinionthattheprisoner’sguiltishighlyprobableandyetbeboundtoacquit。Ishetobelievethattheprisoner’sinnocenceisdemonstrated？Thecasereallyshowstheopposite：simplythataswehavetoactuponprobabilities，wearenottheless，butthemore，boundtoguardagainsttheillusionthattheyarecertainties。Ateverymomentandineveryrelationofourlives，weareforcedtoactuponimperfectknowledge。Theobviousinferenceisthatweareboundtokeepinmindthatitisimperfect