AssoonasthesoundofthePeace-cryofmydepartingWifehaddiedaway,IbegantoapproachtheStrangerwiththeintentionoftakinganearerviewandofbiddinghimbeseated:buthisappearancestruckmedumbandmotionlesswithastonishment. WithouttheslightestsymptomsofangularityheeneverthelessvariedeveryinstantwithgraduationsofsizeandbrightnessscarcelypossibleforanyFigurewithinthescopeofmyexperience. ThethoughtflashedacrossmethatImighthavebeforemeaburglarorcut-throat,somemonstrousIrregularIsosceles,who,byfeigningthevoiceofaCircle,hadobtainedadmissionsomehowintothehouse,andwasnowpreparingtostabmewithhisacuteangle. Inasitting-room,theabsenceofFog(andtheseasonhappenedtoberemarkablydry),madeitdifficultformetotrusttoSightRecognition,especiallyattheshortdistanceatwhichIwasstanding. Desperatewithfear,Irushedforwardwithanunceremonious,"Youmustpermitme,Sir—"andfelthim.MyWifewasright. Therewasnotthetraceofanangle,nottheslightestroughnessorinequality:neverinmylifehadImetwithamoreperfectCircle. HeremainedmotionlesswhileIwalkedaroundhim,beginningfromhiseyeandreturningtoitagain. Circularhewasthroughout,aperfectlysatisfactoryCircle;therecouldnotbeadoubeofit. Thenfollowedadialogue,whichIwillendeavourtosetdownasnearasIcanrecollectit,omittingonlysomeofmyprofuseapologies—forIwascoveredwithshameandhumiliationthatI,aSquare,shouldhavebeenguiltyoftheimpertinenceoffeelingaCircle. ItwascommencedbytheStrangerwithsomeimpatienceatthelengthinessofmyintroductoryprocess. Stranger.Haveyoufeltmeenoughbythistime?Areyounotintroducedtomeyet? I.MostillustriousSir,excusemyawkwardness,whicharisesnotfromignoranceoftheusagesofpolitesociety,butfromalittlesurpriseandnervousness,consequentonthissomewhatunexpectedvisit. AndIbeseechyoutorevealmyindiscretiontonoone,andespeciallynottomyWife. ButbeforeyourLordshipentersintofurthercommunications,wouldhedeigntosatisfythecuriosityofonewhowouldgladlyknowwhencehisvisitorcame? Stranger.FromSpace,fromSpace,Sir:whenceelse? I.Pardonme,myLord,butisnotyourLordshipalreadyinSpace,yourLordshipandhishumbleservant,evenatthismoment? Stranger.Pooh!whatdoyouknowofSpace?DefineSpace. I.Space,myLord,isheightandbreadthindefinitelyprolonged. Stranger.Exactly:youseeyoudonotevenknowwhatSpaceis.YouthinkitisofTwoDimensionsonly;butIhavecometoannouncetoyouaThird—height,breadth,andlength. I.YourLordshipispleasedtobemerry.Wealsospeakoflengthandheight,orbreadthandthickness,thusdenotingTwoDimensionsbyfournames. Stranger.ButImeannotonlythreenames,butThreeDimensions. I.WouldyourLordshipindicateorexplaintomeinwhatdirectionistheThirdDimension,unknowntome? Stranger.Icamefromit.Itisupaboveanddownbelow. I.MyLordmeansseeminglythatitisNorthwardandSouthward. Stranger.Imeannothingofthekind.Imeanadirectioninwhichyoucannotlook,becauseyouhavenoeyeinyourside. I.Pardonme,myLord,amoment'sinspectionwillconvinceyourLordshipthatIhaveaperfectlyluminaryatthejunctureofmytwosides. Stranger:Yes:butinordertoseeintoSpaceyououghttohaveaneye,notonyourPerimeter,butonyourside,thatis,onwhatyouwouldprobablycallyourinside;butweinSpacelandshouldcallityourside. I.Aneyeinmyinside!Aneyeinmystomach!YourLordshipjests. Stranger.Iaminnojestinghumour. ItellyouthatIcomefromSpace,or,sinceyouwillnotunderstandwhatSpacemeans,fromtheLandofThreeDimensionswhenceIbutlatelylookeddownuponyourPlanewhichyoucallSpaceforsooth. FromthatpositionofadvantageIdiscernedallthatyouspeakofassolid(bywhichyoumean"enclosedonfoursides"),yourhouses,yourchurches,yourverychestsandsafes,yesevenyourinsidesandstomachs,alllyingopenandexposedtomyview. I.Suchassertionsareeasilymade,myLord. Stranger.Butnoteasilyproved,youmean.ButImeantoprovemine. WhenIdescendedhere,IsawyourfourSons,thePentagons,eachinhisapartment,andyourtwoGrandsonstheHexagons;IsawyouryoungestHexagonremainawhilewithyouandthenretiretohisroom,leavingyouandyourWifealone. IsawyourIsoscelesservants,threeinnumber,inthekitchenatsupper,andthelittlePageinthescullery. ThenIcamehere,andhowdoyouthinkIcame? I.Throughtheroof,Isuppose. Yourroof,asyouknowverywell,hasbeenrecentlyrepaired,andhasnoaperturebywhichevenaWomancouldpenetrate.ItellyouIcomefromSpace. AreyounotconvincedbywhatIhavetoldyouofyourchildrenandhousehold? I.YourLordshipmustbeawarethatsuchfactstouchingthebelongingsofhishumbleservantmightbeeasilyascertainedbyanyoneoftheneighbourhoodpossessingyourLordship'samplemeansofinformation. Stranger.(Tohimself.)WhatmustIdo?Stay;onemoreargumentsuggestsitselftome.WhenyouseeaStraightLine—yourwife,forexample—howmanyDimensionsdoyouattributetoher? I.YourLordshipwouldtreatmeasifIwereoneofthevulgarwho,beingignorantofMathematics,supposethataWomanisreallyaStraightLine,andonlyofOneDimension. No,no,myLord;weSquaresarebetteradvised,andareaswellawareofyourLordshipthataWoman,thoughpopularlycalledaStraightLine,is,reallyandscientifically,averythinParallelogram,possessingTwoDimensions,liketherestofus,viz.,lengthandbreadth(orthickness). Stranger.ButtheveryfactthataLineisvisibleimpliesthatitpossessesyetanotherDimension. I.MyLord,IhavejustacknowledgethataWomanisbroadaswellaslong.Weseeherlength,weinferherbreadth;which,thoughveryslight,iscapableofmeasurement. Stranger.Youdonotunderstandme. ImeanthatwhenyouseeaWoman,youought—besidesinferringherbreadth—toseeherlength,andtoseewhatwecallherheight;althoughthelastDimensionisinfinitesimalinyourcountry. IfaLineweremerelengthwithout"height,"itwouldceasetooccupySpaceandwouldbecomeinvisible.Surelyyoumustrecognizethis? I.ImustindeedconfessthatIdonotintheleastunderstandyourLordship. WhenweinFlatlandseeaLine,weseelengthandbrightness. Ifthebrightnessdisappears,theLineisextinguished,and,asyousay,ceasestooccupySpace. ButamItosupposethatyourLordshipgivesthebrightnessthetitleofaDimension,andthatwhatwecall"bright"youcall"high"? Stranger.No,indeed.By"height"ImeanaDimensionlikeyourlength:only,withyou,"height"isnotsoeasilyperceptible,beingextremelysmall. I.MyLord,yourassertioniseasilyputtothetest. YousayIhaveaThirdDimension,whichyoucall"height." Now,Dimensionimpliesdirectionandmeasurement. Dobutmeasuremy"height,"ormerelyindivatetomethedirectioninwhichmy"height"extends,andIwillbecomeyourconvert. Otherwise,yourLordship'sownunderstandmustholdmeexcused. Stranger.