Subsequentgenerations，however，putthisinterpretationuponthetheory，conceivingthevariousspheresasactualcrystallinebodies。Itisdifficulttoimaginejusthowthevariousepicyclesweresupposedtorevolvewithoutinterferingwiththemajorspheres，butperhapsthisisnogreaterdifficultythanispresentedbytheallegedpropertiesoftheether，whichphysicistsofto-dayacceptasatleastaworkinghypothesis。Weshallseelateronhowfirmlytheconceptionofconcentriccrystallinesphereswasheldto，andthatnorealchallengewasevergiventhattheoryuntilthediscoverywasmadethatcometshaveanorbitthatmustnecessarilyintersectthespheresofthevariousplanets。
Ptolemy’ssystemofgeographyineightbooks，foundedonthatofMarinusofTyre，wasscarcelylesscelebratedthroughouttheMiddleAgesthantheAlmagest。Itcontainedlittle，however，thatneedconcernushere，beingratheranelaborationofthedoctrinestowhichwehavealreadysufficientlyreferred。NoneofPtolemy’soriginalmanuscriptshascomedowntous，butthereisanallegedfifth-centurymanuscriptattributedtoAgathadamonofAlexandriawhichhaspeculiarinterestbecauseitcontainsaseriesoftwenty-sevenelaboratelycoloredmapsthataresupposedtobederivedfrommapsdrawnupbyPtolemyhimself。Inthesemapstheseaiscoloredgreen，themountainsredordarkyellow，andthelandwhite。Ptolemyassumedthatadegreeattheequatorwas500stadiainsteadof604stadiainlength。Wearenotinformedastothegroundsonwhichthisassumptionwasmade，butithasbeensuggestedthattheerrorwasatleastpartiallyinstrumentalinleadingtooneverycuriousresult。\"TakingtheparallelofRhodes，\"saysDonaldson，[5]\"hecalculatedthelongitudesfromtheFortunateIslandstoCattigaraorthewestcoastofBorneoat180degrees，conceivingthistobeone-halfthecircumferenceoftheglobe。Therealdistanceisonly125
degreesor127degrees，sothathismeasurementiswrongbyonethirdofthewhole，one-sixthfortheerrorinthemeasurementofadegreeandone-sixthfortheerrorsinmeasuringthedistancegeometrically。Theseerrors，owingtotheauthorityattributedtothegeographyofPtolemyintheMiddleAges，producedaconsequenceofthegreatestimportance。TheyreallyledtothediscoveryofAmerica。ForthedesignofColumbustosailfromthewestofEuropetotheeastofAsiawasfoundedonthesuppositionthatthedistancewaslessbyonethirdthanitreallywas。\"Thisviewisperhapsatriflefanciful，sincethereisnothingtosuggestthatthecourageofColumbuswouldhavebalkedatthegreaterdistance，andsincetheprotestsofthesailors，whichnearlythwartedhisefforts，weremadelongbeforethedistanceasestimatedbyPtolemyhadbeencovered；neverthelessitisinterestingtorecallthatthegreatgeographicaldoctrines，uponwhichColumbusmustchieflyhavebasedhisarguments，hadbeenbeforetheworldinanauthoritativeformpracticallyunheededformorethantwelvehundredyears，awaitingachampionwithcourageenoughtoputthemtothetest。
Thereisoneotherfieldofscientificinvestigationtowhichwemustgivebriefattentionbeforeleavingtheantiqueworld。Thisisthefieldofphysiologyandmedicine。InconsideringitweshallhavetodowiththeverylastgreatscientistoftheAlexandrianschool。ThiswasClaudiusGalenus，commonlyknownasGalen，amanwhosefamewasdestinedtoeclipsethatofallotherphysiciansofantiquityexceptHippocrates，andwhosedoctrinesweretohavethesameforceintheirfieldthroughouttheMiddleAgesthatthedoctrinesofAristotlehadforphysicalscience。
ButbeforewetakeupGalen’sspecificlabors，itwillbewelltoinquirebrieflyastothestateofmedicalartandscienceintheRomanworldatthetimewhenthelastgreatphysicianofantiquitycameuponthescene。
TheRomans，itwouldappear，haddonelittleinthewayofscientificdiscoveriesinthefieldofmedicine，but，nevertheless，withtheirpracticalityofmind，theyhadturnedtobetteraccountmanymoreofthescientificdiscoveriesoftheGreeksthandidthediscoverersthemselves。ThepractisingphysiciansinearlyRomeweremostlymenofGreekorigin，whocametothecapitalaftertheoverthrowoftheGreeksbytheRomans。Manyofthemwereslaves，asearningmoneybyeitherbodilyormentallaborwasconsideredbeneaththedignityofaRomancitizen。ThewealthyRomans，whoownedlargeestatesandnumerousslaves，wereinthehabitofpurchasingsomeoftheseslavedoctors，andthussavingmedicalfeesbyhavingthemattendtothehealthoftheirfamilies。
BythebeginningoftheChristianeramedicineasaprofessionhadsadlydegenerated，andinplaceofaclassofphysicianswhopractisedmedicinealongrationalorlegitimatelines，inthefootstepsofthegreatHippocrates，thereappearedgreatnumbersof\"specialists，\"mostofthemcharlatans，whopretendedtopossesssupernaturalinsightinthemethodsoftreatingcertainformsofdisease。ThesephysiciansrightlyearnedthecontemptofthebetterclassofRomans，andweremadetheobjectofmanyattacksbythesatiristsofthetime。Suchspecialiststravelledaboutfromplacetoplaceinmuchthesamemannerastheitinerant\"Indiandoctors\"and\"lightningtooth-extractors\"doto-day。Eye-doctorsseemtohavebeenparticularlynumerous，andtheseweredividedintotwoclasses，eye-surgeonsandeye-doctorsproper。Theeye-surgeonperformedsuchoperationsascauterizingforingrowingeyelashesandoperatingupongrowthsabouttheeyes；whiletheeye-doctorsdependedentirelyuponsalvesandlotions。Theseeye-salveswerefrequentlystampedwiththesealofthephysicianwhocompoundedthem，somethingliketwohundredofthesesealsbeingstillinexistence。Therewerebesidesthesequacks，however，reputableeye-doctorswhomusthavepossessedconsiderableskillinthetreatmentofcertainophthalmias。AmongsomeRomansurgicalinstrumentsdiscoveredatRheimswerefoundalsosomedrugsemployedbyophthalmicsurgeons，andananalysisoftheseshowthattheycontained，amongotheringredients，somethatarestillemployedinthetreatmentofcertainaffectionsoftheeye。
OneofthefirststepstakeninrecognitionoftheservicesofphysicianswasbyJuliusCaesar，whograntedcitizenshiptoallphysicianspractisinginRome。ThiswasaboutfiftyyearsbeforetheChristianera，andfromthattimeontherewasagradualimprovementintheattitudeoftheRomanstowardsthemembersofthemedicalprofession。AstheRomansdegeneratedfromaraceofsturdywarriorsandbecamemoreandmoredepravedphysically，thenecessityforphysiciansmadeitselfmoreevident。Courtphysicians，andphysicians-in-ordinary，werecreatedbytheemperors，aswerealsocityanddistrictphysicians。Intheyear133A。D。Hadriangrantedimmunityfromtaxesandmilitaryservicetophysiciansinrecognitionoftheirpublicservices。
Thecityanddistrictphysicians，knownasthearchiatripopulaires，treatedandcaredforthepoorwithoutremuneration，havingapositionandsalaryfixedbylawandpaidthemsemi-annually。Thesewerehonorablepositions，andthearchiatriwereobligedtogiveinstructioninmedicine，withoutpay，tothepoorstudents。Theywereallowedtoreceivefeesanddonationsfromtheirpatients，butnot，however，untilthedangerfromthemaladywaspast。Speciallawswereenactedtoprotectthem，andanypersonsubjectingthemtoaninsultwasliabletoafine\"notexceedingonethousandpounds。\"
AnexampleofRomanpracticalityisshowninthemethodoftreatinghemorrhage，asdescribedbyAulusCorneliusCelsus53
