Shouldthestorythatisabouttobeunfoldedbefoundtolackinterest，thewritersmuststandconvictedofunpardonablelackofart。Nothingbutdulnessinthetellingcouldmarthestory，forinitselfitistherecordofthegrowthofthoseideasthathavemadeourraceanditscivilizationwhattheyare；ofideasinstinctwithhumaninterest，vitalwithmeaningforourrace；
　　fundamentalintheirinfluenceonhumandevelopment；partandparcelofthemechanismofhumanthoughtontheonehand，andofpracticalcivilizationontheother。Suchaphraseas"fundamentalprinciples"mayseematfirstthoughtahardsaying，buttheideaitimpliesislessrepellentthanthephraseitself，forthefundamentalprinciplesinquestionaresocloselylinkedwiththepresentinterestsofeveryoneofusthattheyliewithinthegraspofeveryaveragemanandwoman——nay，ofeverywell-developedboyandgirl。Theseprinciplesarenotmerelythestepping-stonestoculture，theprerequisitesofknowledge——theyare，inthemselves，anessentialpartoftheknowledgeofeverycultivatedperson。
　　Itisourtask，notmerelytoshowwhattheseprinciplesare，buttopointouthowtheyhavebeendiscoveredbyourpredecessors。
　　Weshalltracethegrowthoftheseideasfromtheirfirstvaguebeginnings。Weshallseehowvaguenessofthoughtgavewaytoprecision；howageneraltruth，oncegraspedandformulated，wasfoundtobeastepping-stonetoothertruths。Weshallseethattherearenoisolatedfacts，noisolatedprinciples，innature；
　　thateachpartofourstoryislinkedbyindissolublebandswiththatwhichgoesbefore，andwiththatwhichcomesafter。Forthemostpartthediscoveryofthisprincipleorthatinagivensequenceisnoaccident。GalileoandKepplermustprecedeNewton。
　　CuvierandLyallmustcomebeforeDarwin；——Which，afterall，isnomorethansayingthatinourTempleofScience，asinanyotherpieceofarchitecture，thefoundationmustprecedethesuperstructure。
　　Weshallbestunderstandourstoryofthegrowthofscienceifwethinkofeachnewprincipleasastepping-stonewhichmustfitintoitsownparticularniche；andifwereflectthattheentirestructureofmoderncivilizationwouldbedifferentfromwhatitis，andlessperfectthanitis，hadnotthatparticularstepping-stonebeenfoundandshapedandplacedinposition。
　　Takenasawhole，ourstepping-stonesleadusupanduptowardsthealluringheightsofanacropolisofknowledge，onwhichstandstheTempleofModernScience。Thestoryofthebuildingofthiswonderfulstructureisinitselffascinatingandbeautiful。
　　I。PREHISTORICSCIENCE
　　Tospeakofaprehistoricsciencemayseemlikeacontradictionofterms。Thewordprehistoricseemstoimplybarbarism，whilescience，clearlyenough，seemstheoutgrowthofcivilization；butrightlyconsidered，thereisnocontradiction。For，ontheonehand，manhadceasedtobeabarbarianlongbeforethebeginningofwhatwecallthehistoricalperiod；and，ontheotherhand，science，ofakind，isnolessaprecursorandacauseofcivilizationthanitisaconsequent。Togetthisclearlyinmind，wemustaskourselves:What，then，isscience？Thewordrunsgliblyenoughuponthetongueofourevery-dayspeech，butitisnotoften，perhaps，thattheywhouseithabituallyaskthemselvesjustwhatitmeans。Yettheanswerisnotdifficult。A
　　littleattentionwillshowthatscience，asthewordiscommonlyused，impliesthesethings:first，thegatheringofknowledgethroughobservation；second，theclassificationofsuchknowledge，andthroughthisclassification，theelaborationofgeneralideasorprinciples。InthefamiliardefinitionofHerbertSpencer，scienceisorganizedknowledge。
　　Nowitispatentenough，atfirstglance，thattheveriestsavagemusthavebeenanobserverofthephenomenaofnature。Butitmaynotbesoobviousthathemustalsohavebeenaclassifierofhisobservations——anorganizerofknowledge。Yetthemoreweconsiderthecase，themoreclearitwillbecomethatthetwomethodsaretoocloselylinkedtogethertobedissevered。Toobserveoutsidephenomenaisnotmoreinherentinthenatureofthemindthantodrawinferencesfromthesephenomena。Adeerpassingthroughtheforestscentsthegroundanddetectsacertainodor。Asequenceofideasisgeneratedinthemindofthedeer。Nothinginthedeer’sexperiencecanproducethatodorbutawolf；thereforethescientificinferenceisdrawnthatwolveshavepassedthatway。
　　Butitisapartofthedeer’sscientificknowledge，basedonpreviousexperience，individualandracial；thatwolvesaredangerousbeasts，andso，combiningdirectobservationinthepresentwiththeapplicationofageneralprinciplebasedonpastexperience，thedeerreachestheverylogicalconclusionthatitmaywiselyturnaboutandruninanotherdirection。Allthisimplies，essentially，acomprehensionanduseofscientificprinciples；and，strangeasitseemstospeakofadeeraspossessingscientificknowledge，yetthereisreallynoabsurdityinthestatement。Thedeerdoespossessscientificknowledge；
　　knowledgedifferingindegreeonly，notinkind，fromtheknowledgeofaNewton。Noristheanimal，withintherangeofitsintelligence，lesslogical，lessscientificintheapplicationofthatknowledge，thanistheman。Theanimalthatcouldnotmakeaccuratescientificobservationsofitssurroundings，anddeduceaccuratescientificconclusionsfromthem，wouldsoonpaythepenaltyofitslackoflogic。
　　Whatistrueofman’sprecursorsintheanimalscaleis，ofcourse，trueinawiderandfullersenseofmanhimselfattheveryloweststageofhisdevelopment。Agesbeforethetimewhichthelimitationsofourknowledgeforceustospeakofasthedawnofhistory，manhadreachedahighstageofdevelopment。Asasocialbeing，hehaddevelopedalltheelementsofaprimitivecivilization。If，forconvenienceofclassification，wespeakofhisstateassavage，orbarbaric，weusetermswhich，afterall，arerelative，andwhichdonotshutoffourprimitiveancestorsfromatolerablycloseassociationwithourownideals。Weknowthat，evenintheStoneAge，manhadlearnedhowtodomesticateanimalsandmakethemusefultohim，andthathehadalsolearnedtocultivatethesoil。Lateron，doubtlessbyslowandpainfulstages，heattainedthosewonderfulelementsofknowledgethatenabledhimtosmeltmetalsandtoproduceimplementsofbronze，andthenofiron。EvenintheStoneAgehewasamechanicofmarvellousskill，asanyoneofto-daymaysatisfyhimselfbyattemptingtoduplicatesuchanimplementasachippedarrow-head。Andabarbarianwhocouldfashionanaxeoraknifeofbronzehadcertainlygonefarinhisknowledgeofscientificprinciplesandtheirpracticalapplication。Thepracticalapplicationwas，doubtless，theonlythoughtthatourprimitiveancestorhadinmind；quiteprobablythequestionastoprinciplesthatmightbeinvolvedtroubledhimnotatall。Yet，inspiteofhimself，heknewcertainrudimentaryprinciplesofscience，eventhoughhedidnotformulatethem。
　　Letusinquirewhatsomeoftheseprinciplesare。Suchaninquirywill，asitwere，clearthegroundforourstructureofscience。
　　Itwillshowtheplaneofknowledgeonwhichhistoricalinvestigationbegins。Incidentally，perhaps，itwillrevealtousunsuspectedaffinitiesbetweenourselvesandourremoteancestor。
　　Withoutattemptinganythinglikeafullanalysis，wemaynoteinpassing，notmerelywhatprimitivemanknew，butwhathedidnotknow；thatatleastavaguenotionmaybegainedofthefieldforscientificresearchthatlayopenforhistoricmantocultivate。
　　Itmustbeunderstoodthattheknowledgeofprimitiveman，asweareabouttooutlineit，isinferential。Wecannottracethedevelopmentoftheseprinciples，muchlesscanwesaywhodiscoveredthem。Someofthem，asalreadysuggested，areman’sheritagefromnon-humanancestors。Otherscanonlyhavebeengraspedbyhimafterhehadreachedarelativelyhighstageofhumandevelopment。Butalltheprinciplesherelistedmustsurelyhavebeenpartsofourprimitiveancestor’sknowledgebeforethoseearliestdaysofEgyptianandBabyloniancivilization，therecordsofwhichconstituteourfirstintroductiontotheso-calledhistoricalperiod。Takensomewhatintheorderoftheirprobablediscovery，thescientificideasofprimitivemanmayberoughlylistedasfollows:
