Thereis，however，onemethodofexhibitingaprioritheabsolutedutyofTruth，whichwemustnotoverlook；
as，ifitbevalid，itwouldseemthattheexceptionsandqualificationsabovementionedhavebeenonlyadmittedbyCommonSensefrominadvertenceandshallownessofthought。
Itissaidthatifitwereoncegenerallyunderstoodthatlieswerejustifiableundercertaincircumstances，itwouldimmediatelybecomequiteuselesstotellthelies，becausenoonewouldbelievethem；andthatthemoralistcannotlaydownarulewhich，ifgenerallyaccepted，wouldbesuicidal。
Tothisthereseemtobethreeanswers。Inthefirstplaceitisnotnecessarilyanevilthatmen’sconfidenceineachother’sassertionsshould，undercertainpeculiarcircumstances，beimpairedordestroyed:itmayevenbetheveryresultwhichweshouldmostdesiretoproduce:e。g。itisobviouslyamosteffectiveprotectionforlegitimatesecretsthatitshouldbeuniversallyunderstoodandexpectedthatthosewhoaskquestionswhichtheyhavenorighttoaskwillhaveliestoldthem:nor，again，shouldweberestrainedfrompronouncingitlawfultomeetdeceitwithdeceit，merelybythefearofimpairingthesecuritywhichroguesnowderivefromtheveracityofhonestmen。Nodoubttheultimateresultofgeneralunveracityunderthecircumstanceswouldbeastateofthingsinwhichsuchfalsehoodswouldnolongerbetold:butunlessthisultimateresultisundesirable，theprospectofitdoesnotconstituteareasonwhythefalsehoodsshouldnotbetoldsolongastheyareuseful。But，secondly，sincethebeliefsofmeningeneralarenotformedpurelyonrationalgrounds，experienceshowsthatunveracitymaylongremainpartiallyeffectiveundercircumstanceswhereitisgenerallyunderstoodtobelegitimate。Weseethisinthecaseofthelaw-courts。Forthoughjurymenareperfectlyawarethatitisconsideredthedutyofanadvocatetostateasplausiblyaspossiblewhateverhehasbeeninstructedtosayonbehalfofanycriminalliemaydefend，stillaskilfulpleadermayoftenproduceanimpressionthathesincerelybelieveshisclienttobeinnocent:anditremains，aquestionofcasuistryhowfarthiskindofhypocrisyisjustifiable。But，finally，itcannotbeassumedascertainthatitisneverrighttoactuponamaximofwhichtheuniversalapplicationwouldbeanundoubtedevil。Thisassumptionmayseemtobeinvolvedinwhatwaspreviouslyadmittedasanethicalaxiom，thatwhatisrightformemustberightfor`allpersonsundersimilarconditions’。[1]
Butreflectionwillshowthatthereisaspecialcasewithintherangeoftheaxiominwhichitsapplicationisnecessarilyself-limiting，andexcludesthepracticaluniversalitywhichtheaxiomappearstosuggest:i。e。wheretheagent’sconditionsinclude1theknowledgethathismaximisnotuniversallyaccepted，and2areasonedconvictionthathisactwillnottendtomakeitso，toanyimportantextent。Forinthiscasetheaxiomwillpracticallyonlymeanthatitwillberightforallpersonstodoastheagentdoes，iftheyaresincerelyconvincedthattheactwillnotbewidelyimitated；andthisconvictionmustvanishifitiswidelyimitated。Itcanhardlybesaidthattheseconditionsareimpossible: