Thevastsignificanceofthisview，anditspowerinresistinganyrealastronomicalscience，weshallsee，especiallyinthetimeofGalileo。
　　ThegreattriadofthinkersculminatedinSt。ThomasAquinas——thesaintedtheologian，thegloryofthemediaevalChurch，the“AngelicDoctor。”themostmarvellousintellectbetweenAristotleandNewton；hetowhomitwasbelievedthatanimageoftheCrucifiedhadspokenwordspraisinghiswritings。
　　Largeofmind，strong，acute，yetjust——evenmorethanjust——tohisopponents，hegaveforth，inthelatterhalfofthethirteenthcentury，hisCyclopaediaofTheology，theSummaTheologica。Inthishecarriedthesacredtheoryoftheuniversetoitsfulldevelopment。Withgreatpowerandclearnesshebroughtthewholevastsystem，materialandspiritual，intoitsrelationstoGodandman。[42]
　　[42]ForthebeliefsofChaldeanastronomersinrevolvingspherescarryingsun，moon，andplanets，inasolidfirmamentsupportingthecelestialwaters，andinangelsasgivingmotiontotheplanets，seeLenormant；alsoLethaby，13-21；alsoSchroeder，Jensen，Lukas，etal。Forthecontributionofthepseudo-
　　Dionysiustomediaevalcosmology，seeDion。Areopagita，DeCoelestiHierarchia，vers。Joan。Scoti，inMigne，Patr。Lat。，cxxii。ForthecontributionofPeterLombard，seePet。Lomb。，Libr。Sent。，II，i，8，-IV，i，6，7，inMigne，tome192。ForthecitationsfromSt。ThomasAquinas，seetheSumma，ed。Migne，especiallyParsI，Qu。70，tomei，pp。1174-1184；alsoQuaestio47，Art。iii。Forgoodgeneralstatement，seeMilman，LatinChristianity，iv，191etseq。；andforrelationofCosmastothesetheologiansofwesternEurope，seeMilman，asabove，viii，228，note。
　　Thuswasthevastsystemdevelopedbythesethreeleadersofmediaevalthought；andnowcamethemanwhowroughtityetmoredeeplyintoEuropeanbelief，thepoetdivinelyinspiredwhomadethesystempartoftheworld’sLIFE。PicturedbyDante，theempyreanandtheconcentricheavens，paradise，purgatory，andhell，wereseenofallmen；theGodTriune，seatedonhisthroneuponthecircleoftheheavens，asrealasthePopeseatedinthechairofSt。Peter；theseraphim，cherubim，andthrones，surroundingtheAlmighty，asrealasthecardinalssurroundingthePope；thethreegreatordersofangelsinheaven，asrealasthethreegreatorders，bishops，priests，anddeacons，onearth；
　　andthewholesystemofspheres，eachrevolvingwithintheoneaboveit，andallmovingabouttheearth，subjecttotheprimummobile，asrealasthefeudalsystemofwesternEurope，subjecttotheEmperor。[43]
　　[43]Forthecentralsun，hierarchyofangels，andconcentriccircles，seeDante，Paradiso，cantoxxviii。ForthewordsofSt。
　　ThomasAquinas，showingtoVirgilandDantethegreattheologiansoftheMiddleAges，seecantox，andinDeanPlumptre’stranslation，vol。ii，pp。56etseq。；alsoBotta，Dante，pp。350，351。AstoDante’sdeepreligiousfeelingandbeliefinhisowndivinemission，seeJ。R。Lowell，AmongmyBooks，vol。i，p。36。
　　Foraremarkableseriesofcolouredengravings，showingDante’swholecosmology，seeLaMateriadellaDivinaComediadiDantedichiriatainvitavole，daMichelangeloCaetani，publishedbythemonksofMonteCassino，towhosekindnessIamindebtedformycopy。
　　Letuslookintothisvastcreation——thehighestachievementoftheology——somewhatmoreclosely。
　　Itsfirstfeatureshowsadevelopmentoutofearliertheologicalideas。Theearthisnolongeraflatplaininclosedbyfourwallsandsolidlyvaultedabove，astheologiansofpreviouscenturieshadbelievedit，undertheinspirationofCosmas；itisnolongeramereflatdisk，withsun，moon，andstarshunguptogiveitlight，astheearliercathedralsculptorshadfiguredit；
　　ithasbecomeaglobeatthecentreoftheuniverse。
　　Encompassingitaresuccessivetransparentspheres，rotatedbyangelsabouttheearth，andeachcarryingoneormoreoftheheavenlybodieswithit：thatnearesttheearthcarryingthemoon；thenext，Mercury；thenext，Venus；thenext，theSun；thenextthree，Mars，Jupiter，andSaturn；theeighthcarryingthefixedstars。Theninthwastheprimummobile，andinclosingallwasthetenthheaven——theEmpyrean。Thiswasimmovable——theboundarybetweencreationandthegreatoutervoid；andhere，inalightwhichnoonecanenter，theTriuneGodsatenthroned，the“musicofthespheres“risingtoHimastheymoved。ThuswastheoldheathendoctrineofthespheresmadeChristian。
　　InattendanceupontheDivineMajesty，thusenthroned，arevasthostsofangels，whoaredividedintothreehierarchies，oneservingintheempyrean，oneintheheavens，betweentheempyreanandtheearth，andoneontheearth。