　　1。Primitivemanmusthaveconceivedthattheearthisflatandoflimitlessextent。Bythisitisnotmeanttoimplythathehadadistinctconceptionofinfinity，but，forthatmatter，itcannotbesaidthatanyoneto-dayhasaconceptionofinfinitythatcouldbecalleddefinite。But，reasoningfromexperienceandthereportsoftravellers，therewasnothingtosuggesttoearlymanthelimitoftheearth。Hedid，indeed，findinhiswanderings，thatchangedclimaticconditionsbarredhimfromfartherprogress；butbeyondthefarthestreachesofhismigrations，theseeminglyflatland-surfacesandwater-surfacesstretchedawayunbrokenand，toallappearances，withoutend。Itwouldrequireareachofthephilosophicalimaginationtoconceivealimittotheearth，andwhilesuchimaginingsmayhavebeencurrentintheprehistoricperiod，wecanhavenoproofofthem，andwemaywellpostponeconsiderationofman’searlydreamingsastotheshapeoftheearthuntilweenterthehistoricalepochwherewestandonfirmground。
　　2。Primitivemanmust，fromaveryearlyperiod，haveobservedthatthesungivesheatandlight，andthatthemoonandstarsseemtogivelightonlyandnoheat。Itrequiredbutaslightextensionofthisobservationtonotethatthechangingphasesoftheseasonswereassociatedwiththeseemingapproachandrecessionofthesun。Thisobservation，however，couldnothavebeenmadeuntilmanhadmigratedfromthetropicalregions，andhadreachedastageofmechanicaldevelopmentenablinghimtoliveinsubtropicalortemperatezones。Eventhenitisconceivablethatalongperiodmusthaveelapsedbeforeadirectcausalrelationwasfelttoexistbetweentheshiftingofthesunandtheshiftingoftheseasons；because，aseveryoneknows，theperiodsofgreatestheatinsummerandgreatestcoldinwinterusuallycomesomeweeksafterthetimeofthesolstices。Yet，thefactthattheseextremesoftemperatureareassociatedinsomewaywiththechangeofthesun’splaceintheheavensmust，intime，haveimpresseditselfuponevenarudimentaryintelligence。
　　Itishardlynecessarytoaddthatthisisnotmeanttoimplyanydefiniteknowledgeoftherealmeaningof，theseemingoscillationsofthesun。Weshallseethat，evenatarelativelylateperiod，thevaguestnotionswerestillinvogueastothecauseofthesun’schangesofposition。
　　Thatthesun，moon，andstarsmoveacrosstheheavensmustobviouslyhavebeenamongtheearliestscientificobservations。
　　Itmustnotbeinferred，however，thatthisobservationimpliedanecessaryconceptionofthecompleterevolutionofthesebodiesabouttheearth。Itisunnecessarytospeculatehereastohowtheprimitiveintelligenceconceivedthetransferofthesunfromthewesterntotheeasternhorizon，tobeeffectedeachnight，forweshallhaveoccasiontoexaminesomehistoricalspeculationsregardingthisphenomenon。Wemayassume，however，thattheideaofthetransferoftheheavenlybodiesbeneaththeearthwhatevertheconceptionastotheformofthatbodymustearlyhavepresenteditself。
　　Itrequiredarelativelyhighdevelopmentoftheobservingfaculties，yetadevelopmentwhichmanmusthaveattainedagesbeforethehistoricalperiod，tonotethatthemoonhasasecondarymotion，whichleadsittoshiftitsrelativepositionintheheavens，asregardsthestars；thatthestarsthemselves，ontheotherhand，keepafixedrelationasregardsoneanother，withthenotableexceptionoftwoorthreeofthemostbrilliantmembersofthegalaxy，thelatterbeingthebodieswhichcametobeknownfinallyasplanets，orwanderingstars。ThewanderingpropensitiesofsuchbrilliantbodiesasJupiterandVenuscannotwellhaveescapeddetection。Wemaysafelyassume，however，thattheseanomalousmotionsofthemoonandplanetsfoundnoexplanationthatcouldbecalledscientificuntilarelativelylateperiod。
　　3。Turningfromtheheavenstotheearth，andignoringsuchprimitiveobservationsasthatofthedistinctionbetweenlandandwater，wemaynotethattherewasonegreatscientificlawwhichmusthaveforceditselfupontheattentionofprimitiveman。Thisisthelawofuniversalterrestrialgravitation。ThewordgravitationsuggeststhenameofNewton，anditmayexcitesurprisetohearaknowledgeofgravitationascribedtomenwhoprecededthatphilosopherby，say，twenty-fiveorfiftythousandyears。Yettheslightestconsiderationofthefactswillmakeitclearthatthegreatcentrallawthatallheavybodiesfalldirectlytowardstheearth，cannothaveescapedtheattentionofthemostprimitiveintelligence。Thearborealhabitsofourprimitiveancestorsgaveopportunitiesforconstantobservationofthepracticalitiesofthislaw。And，sosoonasmanhaddevelopedthementalcapacitytoformulateideas，oneoftheearliestideasmusthavebeentheconception，howevervaguelyphrasedinwords，thatallunsupportedbodiesfalltowardstheearth。Thesamephenomenonbeingobservedtooperateonwater-surfaces，andnoalterationbeingobservedinitsoperationindifferentportionsofman’shabitat，themostprimitivewanderermusthavecometohavefullfaithintheuniversalactionoftheobservedlawofgravitation。Indeed，itisinconceivablethathecanhaveimaginedaplaceontheearthwherethislawdoesnotoperate。Ontheotherhand，ofcourse，henevergraspedtheconceptionoftheoperationofthislawbeyondthecloseproximityoftheearth。Toextendthereachofgravitationouttothemoonandtothestars，includingwithinitscompasseveryparticleofmatterintheuniverse，wastheworkofNewton，asweshallseeinduecourse。Meantimeweshallbetterunderstandthatworkifwerecallthatthemerelocalfactofterrestrialgravitationhasbeenthefamiliarknowledgeofallgenerationsofmen。ItmayfurtherhelptoconnectusinsympathywithourprimevalancestorifwerecallthatintheattempttoexplainthisfactofterrestrialgravitationNewtonmadenoadvance，andweofto-dayarescarcelymoreenlightenedthanthemanoftheStoneAge。LikethemanoftheStoneAge，weknowthatanarrowshotintotheskyfallsbacktotheearth。Wecancalculate，ashecouldnotdo，thearcitwilldescribeandtheexactspeedofitsfall；butastowhyitreturnstoearthatall，thegreatestphilosopherofto-dayisalmostasmuchinthedarkaswasthefirstprimitivebowmanthatevermadetheexperiment。
　　Otherphysicalfactsgoingtomakeupanelementaryscienceofmechanics，thatweredemonstrativelyknowntoprehistoricman，weresuchasthese:therigidityofsolidsandthemobilityofliquids；thefactthatchangesoftemperaturetransformsolidstoliquidsandviceversa——thatheat，forexample，meltscopperandeveniron，andthatcoldcongealswater；andthefactthatfriction，asillustratedintherubbingtogetheroftwosticks，mayproduceheatenoughtocauseafire。Therationaleofthislastexperimentdidnotreceiveanexplanationuntilaboutthebeginningofthenineteenthcenturyofourownera。Buttheexperimentalfactwassowellknowntoprehistoricmanthatheemployedthismethod，asvarioussavagetribesemployittothisday，forthealtogetherpracticalpurposeofmakingafire；justasheemployedhispracticalknowledgeofthemutabilityofsolidsandliquidsinsmeltingores，inalloyingcopperwithtintomakebronze，andincastingthisalloyinmoldstomakevariousimplementsandweapons。Here，then，werethegermsofanelementaryscienceofphysics。Meanwhilesuchobservationsasthatofthesolutionofsaltinwatermaybeconsideredasgivingafirstlessoninchemistry，butbeyondsuchaltogetherrudimentaryconceptionschemicalknowledgecouldnothavegone——unless，indeed，thepracticalobservationoftheeffectsoffirebeincluded；norcanthiswellbeoverlooked，sincescarcelyanothersinglelineofpracticalobservationhadamoredirectinfluenceinpromotingtheprogressofmantowardstheheightsofcivilization。