B。C。to7A。D。。HippocratesandHippocraticwriterstreatedhemorrhagebyapplicationofcold，pressure，styptics，andsometimesbyactualcauterizing；buttheyknewnothingofthesimplemethodofstoppingahemorrhagebyaligaturetiedaroundthebleedingvessel。Celsusnotonlyrecommendedtyingtheendoftheinjuredvessel，butdescribesthemethodofapplyingtwoligaturesbeforethearteryisdividedbythesurgeon——acommonpracticeamongsurgeonsatthepresenttime。Thecutismadebetweenthesetwo，andthushemorrhageisavoidedfromeitherendofthedividedvessel。
AnotherRomansurgeon，Heliodorus，notonlydescribestheuseoftheligatureinstoppinghemorrhage，butalsothepracticeoftorsion——twistingsmallervessels，whichcausestheirliningmembranetocontractinamannerthatproducescoagulationandstopshemorrhage。Itisremarkablethatsosimpleandpracticalamethodastheuseoftheligatureinstoppinghemorrhagecouldhavegoneoutofuse，onceithadbeendiscovered；butduringtheMiddleAgesitwasalmostentirelylostsightof，andwasnotreintroduceduntilthetimeofAmbroisePare，inthesixteenthcentury。
EvenataveryearlyperiodtheRomansrecognizedtheadvantageofsurgicalmethodsonthefieldofbattle。Eachsoldierwassuppliedwithbandages，andwasprobablyinstructedinapplyingthem，somethinginthesamemannerasisdonenowinallmodernarmies。TheRomansalsomadeuseofmilitaryhospitalsandhadestablishedarudebutverypracticalfield-ambulanceservice。
\"Ineverytrooporbandonoftwoorfourhundredmen，eightortenstoutfellowsweredeputedtorideimmediatelybehindthefighting-linetopickupandrescuethewounded，forwhichpurposetheirsaddleshadtwostirrupsontheleftside，whiletheythemselveswereprovidedwithwater-flasks，andperhapsappliedtemporarybandages。Theywereencouragedbyarewardofapieceofgoldforeachmantheyrescued。’Noscomi’weremalenursesattachedtothemilitaryhospitals，butnotinscribed’onstrength’ofthelegions，andwereprobablyforthemostpartoftheservileclass。\"[6]
FromthetimeoftheearlyAlexandrians，HerophilusandErasistratus，whoseworkwehavealreadyexamined，therehadbeenvariousanatomistsofsomeimportanceintheAlexandrianschool，thoughnonequiteequaltotheseearlierworkers。Thebest-knownnamesarethoseofCelsusofwhomwehavealreadyspoken，whocontinuedtheworkofanatomicalinvestigation，andMarinus，wholivedduringthereignofNero，andRufusofEphesus。ProbablyallofthesewouldhavebeenbetterrememberedbysucceedinggenerationshadtheireffortsnotbeeneclipsedbythoseofGalen。ThisgreatestofancientanatomistswasbornatPergamusofGreekparents。Hisfather，Nicon，wasanarchitectandamanofconsiderableability。UntilhisfifteenthyeartheyouthfulGalenwasinstructedathome，chieflybyhisfather；butafterthattimehewasplacedundersuitableteachersforinstructioninthephilosophicalsystemsinvogueatthatperiod。Shortlyafterthis，however，thesuperstitiousNicon，followingtheinterpretationsofadream，decidedthathissonshouldtakeupthestudyofmedicine，andplacedhimundertheinstructionofseverallearnedphysicians。
Galenwasatirelessworker，makinglongtoursintoAsiaMinorandPalestinetoimprovehimselfinpharmacology，andstudyinganatomyforsometimeatAlexandria。Heappearstohavebeenfullofthesuperstitionsoftheage，however，andearlyinhiscareermadeanextendedtourintowesternAsiainsearchofthechimerical\"jet-stone\"——astonepossessingthepeculiarqualitiesof\"burningwithabituminousodorandsupposedtopossessgreatpotencyincuringsuchdiseasesasepilepsy，hysteria，andgout。\"
Bythetimehehadreachedhistwenty-eighthyearhehadperfectedhiseducationinmedicineandreturnedtohishomeinPergamus。Evenatthattimehehadacquiredconsiderablefameasasurgeon，andhisfellow-citizensshowedtheirconfidenceinhisabilitybychoosinghimassurgeontothewoundedgladiatorsshortlyafterhisreturntohisnativecity。Inthesedutieshisknowledgeofanatomyaidedhimgreatly，andheissaidtohavehealedcertainkindsofwoundsthathadpreviouslybaffledthesurgeons。
InthetimeofGalendissectionsofthehumanbodywereforbiddenbylaw，andhewasobligedtoconfinehimselftodissectionsoftheloweranimals。Hehadtheadvantage，however，oftheanatomicalworksofHerophilusandErasistratus，andhemusthavedependedupontheminperfectinghiscomparisonbetweentheanatomyofmenandtheloweranimals。Itispossiblethathedidmakehumandissectionssurreptitiously，butofthiswehavenoproof。
Hewasfamiliarwiththecomplicatedstructureofthebonesofthecranium。Hedescribedthevertebraeclearly，dividedthemintogroups，andnamedthemafterthemannerofanatomistsofto-day。Hewaslessaccurateinhisdescriptionofthemuscles，althoughalargenumberoftheseweredescribedbyhim。LikeallanatomistsbeforethetimeofHarvey，hehadaveryerroneousconceptionofthecirculation，althoughheunderstoodthattheheartwasanorganforthepropulsionofblood，andheshowedthatthearteriesofthelivinganimalsdidnotcontainairalone，aswastaughtbymanyanatomists。Heknew，also，thattheheartwasmadeupoflayersoffibresthatranincertainfixeddirections——thatis，longitudinal，transverse，andoblique；buthedidnotrecognizetheheartasamuscularorgan。Inproofofthishepointedoutthatallmusclesrequirerest，andastheheartdidnotrestitcouldnotbecomposedofmusculartissue。
Manyofhisphysiologicalexperimentswereconducteduponscientificprinciples。Thusheprovedthatcertainmuscleswereunderthecontrolofdefinitesetsofnervesbycuttingthesenervesinlivinganimals，andobservingthatthemusclessuppliedbythemwererendereduseless。Hepointedoutalsothatnerveshavenopowerinthemselves，butmerelyconductimpulsestoandfromthebrainandspinal-cord。Heturnedthispeculiarknowledgetoaccountinthecaseofacelebratedsophist，Pausanias，whohadbeenunderthetreatmentofvariousphysiciansforanumbnessinthefourthandfifthfingersofhislefthand。Thesephysicianshadbeentreatingthisconditionbyapplicationsofpoulticestothehanditself。Galen，beingcalledinconsultation，pointedoutthattheinjurywasprobablynotinthehanditself，butintheulnernerve，whichcontrolssensationinthefourthandfifthfingers。Surmisingthatthenervemusthavebeeninjuredinsomeway，hemadecarefulinquiriesofthepatient，whorecalledthathehadbeenthrownfromhischariotsometimebefore，strikingandinjuringhisback。Actinguponthisinformation，Galenappliedstimulatingremediestothesourceofthenerveitself——thatis，tothebundleofnerve-trunksknownasthebrachialplexus，intheshoulder。Tothesurpriseandconfusionofhisfellow-physicians，thismethodoftreatmentprovedeffectiveandthepatientrecoveredcompletelyinashorttime。
AlthoughthefunctionsoftheorgansinthechestwerenotwellunderstoodbyGalen，hewaswellacquaintedwiththeiranatomy。
Heknewthatthelungswerecoveredbythinmembrane，andthattheheartwassurroundedbyasacofverysimilartissue。Hemadeconstantcomparisonsalsobetweentheseorgansindifferentanimals，ashisdissectionswereperformeduponbeastsranginginsizefromamousetoanelephant。Theminutenessofhisobservationsisshownbythefactthathehadnotedanddescribedtheringofbonefoundintheheartsofcertainanimals，suchasthehorse，althoughnotfoundinthehumanheartorinmostanimals。
Hisdescriptionoftheabdominalorganswasingeneralaccurate。
