This，however，isnonethelessahypothesistrulyscientificinconception，andinthespeculationstowhichitleadsuswearestillsureofdealingwithviewsthatadmitatleastofdefiniteexpressionandtreatment。Inotherwords，thoughourstudyofthevisibleuniversehasledustotherecognitionofakindofunseenworldunderlyingtheworldofthingsthatareseen，yetconcerningtheeconomyofthisunseenworldwehavenotbeenledtoentertainanyhypothesisthathasnotitspossiblejustificationinourexperiencesofvisiblephenomena。
Wearenowcalledupon，followinginthewakeofouresteemedauthors，toventureonadifferentsortofexploration，inwhichwemustcutloosealtogetherfromourmooringsintheworldofwhichwehavedefiniteexperience。Weareinvitedtoentertainsuggestionsconcerningthepeculiareconomyoftheinvisibleportionoftheuniversewhichwehavenomeansofsubjectingtoanysortoftestofprobability，eitherexperimentalordeductive。Thesesuggestionsare，therefore，nottoberegardedasproperlyscientific；but，withthiswordofcaution，wemayproceedtoshowwhattheyare。
Comparedwiththelifeanddeathofcosmicalsystemswhichwehaveheretoforecontemplated，thelifeanddeathofindividualsofthehumanracemayperhapsseemasmallmatter；yetbecauseweareourselvesthemenwholiveanddie，thesmalleventisofvastlygreaterinteresttousthanthegrandseriesofeventsofwhichitispartandparcel。Itisnaturalthatweshouldbemoreinterestedintheultimatefateofhumanitythaninthefateofaworldwhichisofnoaccounttoussaveasourpresentdwelling-place。Whetherthehumansoulistocometoanendornotistousamoreimportantquestionthanwhetherthevisibleuniverse，withitsmatterandenergy，istobeabsorbedinaninvisibleether。Itisindeedonlybecauseweareinterestedintheformerquestionthatwearesocuriousaboutthelatter。Ifwecoulddissociateourselvesfromthematerialuniverse，ourhabitat，weshouldprobablyspeculatemuchlessaboutitspastandfuture。Wecareverylittlewhatbecomesoftheblackballoftheearth，afteralllifehasvanishedfromitssurface；or，ifwecareatallaboutit，itisonlybecauseourthoughtsaboutthecareeroftheeartharenecessarilymixedupwithourthoughtsaboutlife。Henceinconsideringtheprobableultimatedestinyofthephysicaluniverse，ourinnermostpurposemustbetoknowwhatistobecomeofallthisrichandwonderfullifeofwhichthephysicaluniverseisthetheatre。Hasitallbeendeveloped，apparentlyatalmostinfinitewasteofeffort，onlytobeabolishedagainbeforeithasattainedtocompleteness，ordoesitcontainorsheltersomeindestructibleelementwhichhavingdrawnsustenanceforawhilefromthesenselessturmoilofphysicalphenomenashallstillsurvivetheirfinaldecay？Thisquestioniscloselyconnectedwiththetime-honouredquestionofthemeaning，purpose，ortendencyoftheworld。Inthecareeroftheworldislifeanend，orameanstowardanend，oronlyanincidentalphenomenoninwhichwecandiscovernomeaning？
Contemporarytheologiansseemgenerallytobelievethatonenecessaryresultofmodernscientificinquirymustbethedestructionofthebeliefinimmortallife，sinceagainsteverythoroughgoingexpounderofscientificknowledgetheyseektohurlthechargeof“materialism。“Theirdoubts，however，arenotsharedbyourauthors，thoroughmenofscienceastheyare，thoughtheirmodeofdealingwiththequestionmaynotbesuchaswecanwelladopt。Whileupholdingthedoctrineofevolution，andalltheso-called“materialistic“viewsofmodernscience，theynotonlyregardthehypothesisofafuturelifeasadmissible，buttheyevengosofarastopropoundaphysicaltheoryastothenatureofexistenceafterdeath。Letusseewhatthisphysicaltheoryis。