　　4。Inthefieldofwhatwenowspeakofasbiologicalknowledge，primitivemanhadobviouslythewidestopportunityforpracticalobservation。Wecanhardlydoubtthatmanattained，atanearlyday，tothatconceptionofidentityandofdifferencewhichPlatoplacesattheheadofhismetaphysicalsystem。Weshallurgepresentlythatitispreciselysuchgeneralideasasthesethatwereman’searliestinductionsfromobservation，andhencethatcametoseemthemostuniversaland"innate"ideasofhismentality。Itisquiteinconceivable，forexample，thateventhemostrudimentaryintelligencethatcouldbecalledhumancouldfailtodiscriminatebetweenlivingthingsand，letussay，therocksoftheearth。Themostprimitiveintelligence，then，musthavemadeatacitclassificationofthenaturalobjectsaboutitintothegranddivisionsofanimateandinanimatenature。
　　Doubtlessthenascentscientistmayhaveimaginedlifeanimatingmanybodiesthatweshouldcallinanimate——suchasthesun，wanderingplanets，thewinds，andlightning；and，ontheotherhand，hemayquitelikelyhaverelegatedsuchobjectsastreestotheranksofthenon-living；butthatherecognizedafundamentaldistinctionbetween，letussay，awolfandagranitebowlderwecannotwelldoubt。Astepbeyondthis——astep，however，thatmayhaverequiredcenturiesormillenniumsinthetaking——musthavecarriedmantoaplaneofintelligencefromwhichaprimitiveAristotleorLinnaeuswasenabledtonotedifferencesandresemblancesconnotingsuchgroupsofthingsasfishes，birds，andfurrybeasts。Thisconception，tobesure，isanabstractionofarelativelyhighorder。Weknowthattherearesavageracesto-daywhoselanguagecontainsnowordforsuchanabstractionasbirdortree。Weareboundtobelieve，then，thattherewerelongagesofhumanprogressduringwhichthehighestmanhadattainednosuchstageofabstraction；but，ontheotherhand，itisequallylittleinquestionthatthisdegreeofmentaldevelopmenthadbeenattainedlongbeforetheopeningofourhistoricalperiod。Theprimevalman，then，whosescientificknowledgeweareattemptingtopredicate，hadbecome，throughhisconceptionoffishes，birds，andhairyanimalsasseparateclasses，ascientificzoologistofrelativelyhighattainments。
　　Inthepracticalfieldofmedicalknowledge，acertainstageofdevelopmentmusthavebeenreachedataveryearlyday。Evenanimalspickandchooseamongthevegetablesaboutthem，andattimesseekoutcertainherbsquitedifferentfromtheirordinaryfood，practisingasortofinstinctivetherapeutics。Thecat’sfondnessforcatnipisacaseinpoint。Themostprimitiveman，then，musthaveinheritedaracialorinstinctiveknowledgeofthemedicinaleffectsofcertainherbs；inparticularhemusthavehadsuchelementaryknowledgeoftoxicologyaswouldenablehimtoavoideatingcertainpoisonousberries。Perhaps，indeed，weareplacingtheeffectbeforethecausetosomeextent；for，afterall，theanimalsystempossessesmarvellouspowersofadaption，andthereisperhapshardlyanypoisonousvegetablewhichmanmightnothavelearnedtoeatwithoutdeleteriouseffect，providedtheexperimentweremadegradually。Toacertainextent，then，theobservedpoisonouseffectsofnumerousplantsuponthehumansystemaretobeexplainedbythefactthatourancestorshaveavoidedthisparticularvegetable。Certainfruitsandberriesmighthavecometohavebeenapartofman’sdiet，hadtheygrownintheregionsheinhabitedatanearlyday，whichnowarepoisonoustohissystem。Thisthought，however，carriesustoofarafield。Forpracticalpurposes，itsufficesthatcertainroots，leaves，andfruitspossessprinciplesthatarepoisonoustothehumansystem，andthatunlessmanhadlearnedinsomewaytoavoidthese，ourracemusthavecometodisaster。Inpointoffact，hedidlearntoavoidthem；andsuchevidenceimplied，ashasbeensaid，anelementaryknowledgeoftoxicology。
　　Coupledwiththisknowledgeofthingsdangeroustothehumansystem，theremusthavegrownup，ataveryearlyday，abeliefintheremedialcharacterofvariousvegetablesasagentstocombatdisease。Here，ofcourse，wasarudimentarytherapeutics，acrudeprincipleofanempiricalartofmedicine。Asjustsuggested，thelowerorderofanimalshaveaninstinctiveknowledgethatenablesthemtoseekoutremedialherbsthoughweprobablyexaggeratetheextentofthisinstinctiveknowledge；
　　andifthisbetrue，manmusthaveinheritedfromhisprehumanancestorsthisinstinctalongwiththeothers。Thatheextendedthisknowledgethroughobservationandpractice，andcameearlytomakeextensiveuseofdrugsinthetreatmentofdisease，isplacedbeyondcavilthroughtheobservationofthevariousexistingbarbarictribes，nearlyallofwhompracticeelaboratesystemsoftherapeutics。Weshallhaveoccasiontoseethatevenwithinhistorictimestheparticulartherapeuticmeasuresemployedwereoftencrude，and，asweareaccustomedtosay，unscientific；buteventhecrudestofthemarereallybaseduponscientificprinciples，inasmuchastheirapplicationimpliesthedeductionofprinciplesofactionfrompreviousobservations。
　　Certaindrugsareappliedtoappeasecertainsymptomsofdiseasebecauseinthebeliefofthemedicine-mansuchdrugshaveprovedbeneficialinprevioussimilarcases。
　　Allthis，however，impliesanappreciationofthefactthatmanissubjectto"natural"diseases，andthatifthesediseasesarenotcombated，deathmayresult。Butitshouldbeunderstoodthattheearliestmanprobablyhadnosuchconceptionasthis。
　　Throughoutalltheagesofearlydevelopment，whatwecall"natural"diseaseand"natural"deathmeanttheonslaughtofatangibleenemy。Astudyofthisquestionleadsustosomeverycuriousinferences。Themorewelookintothematterthemorethethoughtforcesitselfhometousthattheideaofnaturaldeath，aswenowconceiveit，cametoprimitivemanasarelativelylatescientificinduction。Thisthoughtseemsalmoststartling，soaxiomatichastheconception"manismortal"cometoappear。Yetastudyoftheideasofexistingsavages，combinedwithourknowledgeofthepointofviewfromwhichhistoricalpeoplesregarddisease，makeitmoreprobablethattheprimitiveconceptionofhumanlifedidnotincludetheideaofnecessarydeath。WearetoldthattheAustraliansavagewhofallsfromatreeandbreakshisneckisnotregardedashavingmetanaturaldeath，butashavingbeenthevictimofthemagicalpracticesofthe"medicine-man"ofsomeneighboringtribe。Similarly，weshallfindthattheEgyptianandtheBabylonianoftheearlyhistoricalperiodconceivedillnessasbeingalmostinvariablytheresultofthemachinationsofanenemy。OneneedbutrecallthesuperstitiousobservancesoftheMiddleAges，andtheyetmorerecentbeliefinwitchcraft，torealizehowgenerallydiseasehasbeenpersonifiedasamaliciousagentinvokedbyanunfriendlymind。Indeed，thephraseologyofourpresent-dayspeechisstillreminiscentofthis；aswhen，forexample，wespeakofan"attackoffever，"andthelike。
　　When，followingoutthisidea，wepicturetoourselvestheconditionsunderwhichprimitivemanlived，itwillbeevidentatoncehowrelativelyinfrequentmusthavebeenhisobservationofwhatweusuallytermnaturaldeath。Hisworldwasaworldofstrife；helivedbythechase；hesawanimalskilloneanother；
　　hewitnessedthedeathofhisownfellowsatthehandsofenemies。Naturallyenough，then，whenamemberofhisfamilywas"struckdown"byinvisibleagents，heascribedthisdeathalsotoviolence，eventhoughtheoffensiveagentwasconcealed。