Hehadnotedthattheabdominalcavitywaslinedwithapeculiarsaclikemembrane，theperitoneum，whichalsosurroundedmostoftheorganscontainedinthecavity，andhemadespecialnotethatthismembranealsoenvelopedtheliverinapeculiarmanner。Theexactnessofthelastobservationseemsthemorewonderfulwhenwereflectthatevento-daythemedical，studentfindsacorrectunderstandingofthepositionofthefoldsoftheperitoneumoneofthemostdifficultsubjectsinanatomy。
AsapracticalphysicianhewasheldinthehighestesteembytheRomans。TheEmperorMarcusAureliuscalledhimtoRomeandappointedhimphysician-inordinarytohissonCommodus，andonspecialoccasionsMarcusAureliushimselfcalledinGalenashismedicaladviser。Ononeoccasion，thethreearmysurgeonsinattendanceupontheemperordeclaredthathewasabouttobeattackedbyafever。Galenrelateshow\"onspecialcommandIfelthispulse，andfindingitquitenormal，consideringhisageandthetimeofday，Ideclareditwasnofeverbutadigestivedisorder，duetothefoodhehadeaten，whichmustbeconvertedintophlegmbeforebeingexcreted。Thentheemperorrepeatedthreetimes，’That’stheverything，’andaskedwhatwastobedone。IansweredthatIusuallygaveaglassofwinewithpeppersprinkledonit，butforyoukingsweonlyusethesafestremedies，anditwillsufficetoapplywoolsoakedinhotnardointmentlocally。Theemperororderedthewool，wine，etc。，tobebrought，andIlefttheroom。Hisfeetwerewarmedbyrubbingwithhothands，andafterdrinkingthepepperedwine，hesaidtoPitholaushisson’stutor，’Wehaveonlyonedoctor，andthatanhonestone，’andwentontodescribemeasthefirstofphysiciansandtheonlyphilosopher，forhehadtriedmanybeforewhowerenotonlyloversofmoney，butalsocontentious，ambitious，envious，andmalignant。\"[7]
ItwillbeseenfromthisthatGalenhadafullappreciationofhisownabilitiesasaphysician，butinasmuchassucceedinggenerationsforathousandyearsconcurredintheallegedstatementmadebyMarcusAureliusastohisability，heisperhapsexcusableforhisopenavowalofhisbeliefinhispowers。Hisfaithinhisaccuracyindiagnosisandprognosiswasshownwhenacolleagueoncesaidtohim，\"IhaveusedtheprognosticsofHippocratesaswellasyou。WhycanInotprognosticateaswellasyou？\"TothisGalenreplied，\"ByGod’shelpIhaveneverbeendeceivedinmyprognosis。\"[8]Itisprobablethatthisstatementwasmadeintheheatofargument，anditishardlytobesupposedthathemeantitliterally。
Hissystemsoftreatmentwerefarinadvanceofhistheoriesregardingthefunctionsoforgans，causesofdisease，etc。，andsomeofthemarestillfirstprincipleswithphysicians。LikeHippocrates，helaidgreatstressoncorrectdiet，exercise，andrelianceuponnature。\"Natureistheoverseerbywhomhealthissuppliedtothesick，\"hesays。\"Naturelendsheraidonallsides，shedecidesandcuresdiseases。Noonecanbesavedunlessnatureconquersthedisease，andnoonediesunlessnaturesuccumbs。\"
FromthepicturethusdrawnofGalenasananatomistandphysician，onemightinferthatheshouldrankveryhighasascientificexponentofmedicine，evenincomparisonwithmodernphysicians。Thereis，however，anothersidetothepicture。Hisknowledgeofanatomywascertainlyveryconsiderable，butmanyofhisdeductionsandtheoriesastothefunctionsoforgans，thecauseofdiseases，andhismethodsoftreatingthem，wouldberecognizedasabsurdbyamodernschool-boyofaverageintelligence。Hisgreatnessmustbejudgedincomparisonwithancient，notwithmodern，scientists。Hemaintained，forexample，thatrespirationandthepulse-beatwereforoneandthesamepurpose——thatofthereceptionofairintothearteriesofthebody。Tohimtheactofbreathingwasforthepurposeofadmittingairintothelungs，whenceitfounditswayintotheheart，andfromtherewasdistributedthroughoutthebodybymeansofthearteries。Theskinalsoplayedanimportantpartinsupplyingthebodywithair，theporesabsorbingtheairanddistributingitthroughthearteries。But，asweknowthathewasawareofthefactthatthearteriesalsocontainedblood，hemusthavebelievedthatthesevesselscontainedamixtureofthetwo。
Modernanatomistsknowthattheheartisdividedintotwoapproximatelyequalpartsbyanimpermeableseptumoftoughfibres。Yet，Galen，whodissectedtheheartsofavastnumberoftheloweranimalsaccordingtohisownaccount，maintainedthatthisseptumwaspermeable，andthattheair，enteringonesideoftheheartfromthelungs，passedthroughitintotheoppositesideandwasthentransferredtothearteries。
Hewasequallyatfault，althoughperhapsmoreexcusablyso，inhisexplanationoftheactionofthenerves。Hehadrightlypointedoutthatnervesweremerelyconnectionsbetweenthebrainandspinal-cordanddistantmusclesandorgans，andhadrecognizedthatthereweretwokindsofnerves，buthisexplanationoftheactionofthesenerveswasthat\"nervousspirits\"werecarriedtothecavitiesofthebrainbyblood-vessels，andfromtheretransmittedthroughthebodyalongthenerve-trunks。
Inthehumanskull，overlyingthenasalcavity，therearetwothinplatesofboneperforatedwithnumeroussmallapertures。
Theseaperturesallowthepassageofnumerousnerve-filamentswhichextendfromagroupofcellsinthebraintothedelicatemembranesinthenasalcavity。Theseperforationsinthebone，therefore，aresimplytoallowthepassageofthenerves。ButGalengaveaverydifferentexplanation。Hebelievedthatimpure\"animalspirits\"werecarriedtothecavitiesofthebrainbythearteriesintheneckandfromthereweresiftedoutthroughtheseperforatedbones，andsoexpelledfromthebody。
Hehadobservedthattheskinplayedanimportantpartincoolingthebody，butheseemstohavebelievedthattheheartwasequallyactiveinoverheatingit。Theskin，therefore，absorbedairforthepurposeof\"coolingtheheart，\"andthiscoolingprocesswasaidedbythebrain，whosesecretionsaidedalsointhecoolingprocess。Theheartitselfwastheseatofcourage；
thebraintheseatoftherationalsoul；andthelivertheseatoflove。
ThegreatnessofGalen’steachingslayinhisknowledgeofanatomyoftheorgans；hisweaknesswasinhisinterpretationsoftheirfunctions。Unfortunately，succeedinggenerationsofphysiciansforsomethinglikeathousandyearsrejectedtheformerbutclungtothelatter，sothattheadvanceshehadmadewerecompletelyovershadowedbythemistakesofhisteachings。
XI。ARETROSPECTIVEGLANCEATCLASSICALSCIENCE
Itisafavoritetenetofthemodernhistorianthathistoryisacontinuousstream。Thecontentionhasfullestwarrant。Sharplinesofdemarcationareanevidenceofman’sanalyticalpropensityratherthantheworkofnature。Neverthelessitwouldbeabsurdtodenythatthestreamofhistorypresentsanever-varyingcurrent。Therearetimeswhenitseemstorushrapidlyon；timeswhenitspreadsoutintoabroad——seeminglystatic——current；timeswhenitscatastrophicchangesremindusofnothingbutagiganticcataract。Rapidsandwhirlpools，broadestuariesandtumultuouscataractsareindeedpartofthesamestream，buttheyarepartsthatvaryonefromanotherintheirsalientfeaturesinsuchawayastoforcethemindtoclassifythemasthingsapartandgivethemindividualnames。
Soitiswiththestreamofhistory；howeverstronglyweinsistonitscontinuitywearenonethelessforcedtorecognizeitsperiodicity。Itmaynotbedesirabletofixonspecificdatesasturning-pointstotheextentthatourpredecessorswerewonttodo。Wemaynot，forexample，bedisposedtoadmitthattheRomanEmpirecametoanysuchcataclysmicfinishastheyear476A。D。，whencitedinconnectionwiththeoverthrowofthelastRomanEmpireoftheWest，mightseemtoindicate。But，ontheotherhand，nostudentoftheperiodcanfailtorealizethatagreatchangecameovertheaspectofthehistoricalstreamtowardsthecloseoftheRomanepoch。