Asfarasthevisibleuniverseisconcerned，wedonotfindinitanyevidenceofimmortalityorofpermanenceofanysort，unlessitbeinthesumofpotentialandkineticenergiesonthepersistencyofwhichdependsourprincipleofcontinuity。Inordinarylanguage“thestarsintheircourses“serveassymbolsofpermanence，yetwehavefoundreasontoregardthemasbuttemporaryphenomena。So，inthelanguageofourauthors，“ifwetaketheindividualman，wefindthatheliveshisshorttaleofyears，andthatthenthevisiblemachinerywhichconnectshimwiththepast，aswellasthatwhichenableshimtoactinthepresent，fallsintoruinandisbroughttoanend。Ifanygermorpotentialityremains，itiscertainlynotconnectedwiththevisibleorderofthings。“Inlikemannerourraceisprettysuretocometoanendlongbeforethedestructionoftheplanetfromwhichitnowgetsitssustenance。Andinourauthorsopinioneventheuniversewillbyandbybecome“oldandeffete，nolesstrulythantheindividual:itisagloriousgarmentthisvisibleuniverse，butnotanimmortalone；wemustlookelsewhereifwearetobeclothedwithimmortalityaswithagarment。“
Itisatthispointthatourauthorscallattentionto“theapparentlywastefulcharacterofthearrangementsofthevisibleuniverse。“Thefactisonewhichwehavealreadysufficientlydescribed，butweshalldowelltoquotethewordsinwhichourauthorsrecurtoit:“Allbutaverysmallportionofthesun’sheatgoesdaybydayintowhatwecallemptyspace，anditisonlythisverysmallremainderthatismadeuseofbythevariousplanetsforpurposesoftheirown。Cananythingbemoreperplexingthanthisseeminglyfrightfulexpenditureoftheverylifeandessenceofthesystem？Thatthisvaststoreofhigh-classenergyshouldbedoingnothingbuttravellingoutwardsinspaceattherateof188，000milespersecondishardlyconceivable，especiallywhentheresultofitistheinevitabledestructionofthevisibleuniverse。“
Pursuingthisteleologicalargument，itissuggestedthatperhapsthisapparentwasteofenergyis“onlyanarrangementinvirtueofwhichouruniversekeepsupamemoryofthepastattheexpenseofthepresent，inasmuchasallmemoryconsistsinaninvestitureofpresentresourcesinordertokeepaholduponthepast。“RecourseishadtotheingeniousargumentinwhichMr。
Babbageshowedthat“ifwehadpowertofollowanddetecttheminutesteffectsofanydisturbance，eachparticleofexistingmattermustbearegisterofallthathashappened。Thetrackofeverycanoe，ofeveryvesselthathasyetdisturbedthesurfaceoftheocean，whetherimpelledbymanualforceorelementalpower，remainsforeverregisteredinthefuturemovementofallsucceedingparticleswhichmayoccupyitsplace。Thefurrowwhichisleftis，indeed，instantlyfilledupbytheclosingwaters；
buttheydrawafterthemotherandlargerportionsofthesurroundingelement，andtheseagain，oncemoved，communicatemotiontoothersinendlesssuccession。“Inlikemanner，“theairitselfisonevastlibrary，onwhosepagesareforeverwrittenallthatmanhaseversaidorevenwhispered。Thereintheirmutablebutunerringcharacters，mixedwiththeearliestaswellasthelatestsighsofmortality，standforeverrecordedvowsunredeemed，promisesunfulfilled，perpetuatingintheunitedmovementsofeachparticlethetestimonyofman’schangefulwill。“[6]Insomesuchwayasthis，recordsofeverymovementthattakesplaceintheworldareeachmomenttransmitted，withthespeedoflight，throughtheinvisibleoceanofetherwithwhichtheworldissurrounded。Eventhemoleculardisplacementswhichoccurinourbrainswhenwefeelandthinkarethuspropagatedintheireffectsintotheunseenworld。Theworldofetheristhusregardedbyourauthorsasinsomesorttheobverseorcomplementoftheworldofsensiblematter，sothatwhateverenergyisdissipatedintheoneisbythesameactaccumulatedintheother。Itislikethenegativeplateinphotography，wherelightanswerstoshadowandshadowtolight。Or，stillbetter，itislikethecaseofanequationinwhichwhateverquantityyoutakefromonesideisaddedtotheotherwithacontrarysign，whiletherelationofequalityremainsundisturbed。Thus，itwillbenoticed，fromtheingeniousandsubtle，butquitedefensiblesuggestionofMr。Babbage，aleapismadetoanassumptionwhichcannotbedefendedscientifically，butonlyteleologically。