　　Moreover，havingverylittleideaofthelapseoftime——beingquiteunaccustomed，thatis，toreckoneventsfromanyfixedera——primitivemancannothavegainedatonceaclearconceptionofageasappliedtohisfellows。Untilarelativelylatestageofdevelopmentmadetriballifepossible，itcannothavebeenusualformantohaveknowledgeofhisgrandparents；asarulehedidnotknowhisownparentsafterhehadpassedtheadolescentstageandhadbeenturnedoutupontheworldtocareforhimself。
　　If，then，certainofhisfellow-beingsshowedthoseevidencesofinfirmitywhichweascribetoage，itdidnotnecessarilyfollowthathesawanyassociationbetweensuchinfirmitiesandthelengthoftimewhichthosepersonshadlived。Theveryfactthatsomebarbaricnationsretainthecustomofkillingtheagedandinfirm，initselfsuggeststhepossibilitythatthiscustomarosebeforeaclearconceptionhadbeenattainedthatsuchdragsuponthecommunitywouldberemovedpresentlyinthenaturalorderofthings。Toapersonwhohadnoclearconceptionofthelapseoftimeandnopreconceptionastothelimitedperiodofman’slife，theinfirmitiesofagemightverynaturallybeascribedtotherepeatedattacksofthoseinimicalpowerswhichwereunderstoodsoonerorlatertocarryoffmostmembersoftherace。Andcoupledwiththisthoughtwouldgotheconceptionthatinasmuchassomepeoplethroughluckhadescapedthevengeanceofalltheirenemiesforlongperiods，thesesameindividualsmightcontinuetoescapeforindefiniteperiodsofthefuture。Therewerenowrittenrecordstotellprimevalmanofeventsoflongago。Helivedinthepresent，andhissweepofideasscarcelycarriedhimbackbeyondthelimitsofhisindividualmemory。Butmemoryisobservedtobefallacious。Itmustearlyhavebeennotedthatsomepeoplerecalledeventswhichotherparticipantsinthemhadquiteforgotten，anditmayreadilyenoughhavebeeninferredthatthosemembersofthetribewhospokeofeventswhichotherscouldnotrecallweremerelytheoneswhoweregiftedwiththebestmemories。Ifthesereachedaperiodwhentheirmemoriesbecamevague，itdidnotfollowthattheirrecollectionshadcarriedthembacktothebeginningsoftheirlives。Indeed，itiscontrarytoallexperiencetobelievethatanymanremembersallthethingshehasonceknown，andtheobservedfallaciousnessandevanescenceofmemorywouldthustendtosubstantiateratherthantocontroverttheideathatvariousmembersofatribehadbeenaliveforanindefiniteperiod。
　　Withoutfurtherelaboratingtheargument，itseemsajustifiableinferencethatthefirstconceptionprimitivemanwouldhaveofhisownlifewouldnotincludethethoughtofnaturaldeath，butwould，conversely，connotethevagueconceptionofendlesslife。
　　Ourownancestors，afewgenerationsremoved，hadnotgotridofthisconception，astheperpetualquestofthespringofeternalyouthamplytestifies。Anaturalistofourowndayhassuggestedthatperhapsbirdsneverdieexceptbyviolence。Thethought，then，thatmanhasatermofyearsbeyondwhich"inthenatureofthings，"asthesayinggoes，hemaynotlive，wouldhavedawnedbutgraduallyuponthedevelopingintelligenceofsuccessivegenerationsofmen；andwecannotfeelsurethathewouldfullyhavegraspedtheconceptionofa"natural"terminationofhumanlifeuntilhehadshakenhimselffreefromtheideathatdiseaseisalwaystheresultofthemagicpracticeofanenemy。Ourobservationofhistoricalmaninantiquitymakesitsomewhatdoubtfulwhetherthisconceptionhadbeenattainedbeforethecloseoftheprehistoricperiod。Ifithad，thisconceptionofthemortalityofmanwasoneofthemoststrikingscientificinductionstowhichprehistoricmanattained。Incidentally，itmaybenotedthattheconceptionofeternallifeforthehumanbodybeingamoreprimitiveideathantheconceptionofnaturaldeath，theideaoftheimmortalityofthespiritwouldbethemostnaturalofconceptions。Theimmortalspirit，indeed，wouldbebutacorrelativeoftheimmortalbody，andtheideawhichweshallseeprevalentamongtheEgyptiansthatthesoulpersistsonlyaslongasthebodyisintact——theideauponwhichthepracticeofmummifyingthedeaddepended——findsareadyexplanation。Butthisphaseofthesubjectcarriesussomewhatafield。Forourpresentpurposeitsufficestohavepointedoutthattheconceptionofman’smortality——aconceptionwhichnowseemsofallothersthemostnaturaland"innate"——wasinallprobabilityarelativelylatescientificinductionofourprimitiveancestors。
　　5。Turningfromtheconsiderationofthebodytoitsmentalcomplement，weareforcedtoadmitthathere，also，ourprimitivemanmusthavemadecertainelementaryobservationsthatunderliesuchsciencesaspsychology，mathematics，andpoliticaleconomy。
　　Theelementaryemotionsassociatedwithhungerandwithsatiety，withloveandwithhatred，musthaveforcedthemselvesupontheearliestintelligencethatreachedtheplaneofconsciousself-observation。Thecapacitytocount，atleasttothenumberfourorfive，iswithintherangeofevenanimalintelligence。
　　Certainsavageshavegonescarcelyfartherthanthis；butourprimevalancestor，whowasforgingontowardscivilization，hadlearnedtocounthisfingersandtoes，andtonumberobjectsabouthimbyfivesandtensinconsequence，beforebepassedbeyondtheplaneofnumerousexistingbarbarians。Howmuchbeyondthishehadgoneweneednotattempttoinquire；buttherelativelyhighdevelopmentofmathematicsintheearlyhistoricalperiodsuggeststhatprimevalmanhadattainedanotinconsiderableknowledgeofnumbers。Thehumdrumvocationoflookingafteranumerousprogenymusthavetaughtthemothertherudimentsofadditionandsubtraction；andtheelementsofmultiplicationanddivisionareimpliedinthecapacitytocarryoneventherudestformofbarter，suchasthevarioustribesmusthavepractisedfromanearlyday。
　　Astopoliticalideas，eventhecrudesttriballifewasbasedoncertainconceptionsofownership，atleastoftribalownership，andtheapplicationoftheprincipleoflikenessanddifferencetowhichwehavealreadyreferred。Eachtribe，ofcourse，differedinsomeregardfromothertribes，andtherecognitionofthesedifferencesimpliedinitselfapoliticalclassification。A
　　certaintribetookpossessionofaparticularhunting-ground，whichbecame，forthetimebeing，itshome，andoverwhichitcametoexercisecertainrights。Aninvasionofthisterritorybyanothertribemightleadtowar，andthebandingtogetherofthemembersofthetribetorepeltheinvaderimpliedbotharecognitionofcommunalunityandaspeciesofprejudiceinfavorofthatcommunitythatconstitutedaprimitivepatriotism。Butthisunityofactioninopposinganothertribewouldnotpreventacertainrivalryofinterestbetweenthemembersofthesametribe，whichwouldshowitselfmoreandmoreprominentlyasthetribeincreasedinsize。Theassociationoftwoormorepersonsimplies，always，theascendencyofsomeandthesubordinationofothers。Leadershipandsubordinationarenecessarycorrelativesofdifferenceofphysicalandmentalendowment，andrivalrybetweenleaderswouldinevitablyleadtotheformationofprimitivepoliticalparties。Withtheultimatesuccessandascendencyofoneleader，whosecureseitherabsolutepowerorpowermodifiedinaccordancewiththeadviceofsubordinateleaders，wehavethegermsofanelaboratepoliticalsystem——anembryoscienceofgovernment。
　　Meanwhile，theveryexistenceofsuchacommunityimpliestherecognitiononthepartofitsmembersofcertainindividualrights，therecognitionofwhichisessentialtocommunalharmony。Therightofindividualownershipofthevariousarticlesandimplementsofevery-daylifemustberecognized，orallharmonywouldbeatanend。Certainrulesofjustice——