ThespanfromThalestoGalenhascompassedabouteighthundredyears——letussaythirtygenerations。Throughoutthisperiodthereisscarcelyagenerationthathasnotproducedgreatscientificthinkers——menwhohaveputtheirmarkupontheprogressofcivilization；butweshallsee，aswelookforwardforacorrespondingperiod，thattheensuingthirtygenerationsproducedscarcelyasinglescientificthinkerofthefirstrank。
Eighthundredyearsofintellectualactivity——thirtygenerationsofgreatness；theneighthundredyearsofstasis——thirtygenerationsofmediocrity；suchseemstobetherecordasviewedinperspective。Doubtlessitseemedfardifferenttothecontemporaryobserver；itisonlyinreasonableperspectivethatanyscenecanbeviewedfairly。Butforus，lookingbackwithoutprejudiceacrossthestageofyears，itseemsindisputablethatagreatepochcametoacloseataboutthetimewhenthebarbariannationsofEuropebegantosweepdownintoGreeceandItaly。Weareforcedtofeelthatwehavereachedthelimitsofprogressofwhathistoriansarepleasedtocalltheancientworld。ForabouteighthundredyearsGreekthoughthasbeendominant，butintheensuingperioditistoplayaquitesubordinatepart，exceptinsofarasitinfluencesthethoughtofanalienrace。Asweleavethisclassicalepoch，then，wemaywellrecapitulateinbriefitstriumphs。Afewwordswillsufficetosummarizeastorythedetailsofwhichhavemadeupourrecentchapters。
Inthefieldofcosmology，Greekgeniushasdemonstratedthattheearthisspheroidal，thatthemoonisearthlikeinstructureandmuchsmallerthanourglobe，andthatthesunisvastlylargerandmanytimesmoredistantthanthemoon。Theactualsizeoftheearthandtheangleofitsaxiswiththeecliptichavebeenmeasuredwithapproximateaccuracy。Ithasbeenshownthatthesunandmoonpresentinequalitiesofmotionwhichmaybetheoreticallyexplainedbysupposingthattheearthisnotsituatedpreciselyatthecentreoftheirorbits。Asystemofeccentricsandepicycleshasbeenelaboratedwhichservestoexplaintheapparentmotionsoftheheavenlybodiesinamannerthatmaybecalledscientificeventhoughitisbased，aswenowknow，uponafalsehypothesis。Thetruehypothesis，whichplacesthesunatthecentreoftheplanetarysystemandpostulatestheorbitalandaxialmotionsofourearthinexplanationofthemotionsoftheheavenlybodies，hasbeenputforwardandardentlychampioned，but，unfortunately，isnotacceptedbythedominantthinkersatthecloseofourepoch。Inthisregard，therefore，avastrevolutionaryworkremainsforthethinkersofalaterperiod。Moreover，suchobservationsastheprecessionoftheequinoxesandthemoon’sevectionareasyetunexplained，andmeasurementsoftheearth’ssize，andofthesun’ssizeanddistance，aresocrudeandimperfectastobeinonecaseonlyanapproximation，andintheotheranabsurdlyinadequatesuggestion。Butwithallthesedefects，thetotalachievementoftheGreekastronomersisstupendous。TohaveclearlygraspedtheideathattheearthisroundisinitselfanachievementthatmarksofftheclassicalfromtheOrientalperiodasbyagreatgulf。
Inthephysicalscienceswehaveseenatleastthebeginningsofgreatthings。Dynamicsandhydrostaticsmaynow，forthefirsttime，claimaplaceamongthesciences。Geometryhasbeenperfectedandtrigonometryhasmadeasurebeginning。Theconceptionthattherearefourelementarysubstances，earth，water，air，andfire，maynotappearasecurefoundationforchemistry，yetitmarksatleastanattemptintherightdirection。Similarly，theconceptionthatallmatterismadeupofindivisibleparticlesandthatthesehaveadjustedthemselvesandareperhapsheldinplacebyawhirlingmotion，whileitisscarcelymorethanascientificdream，is，afterall，adreamofmarvellousinsight。
Inthefieldofbiologicalscienceprogresshasnotbeensomarked，yettheelaborategarneringoffactsregardinganatomy，physiology，andthezoologicalsciencesisatleastavaluablepreparationforthegeneralizationsofalatertime。
Ifwithamapbeforeusweglanceattheportionoftheglobewhichwasknowntotheworkersoftheperiodnowinquestion，bearinginmindatthesametimewhatwehavelearnedastotheseatoflaborsofthevariousgreatscientificthinkersfromThalestoGalen，wecannotfailtobestruckwitharatherstartlingfact，intimationsofwhichhavebeengivenfromtimetotime——thefact，namely，thatmostofthegreatGreekthinkersdidnotliveinGreeceitself。AsoureyefallsuponAsiaMinoranditsoutlyingislands，wereflectthatherewerebornsuchmenasThales，Anaximander，Anaximenes，Heraclitus，Pythagoras，Anaxagoras，Socrates，Aristarchus，Hipparchus，Eudoxus，Philolaus，andGalen。FromthenorthernshoresoftheaegeancameLucippus，Democritus，andAristotle。Italy，offtothewest，isthehomeofPythagorasandXenophanesintheirlateryears，andofParmenidesandEmpedocles，Zeno，andArchimedes。NorthernAfricacanclaim，bybirthorbyadoption，suchnamesasEuclid，ApolloniusofPerga，Herophilus，Erasistratus，Aristippus，Eratosthenes，Ctesibius，Hero，Strabo，andPtolemy。Thisisbutrunningoverthelistofgreatmenwhosediscoverieshaveclaimedourattention。Werewetoextendthelisttoincludeahostofworkersofthesecondrank，weshouldbutemphasizethesamefact。
AllalongwearespeakingofGreeks，or，astheycallthemselves，Hellenes，andwemeanbythesewordsthepeoplewhosehomewasasmalljaggedpeninsulajuttingintotheMediterraneanatthesoutheasternextremityofEurope。WethinkofthispeninsulaasthehomeofGreekculture，yetofallthegreatthinkerswehavejustnamed，notonewasbornonthispeninsula，andperhapsnotoneinfiveeversetfootuponit。Inpointoffact，oneGreekthinkeroftheveryfirstrank，andoneonly，wasborninGreeceproper；thatone，however，wasPlato，perhapsthegreatestofthemall。Withthisonebrilliantexceptionandevenhewasbornofparentswhocamefromtheprovinces，allthegreatthinkersofGreecehadtheiroriginatthecircumferenceratherthanthecentreoftheempire。AndifwereflectthatthiscircumferenceoftheGreekworldwasinthenatureofthecasethewidelycirclingregioninwhichtheGreekcameincontactwithothernations，weshallseeatoncethattherecouldbenomorestrikingillustrationinallhistorythanthatfurnishedushereofthevalueofracialminglingasastimulustointellectualprogress。
Butthereisoneotherfeatureofthematterthatmustnotbeoverlooked。Racialminglinggivesvitality，buttoproducethebesteffecttheminglingmustbethatofracesallofwhichareatarelativelyhighplaneofcivilization。InAsiaMinortheGreekmingledwiththeSemite，whohadtheheritageofcenturiesofculture；andinItalywiththeUmbrians，Oscans，andEtruscans，who，littleasweknowoftheirantecedents，haveleftusmonumentstotestifytotheirhighdevelopment。ThechiefreasonwhytheracialminglingofalaterdaydidnotavailatoncetogivenewlifetoRomanthoughtwasthattheraceswhichsweptdownfromthenorthwerebarbarians。Itwasnomorepossiblethattheyshouldspringtotheheightsofclassicalculturethanitwould，forexample，bepossibleintwoorthreegenerationstoproducearacerfromastockofdraughthorses。
Evolutiondoesnotproceedbysuchvaultsasthiswouldimply。
Celt，Goth，Hun，andSlavmustundergoprogressivedevelopmentformanygenerationsbeforethepopulationofnorthernEuropecancatchstepwiththeclassicalGreekandpreparetomarchforward。