Itisonethingtosaythateverymovementinthevisibleworldtransmitsarecordofitselftothesurroundingether，insuchawaythatfromtheundulationoftheetherasufficientlypowerfulintelligencemightinferthecharacterofthegeneratingmovementinthevisibleworld。Itisquiteanotherthingtosaythattheetherisorganizedinsuchacomplexanddelicatewayastobelikeanegativeimageorcounterpartoftheworldofsensiblematter。Thelatterviewisnodoubtingenious，butitisgratuitous。Itissustainednotbyscientificanalogy，butbythedesiretofindsomeassignableusefortheenergywhichisconstantlyescapingfromvisiblematterintoinvisibleether。Themomentweaskhowdoweknowthatthisenergyisnotreallywasted，orthatitisnotputtosomeusewhollyundiscoverablebyhumanintelligence，thisassumptionofanorganizedetherisatonceseentobegroundless。Itbelongsnottotheregionofscience，buttothatofpuremythology。
[6]Babbage，NinthBridgewaterTreatise，p。115；Jevons，PrinciplesofScience，Vol。II。p。455。
Injusticetoourauthors，however，itshouldberememberedthatthisassumptionisputforthnotassomethingscientificallyprobable，butassomethingwhichforaughtweknowtothecontrarymaypossiblybetrue。This，tobesure，weneednotdeny；norifweonceallowthisprodigiousleapofinference，shallwefindmuchdifficultyinreachingthefamousconclusionthat“thoughtconceivedtoaffectthematterofanotheruniversesimultaneouslywiththismayexplainafuturestate。“Thisproposition，quaintlycouchedinananagram，likethediscoveriesofoldastronomers，waspublishedlastyearin“Nature，“ascontainingthegistoftheforthcomingbook。Onthenegative-imagehypothesisitisnothardtoseehowthoughtisconceivedtoaffecttheseenandtheunseenworldssimultaneously。Everyactofconsciousnessisaccompaniedbymoleculardisplacementsinthebrain，andtheseareofcourserespondedtobymovementsintheetherealworld。Thusasaseriesofconsciousstatesbuildupacontinuousmemoryinstrictaccordancewithphysicallawsofmotion，[7]soacorrelativememoryissimultaneouslybuiltupintheetherealworldoutoftheetherealcorrelativesofthemoleculardisplacementswhichgooninourbrains。Andasthereisacontinualtransferofenergyfromthevisibleworldtotheether，theextinctionofvitalenergywhichwecalldeathmustcoincideinsomewaywiththeawakeningofvitalenergyinthecorrelativeworld；sothatthedarkeningofconsciousnesshereiscoincidentwithitsdawningthere。Inthiswaydeathisfortheindividualbutatransferfromonephysicalstateofexistencetoanother；andso，onthelargestscale，thedeathorfinallossofenergybythewholevisibleuniversehasitscounterpartintheacquirementofamaximumoflifebythecorrelativeunseenworld。
Thereseemstobeacertainsortofrigorouslogicalconsistencyinthisdaringspeculation；butreallythepropositionsofwhichitconsistsaresofarfromansweringtoanythingwithinthedomainofhumanexperiencethatweareunabletotellwhetheranyoneofthemlogicallyfollowsfromitspredecessorornot。Itisevidentthatwearequiteoutoftheregionofscientifictests，andtowhateverviewourauthorsmayurgewecanonlylanguidlyassentthatitisoutofourpowertodisproveit。
[7]SeemyOutlinesofCosmicPhilosophy，Vol。II。pp。142-148。
Theessentialweaknessofsuchatheoryasthisliesinthefactthatitisthoroughlymaterialisticincharacter。Itiscurrentlyassumedthatthedoctrineofalifeafterdeathcannotbedefendedonmaterialisticgrounds，butthisisaltogethertoohastyanassumption。Ourauthors，indeed，arenotphilosophicalmaterialists，likeDr。Priestley，——whoneverthelessbelievedinafuturelife，——butoneoftheprimarydoctrinesofmaterialismliesatthebottomoftheirargument。Materialismholdsforonethingthatconsciousnessisaproductofapeculiarorganizationofmatter，andforanotherthingthatconsciousnesscannotsurvivethedisorganizationofthematerialbodywithwhichitisassociated。Asheldbyphilosophicalmaterialists，likeBuchnerandMoleschott，thesetwoopinionsarestrictlyconsistentwitheachother；nay，thelatterseemstobetheinevitableinferencefromtheformer，thoughPriestleydidnotsoregardit。