　　primitivelaws——must，bycommonconsent，giveprotectiontotheweakestmembersofthecommunity。Herearetherudimentsofasystemofethics。Itmayseemanomaloustospeakofthisprimitivemorality，thisearlyrecognitionoftheprinciplesofrightandwrong，ashavinganyrelationtoscience。Yet，rightlyconsidered，thereisnoincongruityinsuchacitation。Therecannotwellbeadoubtthattheadoptionofthosebroadprinciplesofrightandwrongwhichunderlietheentirestructureofmoderncivilizationwasduetoscientificinduction，——inotherwords，tothebelief，basedonobservationandexperience，thattheprinciplesimpliedwereessentialtocommunalprogress。Hewhohasscannedthepageantofhistoryknowshowoftentheseprinciplesseemtobeabsentintheintercourseofmenandnations。Yettheidealisalwaysthereasastandardbywhichalldeedsarejudged。
　　Itwouldappear，then，thattheentiresuperstructureoflatersciencehaditsfoundationintheknowledgeandpracticeofprehistoricman。Thecivilizationofthehistoricalperiodcouldnothaveadvancedasithashadtherenotbeencountlessgenerationsofculturebackofit。Thenewprinciplesofsciencecouldnothavebeenevolvedhadtherenotbeengreatbasalprincipleswhichagesofunconsciousexperimenthadimpresseduponthemindofourrace。Duemeedofpraisemustbegiven，then，toourprimitiveancestorforhisscientificaccomplishments；butjusticedemandsthatweshouldlookalittlefartherandconsiderthereversesideofthepicture。Wehavehadtodo，thusfar，chieflywiththepositivesideofaccomplishment。Wehavepointedoutwhatourprimitiveancestorknew，intimating，perhaps，thelimitationsofhisknowledge；butwehavehadlittletosayofoneall-importantfeatureofhisscientifictheorizing。Thefeatureinquestionisbasedonthehighlyscientificdesireandpropensitytofindexplanationsforthephenomenaofnature。Withoutsuchdesirenoprogresscouldbemade。Itis，aswehaveseen，thegeneralizingfromexperiencethatconstitutesrealscientificprogress；andyet，justasmostothergoodthingscanbeoverdone，thisscientificpropensitymaybecarriedtoadisastrousexcess。
　　Primevalmandidnotescapethisdanger。Heobserved，hereasoned，hefoundexplanations；buthedidnotalwaysdiscriminateastothelogicalityofhisreasonings。Hefailedtorecognizethelimitationsofhisknowledge。Theobserveduniformityinthesequenceofcertaineventsimpressedonhismindtheideaofcauseandeffect。Proximatecausesknown，hesoughtremotercauses；childlike，hisinquiringmindwasalwaysasking，Why？and，childlike，hedemandedanexplicitanswer。Iftheforcesofnatureseemedtocombathim，ifwindandrainopposedhisprogressandthunderandlightningseemedtomenacehisexistence，hewasledirrevocablytothinkofthosehumanfoeswhowarredwithhim，andtosee，backofthewarfareoftheelements，aninscrutablemalevolentintelligencewhichtookthismethodtoexpressitsdispleasure。Buteveryotherlineofscientificobservationleadsequally，followingbackasequenceofevents，toseeminglycauselessbeginnings。Modernsciencecanexplainthelightning，asitcanexplainagreatnumberofthemysterieswhichtheprimevalintelligencecouldnotpenetrate。
　　Buttheprimordialmancouldnotwaitfortherevelationsofscientificinvestigation:hemustvaultatoncetoafinalsolutionofallscientificproblems。Hefoundhissolutionbypeoplingtheworldwithinvisibleforces，anthropomorphicintheirconception，likehimselfintheirthoughtandaction，differingonlyinthelimitationsoftheirpowers。Hisowndreamexistencegavehimseemingproofoftheexistenceofanalterego，aspiritualportionofhimselfthatcoulddisseveritselffromhisbodyandwanderatwill；hisscientificinductionsseemedtotellhimofaworldofinvisiblebeings，capableofinfluencinghimforgoodorill。Fromthescientificexerciseofhisfacultiesheevolvedtheall-encompassinggeneralizationsofinvisibleandall-powerfulcausesbackofthephenomenaofnature。Thesegeneralizations，earlydevelopedandseeminglysupportedbytheobservationsofcountlessgenerations，cametobeamongthemostfirmlyestablishedscientificinductionsofourprimevalancestor。Theyobtainedaholduponthementalityofourracethatledsubsequentgenerationstothinkofthem，sometimestospeakofthem，as"innate"ideas。Theobservationsuponwhichtheywerebasedarenow，forthemostpart，susceptibleofotherinterpretations；buttheoldinterpretationshaveprecedentandprejudicebackofthem，andtheyrepresentideasthataremoredifficultthanalmostanyotherstoeradicate。Always，andeverywhere，superstitionsbaseduponunwarrantedearlyscientificdeductionshavebeenthemostimplacablefoestotheprogressofscience。Menhavebuiltsystemsofphilosophyaroundtheirconceptionofanthropomorphicdeities；theyhavelinkedtothesesystemsofphilosophythealliedconceptionoftheimmutabilityofman’sspirit，andtheyhaveaskedthatscientificprogressshouldstopshortatthebrinkofthesesystemsofphilosophyandaccepttheirdictatesasfinal。Yetthereisnotto-dayinexistence，andthereneverhasbeen，onejotofscientificevidencefortheexistenceoftheseintangibleanthropomorphicpowersbackofnaturethatisnotsusceptibleofscientificchallengeandofmorelogicalinterpretation。Indespiteofwhichthesuperstitiousbeliefsarestillasfirmlyfixedinthemindsofalargemajorityofourraceastheywereinthemindofourprehistoricancestor。Thefactofthisbalefulheritagemustnotbeforgotteninestimatingthedebtofgratitudewhichhistoricmanowestohisbarbaricpredecessor。
　　Inthepreviouschapterwehavepurposelyrefrainedfromreferringtoanyparticulartribeorraceofhistoricalman。Now，however，weareatthebeginningsofnationalexistence，andwehavetoconsidertheaccomplishmentsofanindividualrace；orrather，perhaps，oftwoormoreracesthatoccupiedsuccessivelythesamegeographicalterritory。Butevennowourstudiesmustforatimeremainverygeneral；weshallseelittleornothingofthedeedsofindividualscientistsinthecourseofourstudyofEgyptianculture。Wearestill，itmustbeunderstood，atthebeginningsofhistory；indeed，wemustfirstbridgeoverthegapfromtheprehistoricbeforewemayfindourselvesfairlyonthelineofmarchofhistoricalscience。
　　Attheveryoutsetwemaywellaskwhatconstitutesthedistinctionbetweenprehistoricandhistoricepochs——adistinctionwhichhasbeenconstantlyimpliedinmuchthatwehavesaid。Thereplysavorssomewhatofvagueness。Itisadistinctionhavingtodo，notsomuchwithfactsofhumanprogressaswithourinterpretationofthesefacts。Whenwespeakofthedawnofhistorywemustnotbeunderstoodtoimplythat，attheperiodinquestion，therewasanysuddenchangeintheintellectualstatusofthehumanraceorinthestatusofanyindividualtribeornationofmen。Whatwemeanisthatmodernknowledgehaspenetratedthemistsofthepastfortheperiodwetermhistoricalwithsomethingmoreofclearnessandprecisionthanithasbeenabletobringtobearuponyetearlierperiods。
　　Newaccessionsofknowledgemaythusshiftfromtimetotimetheboundsoftheso-calledhistoricalperiod。TheclearestillustrationofthisisfurnishedbyourinterpretationofEgyptianhistory。UntilrecentlythebiblicalrecordsoftheHebrewcaptivityorservice，togetherwiththesimilaraccountofJosephus，furnishedaboutallthatwasknownofEgyptianhistoryevenofsocomparativelyrecentatimeasthatofRamsesII。
　　fifteenthcenturyB。C。，andfromthatperiodontherewasalmostacompletegapuntilthestorywastakenupbytheGreekhistoriansHerodotusandDiodorus。Itistruethattheking-listsoftheAlexandrianhistorian，Manetho，wereallalongaccessibleinsomewhatgarbledcopies。Butatbesttheyseemedtosupplyunintelligiblelistsofnamesanddateswhichnoonewasdisposedtotakeseriously。Thattheywere，broadlyspeaking，truehistoricalrecords，andmostimportanthistoricalrecordsatthat，wasnotrecognizedbymodernscholarsuntilfreshlighthadbeenthrownonthesubjectfromaltogethernewsources。