That，perhaps，isonereasonwhywecometoaperiodofstasisorretrogressionwhenthetimeofclassicalactivityisover。But，atbest，itisonlyonereasonofseveral。
Theinfluenceofthebarbariannationswillclaimfurtherattentionasweproceed。Butnow，forthemoment，wemustturnoureyesintheotherdirectionandgiveattentiontocertainphasesofGreekandofOrientalthoughtwhichweredestinedtoplayamostimportantpartinthedevelopmentoftheWesternmind——amoreimportantpart，indeed，intheearlymediaevalperiodthanthatplayedbythoseimportantinductionsofsciencewhichhavechieflyclaimedourattentioninrecentchapters。Thesubjectinquestionistheoldfamiliaroneoffalseinductionsorpseudoscience。IndealingwiththeearlydevelopmentofthoughtandwithOrientalscience，wehadoccasiontoemphasizethefactthatsuchfalseinductionsledeverywheretotheprevalenceofsuperstition。IndealingwithGreekscience，wehavelargelyignoredthissubject，confiningattentionchieflytotheprogressivephasesofthought；butitmustnotbeinferredfromthisthatGreekscience，withallitssecureinductions，wasentirelyfreefromsuperstition。Onthecontrary，themostcasualacquaintancewithGreekliteraturewouldsufficetoshowtheincorrectnessofsuchasupposition。True，thegreatthinkersofGreecewereprobablyfreerfromthisthraldom。offalseinductionsthananyoftheirpredecessors。EvenataveryearlydaysuchmenasXenophanes，Empedocles，Anaxagoras，andPlatoattainedtoasingularlyrationalisticconceptionoftheuniverse。
Wesawthat\"thefatherofmedicine，\"Hippocrates，banisheddemonologyandconceiveddiseaseasduetonaturalcauses。Ataslightlylaterdaythesophistschallengedallknowledge，andPyrrhonismbecameasynonymforscepticisminrecognitionoftheleadershipofamasterdoubter。TheentireschoolofAlexandriansmusthavebeenrelativelyfreefromsuperstition，elsetheycouldnothavereasonedwithsucheffectivelogicalityfromtheirobservationsofnature。ItisalmostinconceivablethatmenlikeEuclidandArchimedes，andAristarchusandEratosthenes，andHipparchusandHero，couldhavebeenthevictimsofsuchillusionsregardingoccultforcesofnatureaswereconstantlypostulatedbyOrientalscience。HerophilusandErasistratusandGalenwouldhardlyhavepursuedtheiranatomicalstudieswithequanimityhadtheybelievedthatghostlyapparitionswatchedoverlivinganddeadalike，andexercisedatwillamaligninfluence。
DoubtlesstheEgyptianoftheperiodconsideredthework，ofthePtolemaicanatomistsanunspeakableprofanation，and，indeed，itwasnothinglessthanrevolutionary——sorevolutionarythatitcouldnotbesustainedinsubsequentgenerations。WehaveseenthatthegreatGalen，atRome，fivecenturiesafterthetimeofHerophilus，wasprohibitedfromdissectingthehumansubject。ThefactspeaksvolumesfortheattitudeoftheRomanmindtowardsscience。Vastaudiencesmadeupofeverystratumofsocietythrongedtheamphitheatre，andwatchedexultinglywhilemanslewhisfellow-maninsingleorinmultiplecombat。Shoutsoffrenziedjoyburstfromahundredthousandthroatswhenthedeath-strokewasgiventoanewvictim。Thebodiesoftheslain，byscores，evenbyhundreds，weredraggedruthlesslyfromthearenaandhurledintoaditchascontemptuouslyasifpitywereyetunbornandhumanlifethemerestbauble。Yetthesameeyesthatwitnessedthesesceneswithecstaticapprovalwouldhavebeenavertedinpioushorrorhadananatomistdaredtoapproachoneofthemutilatedbodieswiththescalpelofscience。Itwassporttoseethebladeofthegladiatorenterthequivering，livingfleshofhisfellow-gladiator；itwasjoytoseethewarmbloodspurtforthfromthewrithingvictimwhilehestilllived；
butitweresacrilegioustoapproachthatbodywiththeknifeoftheanatomist，onceithadceasedtopulsatewithlife。Lifeitselfwasheldutterlyincontempt，butabouttherealmofdeathhoveredthethreateningghostsofsuperstition。Andsuch，beitunderstood，wastheattitudeoftheRomanpopulaceintheearlyandthemostbrilliantepochoftheempire，beforetheWesternworldcameundertheinfluenceofthatOrientalphilosophywhichwaspresentlytoencompassit。
InthisregardtheAlexandrianworldwas，asjustintimated，farmoreadvancedthantheRoman，yeteventherewemustsupposethattheleadersofthoughtwerewidelyatvariancewiththepopularconceptions。Afewillustrations，drawnfromGreekliteratureatvariousages，willsuggestthepopularattitude。Inthefirstinstance，considerthepoemsofHomerandofHesiod。Forthesewriters，anddoubtlessforthevastmajorityoftheirreaders，notmerelyoftheirownbutofmanysubsequentgenerations，theworldispeopledwithamultitudeofinvisibleapparitions，which，undertitleofgods，areheldtodominatetheaffairsofman。ItissometimesdifficulttodiscriminateastowheretheGreekimaginationdrewthelinebetweenfactandallegory；norneedweattempttoanalysetheearlypoeticnarrativestothisend。Itwillbetterserveourpresentpurposetocitethreeorfourinstanceswhichillustratethetangibilityofbeliefsbaseduponpseudo-scientificinductions。
Letuscite，forexample，theaccountwhichHerodotusgivesusoftheactionsoftheGreeksatPlataea，whentheirarmyconfrontedtheremnantofthearmyofXerxes，intheyear479B。C。Hereweseeeachsidehesitatingtoattacktheother，merelybecausetheoraclehaddeclaredthatwhicheversidestruckthefirstblowwouldlosetheconflict。EvenafterthePersiansoldiers，whoseeminglywereajotlesssuperstitiousorashademoreimpatientthantheiropponents，hadbeguntheattack，wearetoldthattheGreeksdarednotrespondatfirst，thoughtheywerefallingbeforethejavelinsoftheenemy，because，forsooth，theentrailsofafowldidnotpresentanauspiciousappearance。AndthesewereGreeksofthesamegenerationwithEmpedoclesandAnaxagorasandaeschylus；ofthesameepochwithPericlesandSophoclesandEuripidesandPhidias。Suchwasthescientificstatusoftheaveragemind——nay，ofthebestminds——withhereandtherearareexception，inthegoldenageofGrecianculture。
WerewetofollowdownthepagesofGreekhistory，weshouldbutrepeatthesamestoryoverandover。Weshould，forexample，seeAlexandertheGreatbalkedatthebanksoftheHyphasis，andforcedtoturnbackbecauseofinauspiciousauguriesbasedasbeforeuponthedissectionofafowl。Alexanderhimself，tobesure，wouldhavescornedtheaugury；hadhebeenthepreyofsuchpettysuperstitionshewouldneverhaveconqueredAsia。WeknowhowhecompelledtheoracleatDelphitoyieldtohiswishes；howhecuttheGordianknot；howhemadehisdominatingpersonalityfeltatthetempleofAmmoninEgypt。Weknow，inaword，thatheyieldedtosuperstitionsonlyinsofarastheyservedhispurpose。Lefttohisowndevices，hewouldnothaveconsultedanoracleatthebanksoftheHyphasis；or，consulting，wouldhaveforcedfromtheoracleafavorableanswer。Buthissubordinatesweremutinousandhehadnochoice。Sufficeitforourpresentpurposethattheoraclewasconsulted，andthatitsanswerturnedtheconquerorback。
OneortwoinstancesfromRomanhistorymaycompletethepicture。