　　Eachofthesehierarchiesisdividedintothreechoirs，ororders；thefirst，intotheordersofSeraphim，Cherubim，andThrones；andthemainoccupationoftheseistochantincessantly——to“continuallycry“thedivinepraises。
　　TheorderofThronesconveysGod’swilltothesecondhierarchy，whichservesinthemovableheavens。Thissecondhierarchyisalsomadeupofthreeorders。Thefirstofthese，theorderofDominions，receivesthedivinecommands；thesecond，theorderofPowers，movestheheavens，sun，moon，planets，andstars，opensandshutsthe“windowsofheaven。”andbringstopassallothercelestialphenomena；thethird，theorderofEmpire，guardstheothers。
　　Thethirdandlowesthierarchyisalsomadeupofthreeorders。
　　FirstofthesearethePrincipalities，theguardianspiritsofnationsandkingdoms。NextcomeArchangels；theseprotectreligion，andbeartheprayersofthesaintstothefootofGod’sthrone。FinallycomeAngels；thesecareforearthlyaffairsingeneral，onebeingappointedtoeachmortal，andotherstakingchargeofthequalitiesofplants，metals，stones，andthelike。
　　Throughoutthewholesystem，fromthegreatTriuneGodtothelowestgroupofangels，weseeatworkthemysticpowerattachedtothetriangleandsacrednumberthree——thesamewhichgavethetriuneideatoancientHindutheology，whichdevelopedthetriunedeitiesinEgypt，andwhichtransmittedthistheologicalgifttotheChristianworld，especiallythroughtheEgyptianAthanasius。
　　Belowtheearthishell。ThisistenantedbytheangelswhorebelledundertheleadofLucifer，princeoftheseraphim——theformerfavouriteoftheTrinity；but，oftheserebelliousangels，somestillroveamongtheplanetaryspheres，andgivetroubletothegoodangels；otherspervadetheatmosphereabouttheearth，carryinglightning，storm，drought，andhail；othersinfestearthlysociety，temptingmentosin；butPeterLombardandSt。ThomasAquinastakepainstoshowthattheworkofthesedevilsis，afterall，buttodisciplinemanortometeoutdeservedpunishment。
　　AllthisvastschemehadbeensorivetedintothePtolemaicviewbytheuseofbiblicaltextsandtheologicalreasoningsthattheresultantsystemoftheuniversewasconsideredimpregnableandfinal。Toattackitwasblasphemy。
　　Itstoodforcenturies。Greattheologicalmenofscience，likeVincentofBeauvaisandCardinald’Ailly，devotedthemselvestoshowingnotonlythatitwassupportedbyScripture，butthatitsupportedScripture。Thuswasthegeocentrictheoryembeddedinthebeliefsandaspirations，inthehopesandfears，ofChristendomdowntothemiddleofthesixteenthcentury。[44]
　　[44]FortheearliercosmologyofCosmas，withcitationsfromMontfaucon，seethechapteronGeographyinthiswork。Fortheviewsofmediaevaltheologians，seeforegoingnotesinthischapter。ForthepassagesofScriptureonwhichthetheologicalpartofthisstructurewasdeveloped，seeespeciallyRomansviii，38；Ephesiansi，21；Colossiansi，16aandii，15；andinnumerablepassagesintheOldTestament。Astothemusicofthespheres，seeDeanPlumptre’sDante，vol。ii，p。4，note。Foranadmirablesummingupofthemediaevalcosmologyinitsrelationtothoughtingeneral，seeRydberg，MagicoftheMiddleAges，chap。i，whosesummaryIhavefollowedinthemain。Forstrikingwoodcutsshowingtheviewtakenofthesuccessiveheavenswiththeirchoirsofangels，theearthbeingatthecentrewiththespheresaboutit，andtheAlmightyonhisthroneaboveall，seetheNeurembergChronicle，ff。ivandv；itsdateis1493。Forchartsshowingthecontinuanceofthisgeneralviewdowntothebeginningofthesixteenthcentury，seethevariouseditionsoftheMargaritaPhilosophica，fromthatof1503onward，astronomicalpart。ForinterestingstatementsregardingtheTrinitiesofgodsinancientEgypt，seeSharpe，HistoryofEgypt，vol。i，pp。94and101。ThepresentwriteronceheardalectureinCairo，fromaneminentScotchDoctorofMedicine，toaccountfortheancientHinduandEgyptiansacredthreesandtrinities。
　　Thelecturer’stheorywasthat，whenJehovahcamedownintotheGardenofEdenandwalkedwithAdamin“thecooloftheday。”heexplainedhistriunecharactertoAdam，andthatfromAdamitwasspreadabroadtothevariousancientnations。
　　II。THEHELIOCENTRICTHEORY。