　　Thesenewsourcesofknowledgeofancienthistorydemandamoment’sconsideration。Theyareall-importantbecausetheyhavebeenthemeansofextendingthehistoricalperiodofEgyptianhistoryusingthewordhistoryinthewayjustexplainedbythreeorfourthousandyears。Asjustsuggested，thathistoricalperiodcarriedthescholarshipoftheearlynineteenthcenturyscarcelybeyondthefifteenthcenturyB。C。，butto-day’svisionextendswithtolerableclearnesstoaboutthemiddleofthefifthmillenniumB。C。ThischangehasbeenbroughtaboutchieflythroughstudyoftheEgyptianhieroglyphics。Thesehieroglyphicsconstitute，aswenowknow，ahighlydevelopedsystemofwriting；
　　asystemthatwaspractisedforsomethousandsofyears，butwhichfellutterlyintodisuseinthelaterRomanperiod，andtheknowledgeofwhichpassedabsolutelyfromthemindofman。Forabouttwothousandyearsnoonewasabletoread，withanydegreeofexplicitness，asinglecharacterofthisstrangescript，andtheideabecameprevalentthatitdidnotconstitutearealsystemofwriting，butonlyamoreorlessbarbaricsystemofreligioussymbolism。ThefalsityofthisviewwasshownearlyinthenineteenthcenturywhenDr。ThomasYoungwasled，throughstudyofthefamoustrilingualinscriptionoftheRosettastone，tomakethefirstsuccessfulattemptatclearingupthemysteriesofthehieroglyphics。
　　Thisisnottheplacetotellthestoryofhisfascinatingdiscoveriesandthoseofhissuccessors。Thatstorybelongstonineteenth-centuryscience，nottothescienceoftheEgyptians。
　　SufficeitherethatYounggainedthefirstclewtoafewofthephoneticvaluesoftheEgyptiansymbols，andthattheworkofdiscoverywascarriedonandvastlyextendedbytheFrenchmanChampollion，alittlelater，withtheresultthatthefirmfoundationsofthemodernscienceofEgyptologywerelaid。
　　SubsequentlysuchstudentsasRosellinitheItalian，LepsiustheGerman，andWilkinsontheEnglishman，enteredthefield，whichinduecoursewascultivatedbyDeRougeinFranceandBirchinEngland，andbysuchdistinguishedlatter-dayworkersasChabas，Mariette，Maspero，Amelineau，andDeMorganamongtheFrenchmen；
　　ProfessorPetrieandDr。BudgeinEngland；andBrugschPashaandProfessorErmaninGermany，nottomentionalargecoterieofsomewhatlessfamiliarnames。Thesemenworking，someoftheminthefieldofpracticalexploration，someasstudentsoftheEgyptianlanguageandwriting，haverestoredtousatolerablypreciseknowledgeofthehistoryofEgyptfromthetimeofthefirsthistoricalking，Mena，whosedateisplacedataboutthemiddleofthefifthcenturyB。C。Weknownotmerelythenamesofmostofthesubsequentrulers，butsomethingofthedeedsofmanyofthem；and，whatisvastlymoreimportant，weknow，thankstothemoderninterpretationoftheoldliterature，manythingsconcerningthelifeofthepeople，andinparticularconcerningtheirhighestculture，theirmethodsofthought，andtheirscientificattainments，whichmightwellhavebeensupposedtobepastfindingout。Norhasmoderninvestigationhaltedwiththetimeofthefirstkings；therecentexplorationsofsucharchaeologistsasAmelineau，DeMorgan，andPetriehavebroughttolightnumerousremainsofwhatisnowspokenofasthepredynasticperiod——aperiodwhentheinhabitantsoftheNileValleyusedimplementsofchippedstone，whentheirpotterywasmadewithouttheuseofthepotter’swheel，andwhentheyburiedtheirdeadincuriouslycrampedattitudeswithoutattemptatmummification。TheseaboriginalinhabitantsofEgyptcannotperhapswithstrictproprietybespokenofaslivingwithinthehistoricalperiod，sincewecannotdatetheirrelicswithanyaccuracy。ButtheygiveusglimpsesoftheearlystagesofcivilizationuponwhichtheEgyptiansofthedynasticperiodweretoadvance。
　　ItisheldthatthenascentcivilizationoftheseEgyptiansoftheNeolithic，orlateStoneAge，wasoverthrownbytheinvadinghostsofamorehighlycivilizedracewhichprobablycamefromtheEast，andwhichmayhavebeenofaSemiticstock。Thepresumptionisthatthisinvadingpeoplebroughtwithitaknowledgeoftheartsofwarandpeace，developedoradoptedinitsoldhome。Theintroductionoftheseartsservedtobridgesomewhatsuddenly，sofarasEgyptisconcerned，thatgapbetweentheprehistoricandthehistoricstageofculturetowhichwehaveallalongreferred。Theessentialstructureofthatbridge，letitnowbeclearlyunderstood，consistedofasingleelement。
　　Thatelementisthecapacitytomakewrittenrecords:aknowledgeoftheartofwriting。Clearlyunderstood，itisthiselementofknowledgethatformsthelineboundingthehistoricalperiod。
　　Numberlessmementosareinexistencethattelloftheintellectualactivitiesofprehistoricman；suchmementosasflintimplements，piecesofpottery，andfragmentsofbone，inscribedwithpicturesthatmayfairlybespokenofasworksofart；butsolongasnowrittenwordaccompaniestheserecords，solongasnonameofkingorscribecomesdowntous，wefeelthattheserecordsbelongtothedomainofarchaeologyratherthantothatofhistory。Yetitmustbeunderstoodallalongthatthesetwodomainsshadeoneintotheotherand，ithasalreadybeenurged，thatthedistinctionbetweenthemisonethatpertainsrathertomodernscholarshipthantothedevelopmentofcivilizationitself。Bearingthisdistinctionstillinmind，andrecallingthatthehistoricalperiod，whichistobethefieldofourobservationthroughouttherestofourstudies，extendsforEgyptwellbackintothefifthmillenniumB。C。，letusbrieflyreviewthepracticalphasesofthatcivilizationtowhichtheEgyptianhadattainedbeforethebeginningofthedynasticperiod。Sincetheoreticalscienceiseverywherelinkedwiththemechanicalarts，thissurveywillgiveusaclearcomprehensionofthefieldthatliesopenfortheprogressofscienceinthelongstagesofhistoricaltimeuponwhichwearejustentering。
　　Wemaypassoversuchrudimentaryadvancesinthedirectionofcivilizationasareimpliedintheuseofarticulatelanguage，theapplicationoffiretotheusesofman，andthesystematicmakingofdwellingsofonesortoranother，sinceallofthesearestagesofprogressthatwerereachedveryearlyintheprehistoricperiod。WhatmoredirectlyconcernsusistonotethatareallyhighstageofmechanicaldevelopmenthadbeenreachedbeforethedawningsofEgyptianhistoryproper。Allmannerofhouseholdutensilswereemployed；thepotter’swheelaidedintheconstructionofagreatvarietyofearthenvessels；
　　weavinghadbecomeafineart，andweaponsofbronze，includingaxes，spears，knives，andarrow-heads，wereinconstantuse。
　　Animalshadlongbeendomesticated，inparticularthedog，thecat，andtheox；thehorsewasintroducedlaterfromtheEast。
　　ThepracticalartsofagriculturewerepractisedalmostastheyareatthepresentdayinEgypt，therebeing，ofcourse，thesamedependencethenasnowupontheinundationsoftheNile。
　　Astogovernment，theEgyptianofthefirstdynastyregardedhiskingasademi-godtobeactuallydeifiedafterhisdeath，andthispointofviewwasnotchangedthroughoutthestagesoflaterEgyptianhistory。Inpointofart，marvellousadvancesupontheskilloftheprehistoricmanhadbeenmade，probablyinpartunderAsiaticinfluences，andthatuniquestyleofstiltedyetexpressivedrawinghadcomeintovogue，whichwastoberememberedinaftertimesastypicallyEgyptian。Moreimportantthanallelse，ourEgyptianoftheearliesthistoricalperiodwasinpossessionoftheartofwriting。HehadbeguntomakethosespecificrecordswhichwereimpossibletothemanoftheStoneAge，andthushehadenteredfullyuponthewayofhistoricalprogresswhich，asalreadypointedout，hasitsveryfoundationinwrittenrecords。Fromnowonthedeedsofindividualkingscouldfindspecificrecord。Itbegantobepossibletofixthechronologyofremoteeventswithsomeaccuracy；andwiththissamefixingofchronologiescametheadventoftruehistory。TheperiodwhichprecedeswhatisusuallyspokenofasthefirstdynastyinEgyptisoneintowhichthepresent-daysearcherisstillabletoseebutdarkly。TheevidenceseemstosuggestthananinvasionofrelativelyculturedpeoplefromtheEastoverthrew，andintimesupplanted，theNeolithiccivilizationoftheNileValley。Itisimpossibletodatethisinvasionaccurately，butitcannotwellhavebeenlaterthantheyear5000