PassingoverallthosemythicalnarrativeswhichvirtuallyconstitutetheearlyhistoryofRome，aspreservedtousbysuchhistoriansasLivyandDionysius，wefindsologicalanhistorianasTacitusrecordingamiraculousachievementofVespasianwithoutadversecomment。\"DuringthemonthswhenVespasianwaswaitingatAlexandriafortheperiodicalseasonofthesummerwinds，andasafenavigation，manymiraclesoccurredbywhichthefavorofHeavenandasortofbiasinthepowersabovetowardsVespasianweremanifested。\"Tacitusthendescribesindetailthecureofvariousmaladiesbytheemperor，andrelatesthattheemperoronvisitingatemplewasmetthere，inthespirit，byaprominentEgyptianwhowasprovedtobeatthesametimesomeeightymilesdistantfromAlexandria。
ItmustbeadmittedthatTacitus，inrelatingthatVespasiancausedtheblindtoseeandthelametowalk，qualifieshisnarrativebyassertingthat\"personswhoarepresentattestthetruthofthetransactionwhenthereisnothingtobegainedbyfalsehood。\"Normustweoverlookthefactthatasimilarbeliefinthepowerofroyaltyhaspersistedalmosttoourownday。ButnosuchsavorofscepticismattachestoanarrativewhichDionCassiusgivesusofanincidentinthelifeofMarcusAurelius——anincidentthathasbecomefamousastheepisodeofTheThunderingLegion。XiphilinushaspreservedtheaccountofDion，addingcertainpicturesqueinterpretationsofhisown。Theoriginalnarrative，ascited，assertsthatduringoneofthenortherncampaignsofMarcusAurelius，theemperorandhisarmyweresurroundedbythehostileQuadi，whohadeveryadvantageofpositionandwhopresentlyceasedhostilitiesinthehopethatheatandthirstwoulddelivertheiradversariesintotheirhandswithoutthetroubleoffurtherfighting。\"Now，\"saysDion，\"whiletheRomans，unableeithertocombatortoretreat，andreducedtothelastextremitybywounds，fatigue，heat，andthirst，werestandinghelplesslyattheirposts，cloudssuddenlygatheredingreatnumberandraindescendedinfloods——certainlynotwithoutdivineintervention，sincetheEgyptianMaegeArnulphis，whowaswithMarcusAntoninus，issaidtohaveinvokedseveralgeniibytheaerialmercurybyenchantment，andthusthroughthemhadbroughtdownrain。\"
Here，itwillbeobserved，asupernaturalexplanationisgivenofanaturalphenomenon。Butthenarratordoesnotstopwiththis。
IfwearetoaccepttheaccountofXiphilinus，Dionbringsforwardsomestrikingproofsofdivineinterference。Xiphilinusgivestheseproofsinthefollowingremarkableparagraph:
\"Dionaddsthatwhentherainbegantofalleverysoldierliftedhisheadtowardsheaventoreceivethewaterinhismouth；butafterwardsothersholdouttheirshieldsortheirhelmetstocatchthewaterforthemselvesandfortheirhorses。Beingsetuponbythebarbarians……whileoccupiedindrinking，theywouldhavebeenseriouslyincommodedhadnotheavyhailandnumerousthunderboltsthrownconsternationintotheranksoftheenemy。Fireandwaterwereseentomingleastheylefttheheavens。Thefire，however，didnotreachtheRomans，butifitdidbychancetouchoneofthemitwasimmediatelyextinguished，whileatthesametimetherain，insteadofcomfortingthebarbarians，seemedmerelytoexcitelikeoilthefirewithwhichtheywerebeingconsumed。Somebarbariansinflictedwoundsuponthemselvesasthoughtheirbloodhadpowertoextinguishflames，whilemanyrushedovertothesideoftheRomans，hopingthattherewatermightsavethem。\"
WecannotbettercompletetheseillustrationsofpagancredulitythanbyaddingthecommentofXiphilinushimself。ThatwriterwasaChristian，livingsomegenerationslaterthanDion。Heneverthoughtofquestioningthefacts，buthefeltthatDion’sinterpretationofthesefactsmustnotgounchallenged。Asheinterpretsthematter，itwasnopaganmagicianthatwroughtthemiracle。HeeveninclinestothebeliefthatDionhimselfwasawarethatChristianinterference，andnotthatofanEgyptian，savedtheday。\"Dionknew，\"hedeclares，\"thatthereexistedalegioncalledTheThunderingLegion，whichnamewasgivenitfornootherreasonthanforwhatcametopassinthiswar，\"andthatthislegionwascomposedofsoldiersfromMilitenewhowereallprofessedChristians。\"Duringthebattle，\"continuesXiphilinus，\"thechiefofthePretonians，hadsetatMarcusAntoninus，whowasingreatperplexityattheturneventsweretaking，representingtohimthattherewasnothingthepeoplecalledChristianscouldnotobtainbytheirprayers，andthatamonghisforceswasatroopcomposedwhollyoffollowersofthatreligion。
Rejoicedatthisnews，MarcusAntoninusdemandedofthesesoldiersthattheyshouldpraytotheirgod，whograntedtheirpetitionontheinstant，sentlightningamongtheenemyandconsoledtheRomanswithrain。Struckbythiswonderfulsuccess，theemperorhonoredtheChristiansinanedictandnamedtheirlegionTheThundering。ItisevenassertedthataletterexistedbyMarcusAntoninusonthissubject。ThepaganswellknewthatthecompanywascalledTheThunderers，havingattestedthefactthemselves，buttheyrevealednothingoftheoccasiononwhichtheleaderreceivedthename。\"[1]
Peculiarinterestattachestothisnarrativeasillustratingbothcredulousnessastomattersoffactandpseudo-scientificexplanationofallegedfacts。ThemoderninterpretermaysupposethataviolentthunderstormcameupduringthecourseofabattlebetweentheRomansandtheso-calledbarbarians，andthatowingtothelocalcharacterofthestorm，orachancedischargeoflightning，thebarbarianssufferedmorethantheiropponents。Wemaywellquestionwhetherthephilosophicalemperorhimselfputanyotherinterpretationthanthisupontheincident。But，ontheotherhand，weneednotdoubtthatthemajorpartofhissoldierswouldveryreadilyacceptsuchanexplanationasthatgivenbyDionCassius，justasmostreadersofafewcenturieslaterwouldaccepttheexplanationofXiphilinus。Itiswelltobearthisthoughtinmindinconsideringthestaticperiodofscienceuponwhichweareentering。Weshallperhapsbestunderstandthisperiod，anditsseemingretrogressions，ifwesupposethattheaveragemanoftheMiddleAgeswasnomorecredulous，nomoresuperstitious，thantheaverageRomanofanearlierperiodorthantheaverageGreek；thoughtheprecisecomplexionofhiscredulityhadchangedundertheinfluenceofOrientalideas，aswehavejustseenillustratedbythenarrativeofXiphilinus。
APPENDIX
REFERENCELIST，NOTES，ANDBIBLIOGRAPHIES
CHAPTERI。PREHISTORICSCIENCE
LengthofthePrehistoricPeriod——Itisofcoursequiteimpossibletoreducetheprehistoricperiodtoanydefinitenumberofyears。Thereare，however，numerousbitsofevidencethatenableananthropologisttomakeroughestimatesastotherelativelengthsofthedifferentperiodsintowhichprehistorictimeisdivided。GabrieldeMortillet，oneofthemostindustriousstudentsofprehistoricarchaeology，venturedtogiveatentativeestimateastothenumbersofyearsinvolvedineachperiod。Heofcourseclaimedforthisnothingmorethanthevalueofascientificguess。Itis，however，aguessbasedonaverycarefulstudyofalldataatpresentavailable。Mortilletdividestheprehistoricperiod，asawhole，intofourepochs。Thefirstoftheseisthepreglacial，whichheestimatesascomprisingseventy-eightthousandyears；thesecondistheglacial，coveringonehundredthousandyears；thenfollowswhathetermstheSolutreen，whichnumberseleventhousandyears；and，finally，theMagdalenien，comprisingthirty-threethousandyears。Thisgives，fortheprehistoricperiodproper，atermofabouttwohundredandtwenty-twothousandyears。AddtothisperhapstwelvethousandyearsusheringinthecivilizationofEgypt，andthesixthousandyearsofstable，surechronologyofthehistoricalperiod，andwehavesomethingliketwohundredandthirtythousandortwohundredandfortythousandyearsastheageofman。