　　But，ontheotherhand，therehadbeenplanted，longbefore，thegermsofaheliocentrictheory。Inthesixthcenturybeforeourera，Pythagoras，andafterhimPhilolaus，hadsuggestedthemovementoftheearthandplanetsaboutacentralfire；and，threecenturieslater，Aristarchushadrestatedthemaintruthwithstrikingprecision。HerecomesinaproofthattheantagonismbetweentheologicalandscientificmethodsisnotconfinedtoChristianity；forthisstatementbroughtuponAristarchusthechargeofblasphemy，anddrewafteritacloudofprejudicewhichhidthetruthforsixhundredyears。NotuntilthefifthcenturyofoureradidittimidlyappearinthethoughtsofMartianusCapella：thenitwasagainlosttosightforathousandyears，untilinthefifteenthcentury，distortedandimperfect，itappearedinthewritingsofCardinalNicholasdeCusa。
　　Butintheshadecastbythevastsystemwhichhadgrownfromthemindsofthegreattheologiansandfromtheheartofthegreatpoettherehadcometothistruthneitherbloomnorfruitage。
　　Quietly，however，thesoilwasreceivingenrichmentandtheairwarmth。Theprocessesofmathematicswereconstantlyimproved，theheavenlybodiesweresteadilyobserved，andatlengthappeared，farfromthecentresofthought，onthebordersofPoland，aplain，simple-mindedscholar，whofirstfairlyutteredtothemodernworldthetruth——nowsocommonplace，thensoastounding——thatthesunandplanetsdonotrevolveabouttheearth，butthattheearthandplanetsrevolveaboutthesun：
　　thismanwasNicholasCopernicus。
　　CopernicushadbeenaprofessoratRome，andevenasearlyas1500hadannouncedhisdoctrinethere，butmoreinthewayofascientificcuriosityorparadox，asithadbeenpreviouslyheldbyCardinaldeCusa，thanasthestatementofasystemrepresentingagreatfactinNature。Aboutthirtyyearslateroneofhisdisciples，Widmanstadt，hadexplainedittoClementVII；butitstillremainedamerehypothesis，andsoon，likesomanyothers，disappearedfromthepublicview。ButtoCopernicus，steadilystudyingthesubject，itbecamemoreandmoreareality，andasthistruthgrewwithinhimheseemedtofeelthatatRomehewasnolongersafe。Toannouncehisdiscoverythereasatheoryoraparadoxmightamusethepapalcourt，buttoannounceitasatruth——asTHEtruth——wasafardifferentmatter。HethereforereturnedtohislittletowninPoland。
　　Topublishhisthoughtasithadnowdevelopedwasevidentlydangerouseventhere，andformorethanthirtyyearsitlayslumberinginthemindofCopernicusandofthefriendstowhomhehadprivatelyintrustedit。
　　AtlasthepreparedhisgreatworkontheRevolutionsoftheHeavenlyBodies，anddedicatedittothePopehimself。Henextsoughtaplaceofpublication。HedarednotsendittoRome，forthereweretherulersoftheolderChurchreadytoseizeit；hedarednotsendittoWittenberg，forthereweretheleadersofProtestantismnolesshostile；hethereforeintrustedittoOsiander，atNuremberg。[45]
　　[45]Forthegermsofheliocentrictheoryplantedlongbefore，seeSirG。C。Lewis；andforasuccinctstatementoftheclaimsofPythagoras，Philolaus，Aristarchus，andMartianusCapella，seeHoefer，Hisoiredel’Astronomie，1873，p。107etseq。；alsoHeller，GeschichtederPhysik，Stuttgart，1882，vol。i，pp。12，13；alsopp。99etseq。ForgermsamongthinkersofIndia，seeWhewell，vol。i，p。277；alsoWhitney，OrientalandLinguisticStudies，NewYork，1874；EssayontheLunarZodiac，p。345。FortheviewsofVincentofBeauvais，seehisSpeculumNaturale，lib。
　　xvi，cap。21。ForCardinald’Ailly’sview，seehistreatiseDeConcordiaAstronomicaeVeritatiscumTheologiainhisYmagoMundiandseparately。ForgeneralstatementofDeCusa’swork，seeDraper，IntellectualDevelopmentofEurope，p。512。ForskilfuluseofDeCusa’sviewinordertomitigatecensureupontheChurchforitstreatmentofCopernicus’sdiscovery，seeanarticleintheCatholicWorldforJanuary，1869。Foraveryexactstatement，inthespiritofjudicialfairness，seeWhewell，HistoryoftheInductiveSciences，p。275，andpp。379，380。Inthelatter，WhewellcitestheexactwordsofDeCusaintheDeDoctaIgnorantia，andsumsupinthesewords：“ThistrainofthoughtmightbeapreparationforthereceptionoftheCopernicansystem；butitisverydifferentfromthedoctrinethatthesunisthecentreoftheplanetarysystem。”Whewellsays：“DeCusapropoundedthedoctrineofthemotionoftheearthmoreasaparadoxthanasareality。Wecannotconsiderthisasanydistinctanticipationofaprofoundandconsistentviewofthetruth。”OnDeCusa，seealsoHeller，vol。i，p。216。ForAristotle’sviews，andtheirelaborationbySt。ThomasAquinas，seetheDeCoeloetMundo，sec。xx，andelsewhereinthelatter。