(Tohimself.)Icandoneither.HowshallIconvincehim?Surelyaplainstatementoffactsfollowedbyoculardemonstrationoughttosuffice.—Now,Sir;listentome. YouarelivingonaPlane.WhatyoustyleFlatlandisthevastlevelsurfaceofwhatImaycallafluid,orin,thetopofwhichyouandyourcountrymenmoveabout,withoutrisingaboveorfallingbelowit.IamnotaplaneFigure,butaSolid. YoucallmeaCircle;butinrealityIamnotaCircle,butaninfinitenumberofCircles,ofsizevaryingfromaPointtoaCircleofthirteeninchesindiameter,oneplacedonthetopoftheother. WhenIcutthroughyourplaneasIamnowdoing,Imakeinyourplaneasectionwhichyou,veryrightly,callaCircle. ForevenaSphere—whichismypropernameinmyowncountry—ifhemanifesthimselfatalltoaninhabitantofFlatland—mustneedsmanfesthimselfasaCircle. Doyounotremember—forI,whoseeallthings,discernedlastnightthephantasmalvisionofLinelandwrittenuponyourbrain—doyounotremember,Isay,howwhenyouenteredtherealmofLineland,youwerecompelledtomanifestyourselftotheKing,notasaSquare,butasaLine,becausethatLinearRealmhadnotDimensionsenoughtorepresentthewholeofyou,butonlyasliceorsectionofyou? Inpreciselythesameway,yourcountryofTwoDimensionsisnotspaciousenoughtorepresentme,abeingofThree,butcanonlyexhibitasliceorsectionofme,whichiswhatyoucallaCircle. Thediminishedbrightnessofyoureyeindicatesincredulity. Butnowpreparetoreceiveproofpositiveofthetruthofmyassertions. Youcannotindeedseemorethanoneofmysections,orCircles,atatime;foryouhavenopowertoraiseyoureyeoutoftheplaneofFlatland;butyoucanatleastseethat,asIriseinSpace,somysectionsbecomesmaller. Seenow,Iwillrise;andtheeffectuponyoureyewillbethatmyCirclewillbecomesmallerandsmallertillitdwindlestoapointandfinallyvanishes. Therewasno"rising"thatIcouldsee;buthediminishedandfinallyvanished. IwinkedonceortwicetomakesurethatIwasnotdreaming.Butitwasnodream. Forfromthedepthsofnowherecameforthahollowvoice—closetomyheartitseemed—"AmIquitegone?Areyouconvincednow? Well,nowIwillgraduallyreturntoFlatlandandyoushallseemysectionbecomelargerandlarger." EveryreaderinSpacelandwilleasilyunderstandthatmymysteriousGuestwasspeakingthelanguageoftruthandevenofsimplicity. Buttome,proficientthoughIwasinFlatlandMathematics,itwasbynomeansasimplematter. TheroughdiagramgivenabovewillmakeitcleartoanySpacelandchildthattheSphere,ascendinginthethreepositionsindicatedthere,mustneedshavemanifestedhimselftome,ortoanyFlatlander,asaCircle,atfirstoffullsize,thensmall,andatlastverysmallindeed,approachingtoaPoint. Buttome,althoughIsawthefactsbeforeme,thecauseswereasdarkasever. AllthatIcouldcomprehendwas,thattheCirclehadmadehimselfsmallerandvanished,andthathehadnowre-appearedandwasrapidlymakinghimselflarger. Whenheregainedhisoriginalsize,heheavedadeepsigh;forheperceivedbymysilencethatIhadaltogetherfailedtocomprehendhim. AndindeedIwasnowincliningtothebeliefthathemustbenoCircleatall,butsomeextremelycleverjuggler;orelsethattheoldwives'talesweretrue,andthatafterallthereweresuchpeopleasEnchantersandMagicians. Afteralongpausehemutteredtohimself,"Oneresourcealoneremains,ifIamnottoresorttoaction.ImusttrythemethodofAnalogy." Thenfollwedastilllongersilence,afterwhichhecontinuedourdialogue. Sphere.Tellme,Mr.Mathematician;ifaPointmovesNorthward,andleavesaluminouswake,whatnamewouldyougivetothewake? Sphere.AndastraightLinehashowmanyextremities? Sphere.NowconceivetheNorthwardstraightLinemomvingparalleltoitself,EastandWest,sothateverypointinitleavesbehinditthewakeofastraightLine. WhatnamewillyougivetotheFiguretherebyformed? Wewillsupposethatitmovesthroughadistanceequaltotheoriginalstraightline.