\"Thesefigures，\"saysMortillet，\"arecertainlynotexaggerated。
Itisevenprobablethattheyarebelowthetruth。Constantlynewdiscoveriesarebeingmadethattendtoremovefartherbackthedateofman’sappearance。\"Wesee，then，accordingtothisestimate，thataboutaquarterofamillionyearshaveelapsedsincemanevolvedtoastatethatcouldproperlybecalledhuman。
Thisguessisasgoodasanother，anditmayadvantageouslybekeptinmind，asitwillenableusallalongtounderstandbetterthanwemightotherwisebeabletodothetremendousforceofcertainprejudicesandpreconceptionswhichrecentmaninheritedfromhisprehistoricancestor。Ideaswhichhadpassedcurrentasunquestionedtruthsforonehundredthousandyearsorsoarenoteasilycastaside。
Ingoingback，inimagination，tothebeginningoftheprehistoricperiod，wemustofcoursereflect，inaccordancewithmodernideasonthesubject，thattherewasnoyear，nomillenniumeven，whenitcouldbesaidexpressly:\"Thisbeingwashithertoaprimate，heisnowaman。\"Thetransitionperiodmusthavebeenenormouslylong，andthechangesfromgenerationtogeneration，evenfromcenturytocentury，musthavebeenveryslight。Inspeakingoftheextentoftheageofmanthismustbeborneinmind:itmustberecalledthat，eveniftheperiodwerenotvagueforotherreasons，thevaguenessofitsbeginningmustmakeitindeterminate。
BibliographicalNotes——Agreatmassofliteraturehasbeenproducedinrecentyearsdealingwithvariousphasesofthehistoryofprehistoricman。Nosingleworkknowntothewriterdealscomprehensivelywiththescientificattainmentsofearlyman；indeed，thesubjectisusuallyignored，exceptwherepracticalphasesofthemechanicalartsareinquestion。Butofcourseanyattempttoconsidertheconditionofprimitivemantaliesintoaccount，byinferenceatleast，hisknowledgeandattainments。Therefore，mostworksonanthropology，ethnology，andprimitiveculturemaybeexpectedtothrowsomelightonourpresentsubject。Worksdealingwiththesocialandmentalconditionsofexistingsavagesarealsoofimportance，sinceitisnowanacceptedbeliefthattheancestorsofcivilizedracesevolvedalongsimilarlinesandpassedthroughcorrespondingstagesofnascentculture。HerbertSpencer’sDescriptiveSociologypresentsanunequalledmassoffactsregardingexistingprimitiveraces，but，unfortunately，itsinartisticmethodofarrangementmakesitrepellenttothegeneralreader。E。B。
Tyler’sPrimitiveCultureandAnthropology；LordAvebury’sPrehistoricTimes，TheOriginofCivilization，andThePrimitiveConditionofMan；W。BoydDawkin’sCave-HuntingandEarlyManinBritain；andEdwardClodd’sChildhoodoftheWorldandStoryofPrimitiveManaredeservedlypopular。PaulTopinard’sElementsd’AnthropologieGeneraleisoneofthebest-knownandmostcomprehensiveFrenchworksonthetechnicalphasesofanthropology；butMortillet’sLePrehistoriquehasamorepopularinterest，owingtoitschaptersonprimitiveindustries，thoughthisworkalsocontainsmuchthatisrathertechnical。Amongperiodicals，theRevuedel’Ecoled’AnthropologiedeParis，publishedbytheprofessors，treatsofallphasesofanthropology，andtheAmericanAnthropologist，editedbyF。W。
HodgefortheAmericanAnthropologicalAssociation，andintendedas\"amediumofcommunicationbetweenstudentsofallbranchesofanthropology，\"containsmuchthatisofinterestfromthepresentstand-point。Thelast-namedjournaldevotesagooddealofspacetoIndianlanguages。
CHAPTERII。EGYPTIANSCIENCE
1p。34。SirJ。NormanLockyer，TheDawnofAstronomy；astudyofthetempleworshipandmythologyoftheancientEgyptians，London，1894。
2p。43。G。Maspero，HistoireAncie-nnedesPeuplesdel’OrientClassique，Paris，1895。Translatedas1TheDawnofCivilization，2TheStruggleoftheNations，3ThePassingoftheEmpires，3vols。，LondonandNewYork，1894-1900。ProfessorMasperoisoneofthemostfamousoflivingOrientalists。HismostimportantspecialstudieshavetodowithEgyptology，buthiswritingscovertheentirefieldofOrientalantiquity。Heisanotablestylist，andhisworksareatoncereadableandauthoritative。
3p。44。AdolfErman，LifeinAncientEgypt，London，1894，p。
352。TranslatedfromtheoriginalGermanworkentitledAegyptenundaegyptischesLebeninAlterthum，Tilbigen，1887。Analtogetheradmirablework，fullofinterestforthegeneralreader，thoughbasedonthemosteruditestudies。
4p。47。Erman，op。cit。，pp。356，357。
5p。48。Erman，op。cit。，p。357。TheworkonEgyptianmedicineherereferredtoisGeorgEbers’editionofanEgyptiandocumentdiscoveredbytheexplorerwhosenameitbears。ItremainsthemostimportantsourceofourknowledgeofEgyptianmedicine。Asmentionedinthetext，thisdocumentdatesfromtheeighteenthdynasty——thatistosay，fromaboutthefifteenthorsixteenthcentury，B。C。，arelativelylateperiodofEgyptianhistory。
6p。49。Erman，op。cit。，p。357。
7p。50。TheHistoryofHerodotus，pp。85-90。Therearenumeroustranslationsofthefamousworkofthe\"fatherofhistory，\"oneofthemostrecentandauthoritativebeingthatofG。C。Macaulay，M。A。，intwovolumes，Macmillan&Co。，LondonandNewYork，1890。
8p。50。TheHistoricalLibraryofDiodorustheSicilian，London，1700。ThismostfamousofancientworldhistoriesisdifficulttoobtaininanEnglishversion。ThemostrecentlypublishedtranslationknowntothewriteristhatofG。Booth，London，1814。
9p。51。Erman，op。cit。，p。357。
10p。52。ThePapyrusRhindisasortofmathematicalhand-bookoftheancientEgyptians；itwasmadeinthetimeoftheHyksosKingsabout2000B。C。，butisacopyofanolderbook。ItisnowpreservedintheBritishMuseum。
ThemostaccessiblerecentsourcesofinformationastothesocialconditionsoftheancientEgyptiansaretheworksofMasperoandErman，abovementioned；andthevariouspublicationsofW。M。FlindersPetrie，ThePyramidsandTemplesofGizeh，London，1883；TanisI。，London，1885；TanisH。，Nebesheh，andDefe-nnel，London，1887；TenYears’Diggings，London，1892；SyriaandEgyptfromtheTel-el-Amar-naLetters，London，1898，etc。ThevariousworksofProfessorPetrie，recordinghisexplorationsfromyeartoyear，givethefullestavailableinsightintoEgyptianarchaeology。
CHAPTERIII。SCIENCEOFBABYLONIAANDASSYRIA
1p。57。TheMedes。Somedifferenceofopinionexistsamonghistoriansastotheexactethnicrelationsoftheconquerors；
theprecisedateofthefallofNinevehisalsoindoubt。
2p。57。Darius。ThefamiliarHebrewnarrativeascribesthefirstPersianconquestofBabylontoDarius，butinscriptionsofCyrusandofNabonidus，theBabylonianking，makeitcertainthatCyruswastherealconqueror。Theseinscriptionsarepreservedoncylindersofbakedclay，ofthetypemadefamiliarbytheexcavationofthepastfiftyyears，andtheyareinvaluablehistoricaldocuments。
3p。58。Berosus。ThefragmentsofBerosushavebeentranslatedbyL。P。Cory，andincludedinhisAncientFragmentsofPhenician，Chaldean，Egyptian，andOtherWriters，London，1826，secondedition，1832。
4p。58。Chaldeanlearning。RecentwritersreservethenameChaldeanforthelaterperiodofBabylonianhistory——thetimewhentheGreekscameincontactwiththeMesopotamians——incontradistinctiontotheearlierperiodswhicharerevealedtousbythearchaeologicalrecords。
5p。59KingSargonofAgade。Thedategivenforthisearlykingmustnotbeacceptedasabsolute；butitisprobablyapproximatelycorrect。
6p。59。Nippur。Seetheaccountoftheearlyexpeditionsasrecordedbythedirector，Dr。JohnP。Peters，Nippur，orexplorationsandadventures，etc。，NewYorkandLondon，1897。