　　B。C。，anditmayhavebeenagreatmanycenturiesearlierthanthis。Betheexactdateswhattheymay，wefindtheEgyptianofthefifthmillenniumB。C。infullpossessionofahighlyorganizedcivilization。
　　Allsubsequentageshavemarvelledatthepyramids，someofwhichdatefromabouttheyear4000B。C。，thoughwemaynoteinpassingthatthesedatesmustnotbetakentooliterally。ThechronologyofancientEgyptcannotasyetbefixedwithexactaccuracy，butthedisagreementsbetweenthevariousstudentsofthesubjectneedgiveuslittleconcern。Forourpresentpurposeitdoesnotintheleastmatterwhetherthepyramidswerebuiltthreethousandorfourthousandyearsbeforethebeginningofourera。
　　ItsufficesthattheydatebacktoaperiodlongantecedenttothebeginningsofcivilizationinWesternEurope。TheyprovethattheEgyptianofthatearlydayhadattainedaknowledgeofpracticalmechanicswhich，evenfromthetwentieth-centurypointofview，isnottobespokenoflightly。Ithassometimesbeensuggestedthatthesemightypyramids，builtastheyareofgreatblocksofstone，speakforanalmostmiraculousknowledgeonthepartoftheirbuilders；butasanerviewoftheconditionsgivesnowarrantforthisthought。Diodoras，theSicilian，inhisfamousWorld’sHistory，writtenaboutthebeginningofourera，explainsthebuildingofthepyramidsbysuggestingthatgreatquantitiesofearthwerepiledagainstthesideoftherisingstructuretoformaninclinedplaneupwhichtheblocksofstoneweredragged。Hegivesuscertainfigures，based，doubtless，onreportsmadetohimbyEgyptianpriests，whointurndrewuponthetraditionsoftheircountry，perhapsevenuponwrittenrecordsnolongerpreserved。Hesaysthatonehundredandtwentythousandmenwereemployedintheconstructionofthelargestpyramid，andthat，notwithstandingthesizeofthishostofworkers，thetaskoccupiedtwentyyears。Wemustnotplacetoomuchdependenceuponsuchfiguresasthese，fortheancienthistoriansarenotoriouslygiventoexaggerationinrecordingnumbers；yetweneednotdoubtthatthereportgivenbyDiodorusissubstantiallyaccurateinitsmainoutlinesastothemethodthroughwhichthepyramidswereconstructed。Ahostofmenputtingtheiraddedweightandstrengthtothetask，withtheaidofropes，pulleys，rollers，andlevers，andutilizingtheprincipleoftheinclinedplane，couldundoubtedlymoveandelevateandplaceinpositionthelargestblocksthatenterintothepyramidsor——whatseemsevenmorewonderful——themostgiganticobelisks，withouttheaidofanyotherkindofmechanismorofanymoreoccultpower。Thesamehandscould，asDiodorussuggests，removealltraceofthedebrisofconstructionandleavethepyramidsandobelisksstandinginweirdisolation，asifsprungintobeingthroughamiracle。
　　IthasbeennecessarytobearinmindthesephasesofpracticalcivilizationbecausemuchthatweknowofthepurelyscientificattainmentsoftheEgyptiansisbaseduponmodernobservationoftheirpyramidsandtemples。Itwasearlyobserved，forexample，thatthepyramidsareobviouslyorientedasregardsthedirectioninwhichtheyface，instrictaccordancewithsomeastronomicalprinciple。EarlyinthenineteenthcenturytheFrenchmanBiotmadeinterestingstudiesinregardtothissubject，andahundredyearslater，inourowntime，SirJosephNormanLockyer，followinguptheworkofvariousintermediaryobservers，hasgiventhesubjectmuchattention，makingitthecentralthemeofhisworkonTheDawnofAstronomy。[1]Lockyer’sresearchesmakeitclearthatinthemainthetemplesofEgyptwereorientedwithreferencetothepointatwhichthesunrisesonthedayofthesummersolstice。ThetimeofthesolsticehadpeculiarinterestfortheEgyptians，becauseitcorrespondedrathercloselywiththetimeoftherisingoftheNile。Thefloodsofthatriverappearwithverygreatregularity；theon-rushingtidereachestheregionofHeliopolisandMemphisalmostpreciselyonthedayofthesummersolstice。Thetimevariesatdifferentstagesoftheriver’scourse，butasthecivilizationoftheearlydynastiescentredatMemphis，observationsmadeatthisplacehadwidestvogue。
　　Consideringtheall-essentialcharacteroftheNilefloods-withoutwhichcivilizationwouldbeimpossibleinEgypt——itisnotstrangethatthetimeoftheirappearanceshouldbetakenasmarkingthebeginningofanewyear。Thefactthattheircomingcoincideswiththesolsticemakessuchadivisionofthecalendarperfectlynatural。Inpointoffact，fromtheearliestperiodsofwhichrecordshavecomedowntous，thenewyearoftheEgyptiansdatesfromthesummersolstice。ItiscertainthatfromtheearliesthistoricalperiodstheEgyptianswereawareoftheapproximatelengthoftheyear。Itwouldbestrangewereitotherwise，consideringtheeasewithwhicharecordofdayscouldbekeptfromNilefloodtoNileflood，orfromsolsticetosolstice。Butthis，ofcourse，appliesonlytoanapproximatecount。ThereissomereasontobelievethatintheearliestperiodtheEgyptiansmadethiscountonly360days。Thefactthattheiryearwasdividedintotwelvemonthsofthirtydayseachlendscolortothisbelief；but，inanyevent，themistakewasdiscoveredinduetimeandapartialremedywasappliedthroughtheinterpolationofa"littlemonth"offivedaysbetweentheendofthetwelfthmonthandthenewyear。Thisnearlybutnotquiteremediedthematter。Whatitobviouslyfailedtodowastotakeaccountofthatadditionalquarterofadaywhichreallyroundsouttheactualyear。
　　Itwouldhavebeenavastlyconvenientthingforhumanityhaditchancedthattheearthhadsoaccommodateditsrotarymotionwithitsspeedoftransitaboutthesunastomakeitsannualflightinprecisely360days。Twelvelunarmonthsofthirtydayseachwouldthenhavecoincidedexactlywiththesolaryear，andmostofthecomplexitiesofthecalendar，whichhavesopuzzledhistoricalstudents，wouldhavebeenavoided；but，ontheotherhand，perhapsthisverysimplicitywouldhaveproveddetrimentaltoastronomicalsciencebypreventingmenfromsearchingtheheavensascarefullyastheyhavedone。Bethatasitmay，thecomplexityexists。Theactualyearofthreehundredandsixty-fiveandaboutone-quarterdayscannotbedividedevenlyintomonths，andsomesuchexpedientastheintercalationofdayshereandthereisessential，elsethecalendarwillbecomeabsolutelyoutofharmonywiththeseasons。
　　InthecaseoftheEgyptians，theattemptatadjustmentwasmade，asjustnoted，bytheintroductionofthefivedays，constitutingwhattheEgyptiansthemselvestermed"thefivedaysoverandabovetheyear。"Theseso-calledepagomenaldayswereundoubtedlyintroducedataveryearlyperiod。MasperoholdsthattheywereinusebeforethefirstThinitedynasty，citinginevidencethefactthatthelegendofOsirisexplainsthesedaysashavingbeencreatedbythegodThotinordertopermitNuittogivebirthtoallherchildren；thisexpedientbeingnecessarytoovercomeabanwhichhadbeenpronouncedagainstNuit，accordingtowhichshecouldnotgivebirthtochildrenonanydayoftheyear。But，ofcourse，thefiveadditionaldaysdonotsufficefullytorectifythecalendar。Thereremainstheadditionalquarterofadaytobeaccountedfor。This，ofcourse，amountstoafulldayeveryfourthyear。WeshallseethatlaterAlexandriansciencehitupontheexpedientofaddingadaytoeveryfourthyear；anexpedientwhichtheJuliancalendaradoptedandwhichstillgivesusourfamiliarleap-year。But，unfortunately，theancientEgyptianfailedtorecognizetheneedofthisadditionalday，orifhedidrecognizeithefailedtoactonhisknowledge，andsoithappenedthat，startingsomewherebackintheremotepastwithanewyear’sdaythatcoincidedwiththeinundationoftheNile，therewasaconstantlyshiftingmaladjustmentofcalendarandseasonsastimewenton。