—-Whatname,Isay? Sphere.AndhowmanysideshasaSquare?Howmanyangles? I.Foursidesandfourangles. Sphere.Nowstretchyourimaginationalittle,andconceiveaSquareinFlatland,movingparalleltoitselfupward. Sphere.No,notNorthward;upward;outofFlatlandaltogether. IfitmovedNorthward,theSouthernpointsintheSquarewouldhavetomovethroughthepositionspreviouslyoccupiedbytheNorthernpoints.Butthatisnotmymeaning. ImeanthateveryPointinyou—foryouareaSquareandwillservethepurposeofmyillustration—everyPointinyou,thatistosayinwhatyoucallyourinside,istopassupwardsthroughSpaceinsuchawaythatnoPointshallpassthroughthepositionpreviouslyoccupiedbyanyotherPoint;buteachPointshalldescribeastraightLineofitsown. ThisisallinaccordancewithAnalogy;surelyitmustbecleartoyou. Restrainingmyimpatience—forIwasnowunderastrongtemptationtorushblindlyatmyVisitorandtoprecipitatehimintoSpace,oroutofFlatland,anywhere,sothatIcouldgetridofhim—Ireplied:— "AndwhatmaybethenatureoftheFigurewhichIamtoshapeoutbythismotionwhichyouarepleasedtodenotebytheword'upward'?IpresumeitisdescribableinthelanguageofFlatland." Itisallplainandsimple,andinstrictaccordancewithAnalogy—only,bytheway,youmustnotspeakoftheresultasbeingaFigure,butasaSolid.ButIwilldescribeittoyou.OrrathernotI,butAnalogy. WebeganwithasinglePoint,whichofcourse—beingitselfaPoine—hasonlyoneterminalPoint. OnePointproducesaLinewithtwoterminalPoints. OneLineproducesaSquarewithfourterminalPoints. Nowyoucangiveyourselftheanswertoyourownquestion:1,2,4,areevidentlyinGeometricalProgression.Whatisthenextnumber? Sphere.Exactly.TheoneSquareproducesaSomething-which-you-do-not-as-yet-know-a-name-for-but-which-we-call-a-CubewitheightterminalPoints.Nowareyouconvinced? I.AndhasthisCreaturesides,aswellasAnglesorwhatyoucall"terminalPoints"? Sphere.Ofcourse;andallaccordingtoAnalogy.But,bytheway,notwhatyoucallsides,butwhatwecallsides.Youwouldcallthemsolids. I.AndhowmanysolidsorsideswillappertaintothisBeingwhomIamtogeneratebythemotionofmyinsideinan"upward"direction,andwhomyoucallaCube? Sphere.Howcanyouask?Andyouamathematician! Thesideofanythingisalways,ifImaysosay,oneDimensionbehindthething. Consequently,asthereisnoDimensionbehindaPoint,aPointhas0sides;aLine,ifImaysosay,has2sides(forthepointsofaLinemaybecalledbycourtesy,itssides);aSquarehas4sides;0,2,4;whatProgressiondoyoucallthat? Sphere.Andwhatisthenextnumber? Sphere.Exactly.Thenyouseeyouhaveansweredyourownquestion.TheCubewhichyouwillgeneratewillbeboundedbysixsides,thatistosay,sixofyourinsides.Youseeitallnow,eh? "Monster,"Ishrieked,"bethoujuggler,enchanter,dream,ordevil,nomorewillIendurethymockeries.EitherthouorImustperish."AndsayingthesewordsIprecipitatedmyselfuponhim.