7p。62。FritzHommel，GeschichteBabyloniensundAssyriens，Berlin，1885。
8p。63。R。CampbellThompson，ReportsoftheMagiciansandAstrologersofNinevehandBabylon，London，1900，p。xix。
9p。64。GeorgeSmith，TheAssyrianCanon，p。21。
10p。64。Thompson，op。cit。，p。xix。
11p。65。Thompson，op。cit。，p。2。
12p。67。Thompson，op。cit。，p。xvi。
13p。68。SextusEmpiricus，authorofAdversusMathematicos，livedabout200A。D。
14p。68。R。CampbellThompson，op。cit。，p。xxiv。
15p。72。RecordsofthePasteditor，SamuelBirch，Vol。
III。，p。139。
16p。72。Ibid。，Vol。V。，p。16。
17p。72。QuotedinRecordsofthePast，Vol。III。，p。143，fromtheTranslationsoftheSocietyofBiblicalArcheology，vol。
II。，p。58。
18p。73。RecordsofthePast，vol。L，p。131。
19p。73。Ibid。，vol。V。，p。171。
20p。74。Ibid。，vol。V。，p。169。
21p。74。JoachimMenant，LaBibliothequeduPalaisdeNinive，Paris，188o。
22p。76。CodeofKhamurabi。Thisfamousinscriptionisonablockofblackdioritenearlyeightfeetinheight。ItwasdiscoveredatSusabytheFrenchexpeditionunderM。deMorgan，inDecember，1902。WequotethetranslationgiveninTheHistorians’HistoryoftheWorld，editedbyHenrySmithWilliams，LondonandNewYork，1904，Vol。I，p。510。
23p。77。TheHistoricalLibraryofDiodorusSiculus，p。519。
24p。82。GeorgeS。Goodspeed，Ph。D。，HistoryoftheBabyloniansandAssyrians，NewYork，1902。
25p。82。GeorgeRawlinson，GreatOrientalMonarchies，secondedition，London，1871，Vol。III。，pp。75ff。
Ofthebooksmentionedabove，thatofHommelisparticularlyfullinreferencetoculturedevelopment；Goodspeed’ssmallvolumegivesanexcellentcondensedaccount；theoriginaldocumentsastranslatedinthevariousvolumesofRecordsofthePastarefullofinterest；andMenant’slittlebookisaltogetheradmirable。
TheworkofexcavationisstillgoingoninoldBabylonia，andnewlydiscoveredtextsaddfromtimetotimetoourknowledge，butA。H。Layard’sNinevehanditsRemainsLondon，1849stillhasimportanceasarecordofthemostimportantearlydiscoveries。ThegeneralhistoriesofAntiquityofDuncker，Lenormant，Maspero，andMeyergivefulltreatmentofBabylonianandAssyriandevelopment。SpecialhistoriesofBabyloniaandAssyria，inadditiontothesenamedabove，areTiele’sBabylonisch-AssyrischeGeschichteZweiTiele，Gotha，1886-1888；
Winckler’sGeschichteBabyloniensundAssyriensBerlin，1885-1888，andRogers’HistoryofBabyloniaandAssyria，NewYorkandLondon，1900，thelastofwhich，however，dealsalmostexclusivelywithpoliticalhistory。Certainphasesofscience，particularlywithreferencetochronologyandcosmology，aretreatedbyEdwardMeyerGeschichtedesAlterthum，Vol。I。，Stuttgart，1884，andbyP。JensenDieKosmologiederBabylonier，Strassburg，1890，butnocomprehensivespecifictreatmentofthesubjectinitsentiretyhasyetbeenattempted。
CHAPTERIV。THEDEVELOPMENTOFTHEALPHABET
1p。87。VicomteE。deRouge，Memoiresurl’OrigineEgyptiennedel’AlphabetPhinicien，Paris，1874。
2p。88。SeethevariouspublicationsofMr。ArthurEvans。
3p。80。AztecandMayawriting。Thesepictographsarestillinthemainundecipherable，andopinionsdifferastotheexactstageofdevelopmentwhichtheyrepresent。
4p。90。E。A。WallaceBudge’sFirstStepsinEgyptian，London，1895，isanexcellentelementaryworkontheEgyptianwriting。
ProfessorErman’sEgyptianGrammar，London，1894，istheworkofperhapstheforemostlivingEgyptologist。
5P。93。ExtantexamplesofBabylonianandAssyrianwritinggiveopportunitytocompareearlierandlatersystems，sothefactofevolutionfromthepictorialtothephoneticsystemrestsonsomethingmorethanmeretheory。
6p。96。FriedrichDelitzsch，AssyrischcLesestuckemitgrammatischenTabellenundvollstdndigemGlossareinfiihrungindieassyrischeundbabylonischeKeilschrift-litteraturbishinaufzuHammurabi，Leipzig，1900。
7p。97。ItdoesnotappearthattheBabyloniansthcmselvesevergaveuptheoldsystemofwriting，solongastheyretainedpoliticalautonomy。
8p。101。SeeIsaacTaylor’sHistoryoftheAlphabet；anAccountoftheoriginandDevelopmentofLetters，newedition，2
vols。，London，1899。
Forfacsimilesofthevariousscripts，seeHenrySmithWilliams’
HistoryoftheArtOfWriting，4vols，NewYorkandLondon，1902-1903。
CHAPTERV。THEBEGINNINGSOFGREEKSCIENCE
1p。III。Anaximander，asrecordedbyPlutarch，vol。VIII。SeeArthurFairbanks’FirstPhilosophersofGreece:anEditionandTranslationoftheRemainingFragmentsofthePre-SocraticPhilosophers，togetherwithaTranslationofthemoreImportantAccountsoftheirOpinionsContainedintheEarlyEpitomcsoftheirWorks，London，1898。ThishighlyscholarlyandextremelyusefulbookcontainstheGreektextaswellastranslations。
CHAPTERVI。THEEARLYGREEKPHILOSOPHERSINITALY
1p。117。GeorgeHenryLewes，ABiographicalHistoryofPhilosophyfromitsOrigininGreecedowntothePresentDay，enlargededition，NewYork，1888，p。17。
2p。121。DiogenesLaertius，TheLivesandOpinionsofEminentPhilosophers，C。D。Yonge’stranslation，London，1853，VIII。，p。
153。
3p。121。Alexander，SuccessionsofPhilosophers。
4p。122。\"Alloveritscentre。\"Presumablythisisintendedtorefertotheentireequatorialregion。
5p。125。Laertius，op。cit。，pp。348-351。
6p。128。ArthurFairbanks，TheFirstPhilosophersofGreeceLondon，1898，pp。67-717。
7p。129。Ibid。，p。838。
8p。130。Ibid。，p。109。
9p。130。HeinrichRitter，TheHistoryofAncientPhilosophy，translatedfromtheGermanbyA。J。W。Morrison，4vols。，London，1838，vol，I。，p。463。
10p。131。Ibid。，p。465。
11p。132。GeorgeHenryLewes，op。cit。，p。81。
12p。135。Fairbanks，op。cit。，p。201。
13p。136。Ibid。，P。234。
14p。137。Ibid。，p。189。
15p。137。Ibid。，P。220。
16p。138。Ibid。，p。189。
17p。138。Ibid。，p。191。
CHAPTERVII。GREEKSCIENCEINTHEEARLYATTICPERIOD
1p。150。TheodorGomperz，GreekThinkers:aHistoryofAncientPhilosophytranslatedfromtheGermanbyLaurieMagnes，NewYork，1901，pp。220，221。
2p。153。Aristotle’sTreatiseonRespiration，ch。ii。
3p。159。Fairbanks’translationofthefragmentsofAnaxagoras，inTheFirstPhilosophersofGreece，pp。239-243。
CHAPTERVIII。POST-SOCRATICSCIENCEATATHENS
1p。180。AlfredWilliamBern，ThePhilosophyofGreeceConsideredinRelationtotheCharacterandHistoryofitsPeople，London，1898，p。186。
2p。183。Aristotle，quotedinWilliamWhewell’sHistoryoftheInductiveSciencessecondedition，London，1847，Vol。II。，p。
161。
CHAPTERIX。GREEKSCIENCEOFTHEALEXANDRIANORHELLENISTIC
PERIOD
1p。195。Tertullian’sApologeticus。
2p。205。WequotethequaintoldtranslationofNorth，printedin1657。
CHAPTERX。SCIENCEOFTHEROMANPERIOD
1p。258。TheGeographyofStrabo，translatedbyH。C。HamiltonandW。Falconer，3vols。，London，1857，Vol。I，pp。19，20。
2p。260。Ibid。，p。154。
3p。263。Ibid。，pp。169，170。
4p。264Ibid。，pp。166，167。
5p。271。K。0。MillerandJohnW。Donaldson，TheHistoryoftheLiteratureofGreece，3vols。，London，Vol。III。，p。268。
6p。276。E。T。Withington，MedicalHistoryfron。，theEarliestTimes，London，1894，p。118。
7p。281。Ibid。
8p。281。JohannHermannBass，HistoryofMedicine，NewYork，1889。
CHAPTERXI。ARETROSPECTIVEGLANCEATCLASSICALSCIENCE
p。298。DionCassius，aspreservedbyXiphilinus。OurextractisquotedfromthetranslationgiveninTheHistorians’HistoryoftheWorldeditedbyHenrySmithWilliams，25vols。，LondonandNewYork，1904，Vol。VI。，p。297ff。
[Forfurtherbibliographicalnotes，thereaderisreferredtotheAppendixofvolumeV。]