　　TheEgyptianseasons，itshouldbeexplained，werethreeinnumber:theseasonoftheinundation，theseasonoftheseed-time，andtheseasonoftheharvest；eachseasonbeing，ofcourse，fourmonthsinextent。Originally，asjustmentioned，theseasonoftheinundationsbeganandcoincidedwiththeactualtimeofinundation。Themoreprecisefixingofnewyear’sdaywasaccomplishedthroughobservationofthetimeoftheso-calledheliacalrisingofthedog-star，Sirius，whichboretheEgyptiannameSothis。Itchancesthat，asviewedfromabouttheregionofHeliopolis，thesunatthetimeofthesummersolsticeoccupiesanapparentpositionintheheavensclosetothedog-star。Now，asiswellknown，theEgyptians，seeingdivinitybackofalmosteveryphenomenonofnature，verynaturallypaidparticularreverencetosoobviouslyinfluentialapersonageasthesun-god。
　　InparticulartheythoughtitfittingtodohomagetohimjustashewasstartingoutonhistourofEgyptinthemorning；andthattheymightknowtheprecisemomentofhiscoming，theEgyptianastronomerpriests，perchedonthehill-topsneartheirtemples，werewonttoscantheeasternhorizonwithreferencetosomestarwhichhadbeenobservedtoprecedethesolarluminary。Ofcoursetheprecessionoftheequinoxes，duetothataxialwobbleinwhichourclumsyearthindulges，wouldchangetheapparentpositionofthefixedstarsinreferencetothesun，sothatthesamestarcouldnotdoserviceasheliacalmessengerindefinitely；but，ontheotherhand，thesechangesaresoslowthatobservationsbymanygenerationsofastronomerswouldberequiredtodetecttheshifting。ItisbelievedbyLockyer，thoughtheevidenceisnotquitedemonstrative，thattheastronomicalobservationsoftheEgyptiansdatebacktoaperiodwhenSothis，thedog-star，wasnotincloseassociationwiththesunonthemorningofthesummersolstice。Yet，accordingtothecalculationsofBiot，theheliacalrisingofSothisatthesolsticewasnotedasearlyastheyear3285B。C。，anditiscertainthatthisstarcontinuedthroughoutsubsequentcenturiestokeepthispositionofpeculiarprestige。HenceitwasthatSothiscametobeassociatedwithIsis，oneofthemostimportantdivinitiesofEgypt，andthatthedayinwhichSothiswasfirstvisibleinthemorningskymarkedthebeginningofthenewyear；
　　thatdaycoinciding，asalreadynoted，withthesummersolsticeandwiththebeginningoftheNileflow。
　　Butnowforthedifficultiesintroducedbythatunreckonedquarterofaday。Obviouslywithacalendarof365daysonly，attheendoffouryears，thecalendaryear，orvagueyear，astheEgyptianscametocallit，hadgainedbyonefulldayupontheactualsolaryear——thatistosay，theheliacalrisingofSothis，thedog-star，wouldnotoccuronnewyear’sdayofthefaultycalendar，butadaylater。Andwitheachsucceedingperiodoffouryearsthedayofheliacalrising，whichmarkedthetruebeginningoftheyear——andwhichstill，ofcourse，coincidedwiththeinundation——wouldhavefallenanotherdaybehindthecalendar。Inthecourseof120yearsanentiremonthwouldbelost；andin480yearssogreatwouldbecometheshiftingthattheseasonswouldbealtogethermisplaced；theactualtimeofinundationscorrespondingwithwhatthecalendarregisteredastheseed-time，andtheactualseed-timeinturncorrespondingwiththeharvest-timeofthecalendar。
　　Atfirstthoughtthisseemsveryawkwardandconfusing，butinallprobabilitytheeffectswerebynomeanssomuchsoinactualpractice。Weneedgonofartherthantoourownexperiencetoknowthatthenamesofseasons，asofmonthsanddays，cometohaveinthemindsofmostofusapurelyconventionalsignificance。FewofusstoptogiveathoughttothemeaningofthewordsJanuary，February，etc。，exceptastheyconnotecertainclimaticconditions。If，then，ourowncalendarweresodefectivethatinthecourseof120yearsthemonthofFebruaryhadshiftedbacktooccupythepositionoftheoriginalJanuary，thechangewouldhavebeensogradual，coveringtheperiodoftwolife-timesoroffourorfiveaveragegenerations，thatitmightwellescapegeneralobservation。
　　EachsucceedinggenerationofEgyptians，then，maynotimprobablyhaveassociatedthenamesoftheseasonswiththecontemporaryclimaticconditions，troublingthemselveslittlewiththethoughtthatinanearlieragetheclimaticconditionsforeachperiodofthecalendarwerequitedifferent。Wecannotwellsuppose，however，thattheastronomerpriestswereoblivioustothetruestateofthings。UponthemdevolvedthedutyofpredictingthetimeoftheNileflood；adutytheywereenabledtoperformwithoutdifficultythroughobservationoftherisingofthesolstitialsunanditsSothicmessenger。Totheseobserversitmustfinallyhavebeenapparentthattheshiftingoftheseasonswasattherateofonedayinfouryears；thisknown，itrequirednogreatmathematicalskilltocomputethatthisshiftingwouldfinallyeffectacompletecircuitofthecalendar，sothatafter4X365=1460yearsthefirstdayofthecalendaryearwouldagaincoincidewiththeheliacalrisingofSothisandwiththecomingoftheNileflood。Inotherwords，1461vagueyearsorEgyptiancalendaryearsOf365dayseachcorrespondto1460
　　actualsolaryearsof3651/4dayseach。Thisperiod，measuredthusbytheheliacalrisingofSothis，isspokenofastheSothiccycle。
　　Touswhoaretrainedfromchildhoodtounderstandthattheyearconsistsofapproximately3651/4days，andtoknowthatthecalendarmayberegulatedapproximatelybytheintroductionofanextradayeveryfourthyear，thisrecognitionoftheSothiccycleseemssimpleenough。Yetiftheaveragemanofuswillreflecthowlittleheknows，ofhisownknowledge，oftheexactlengthoftheyear，itwillsoonbecomeevidentthattheappreciationofthefaultsofthecalendarandtheknowledgeofitsperiodicaladjustmentconstitutedarelativelyhighdevelopmentofscientificknowledgeonthepartoftheEgyptianastronomer。ItmaybeaddedthatvariouseffortstoreformthecalendarweremadebytheancientEgyptians，butthattheycannotbecreditedwithasatisfactorysolutionoftheproblem；for，ofcourse，theAlexandrianscientistsofthePtolemaicperiodwhoseworkweshallhaveoccasiontoreviewpresentlywerenotEgyptiansinanypropersenseoftheword，butGreeks。
　　Sincesomuchofthetimeoftheastronomerpriestswasdevotedtoobservationoftheheavenlybodies，itisnotsurprisingthattheyshouldhavemappedouttheapparentcourseofthemoonandthevisibleplanetsintheirnightlytouroftheheavens，andthattheyshouldhavedividedthestarsofthefirmamentintomoreorlessarbitrarygroupsorconstellations。Thattheydidsoisevidencedbyvarioussculpturedrepresentationsofconstellationscorrespondingtosignsofthezodiacwhichstillornamenttheceilingsofvariousancienttemples。Unfortunatelythedecorativesense，whichwasalwayspredominantwiththeEgyptiansculptor，ledhimtotakevariouslibertieswiththedistributionoffiguresintheserepresentationsoftheconstellations，sothattheinferencesdrawnfromthemastotheexactmapoftheheavensastheEgyptiansconceiveditcannotbefullyreliedupon。Itappears，however，thattheEgyptianastronomerdividedthezodiacintotwenty-fourdecani，orconstellations。Thearbitrarygroupingsoffigures，withtheaidofwhichthesearedelineated，bearacloseresemblancetotheequallyarbitraryoutlineswhichwearestillaccustomedtouseforthesamepurpose。