Forthatmatter，thereisabsolutelynoneedtobealarmedatthefactthatthestageofknowledgewhichwehavenowreachedisaslittlefinalasallthathaveprecededit。Italreadyembracesavastmassofjudgmentsandrequiresverygreatspecialisationofstudyonthepartofanyonewhowantstobecomeconversantwithanyparticularscience。Butamanwhoappliesthemeasureofgenuine，immutable，finalandultimatetruthtoknowledgewhich，byitsverynature，musteitherremainrelativeformanygenerationsandbecompletedonlystepbystep，orwhich，asincosmogony，geologyandthehistoryofmankind，mustalwayscontaingapsandbeincompletebecauseoftheinadequacyofthehistoricalmaterial——suchamanonlyprovestherebyhisownignoranceandperversity，eveniftherealthingbehinditallisnot，asinthiscase，theclaimtopersonalinfallibility。Truthanderror，likeallthought-conceptswhichmoveinpolaropposites，haveabsolutevalidityonlyinanextremelylimitedfield，aswehavejustseen，andasevenHerrDühringwouldrealiseifhehadanyacquaintancewiththefirstelementsofdialectics，whichdealpreciselywiththeinadequacyofallpolaropposites。Assoonasweapplytheantithesisbetweentruthanderroroutsideofthatnarrowfieldwhichhasbeenreferredtoaboveitbecomesrelativeandthereforeunserviceableforexactscientificmodesofexpression，andifweattempttoapplyitasabsolutelyvalidoutsidethatfieldwereallyfindourselvesaltogetherbeaten:bothpolesoftheantithesisbecometransformedintotheiropposites，truthbecomeserroranderrortruth。Letustakeasanexamplethewell-knownBoyle’slaw。Accordingtoit，ifthetemperatureremainsconstant，thevolumeofagasvariesinverselywiththepressuretowhichitissubjected。
Regnaultfoundthatthislawdoesnotholdgoodincertaincases。Hadhebeenaphilosopherofrealityhewouldhavehadtosay:Boyle’slawismutable，andishencenotagenuinetruth，henceitisnotatruthatall，henceitisanerror。ButhadhedonethishewouldhavecommittedanerrorfargreaterthantheonethatwascontainedinBoyle’slaw;hisgrainoftruthwouldhavebeenlostsightofinasand-hilloferror;hewouldhavedistortedhisoriginallycorrectconclusionintoanerrorcomparedwithwhichBoyle’slaw，alongwiththelittleparticleoferrorthatclingstoitwouldhaveseemedliketruth。ButRegnault，beingamanofscience，didnotindulgeinsuchchildishness，butcontinuedhisinvestigationsanddiscoveredthatingeneralBoyle’slawisonlyapproximatelytrue，andinparticularlosesitsvalidityinthecaseofgaseswhichcanbeliquefiedbypressure，namely，assoonasthepressureapproachesthepointatwhichliquefactionbegins。Boyle’slawthereforewasprovedtobetrueonlywithindefinitelimits。Butisitabsolutelyandfinallytruewithinthoselimits？Nophysicistwouldassertthat。Hewouldmaintainthatitholdsgoodwithincertainlimitsofpressureandtemperatureandforcertaingases;andevenwithinthesemorerestrictedlimitshewouldnotexcludethepossibilityofastillnarrowerlimitationoralteredformulationastheresultoffutureinvestigations。*2Thisishowthingsstandwithfinalandultimatetruthsinphysics，forexample。
Reallyscientificworkstherefore，asarule，avoidsuchdogmaticallymoralexpressionsaserrorandtruth，whiletheseexpressionsmeetuseverywhereinworkssuchasthephilosophyofreality，inwhichemptyphrasemongeringattemptstoimposeitselfonusasthemostsovereignresultofsovereignthought。
But，anaivereadermayask，wherehasHerrDühringexpresslystatedthatthecontentofhisphilosophyofrealityisfinalandevenultimatetruth{D。Ph。2}？Where？Well，forexample，inthedithyrambonhissystempage13，apartofwhichwecitedinChapterII。Orwhenhesays，inthepassagequotedabove:Moraltruths，insofarastheirultimatebasesareunderstood，claimthesamevalidityasmathematicalinsights。
AnddoesnotHerrDühringassertthat，workingfromhisreallycriticalstandpoint{D。Ph。404}andbymeansofthoseresearchesofhiswhichgototherootofthings{200}，hehasforcedhiswaythroughtotheseultimatefoundations，thebasicschemata，andhasthusbestowedfinalandultimatevalidityonmoraltruths？Or，ifHerrDühringdoesnotadvancethisclaimeitherforhimselforforhisage，ifheonlymeanttosaythatperhapssomedayinthedarkandnebulousfuturefinalandultimatetruthsmaybeascertained，ifthereforehemeanttosaymuchthesame，onlyinamoreconfusedway，asissaidby“mordantscepticism“and“hopelessconfusion“