第15章

’Nature’means(1)thegenesisofgrowingthings-themeaningwhich

wouldbesuggestedifoneweretopronouncethe’u’inphusislong。

(2)Thatimmanentpartofagrowingthing，fromwhichitsgrowthfirst

proceeds。(3)Thesourcefromwhichtheprimarymovementineach

naturalobjectispresentinitinvirtueofitsownessence。Those

thingsaresaidtogrowwhichderiveincreasefromsomethingelseby

contactandeitherbyorganicunity，orbyorganicadhesionasin

thecaseofembryos。Organicunitydiffersfromcontact；forinthe

lattercasethereneednotbeanythingbesidesthecontact，butin

organicunitiesthereissomethingidenticalinbothparts，which

makesthemgrowtogetherinsteadofmerelytouching，andbeonein

respectofcontinuityandquantity，thoughnotofquality-(4)

’Nature’meanstheprimarymaterialofwhichanynaturalobject

consistsoroutofwhichitismade，whichisrelativelyunshaped

andcannotbechangedfromitsownpotency，ase。g。bronzeissaid

tobethenatureofastatueandofbronzeutensils，andwoodthe

natureofwoodenthings；andsoinallothercases；forwhenaproduct

ismadeoutofthesematerials，thefirstmatterispreserved

throughout。Foritisinthiswaythatpeoplecalltheelementsof

naturalobjectsalsotheirnature，somenamingfire，othersearth，

othersair，otherswater，otherssomethingelseofthesort，and

somenamingmorethanoneofthese，andothersallofthem-(5)

’Nature’meanstheessenceofnaturalobjects，aswiththosewhosay

thenatureistheprimarymodeofcomposition，orasEmpedoclessays:-

Nothingthatishasanature，

Butonlymixingandpartingofthemixed，

Andnatureisbutanamegiventhembymen。

Henceasregardsthethingsthatareorcometobebynature，though

thatfromwhichtheynaturallycometobeorareisalreadypresent，

wesaytheyhavenottheirnatureyet，unlesstheyhavetheirform

orshape。Thatwhichcomprisesbothoftheseexistsbynature，e。g。

theanimalsandtheirparts；andnotonlyisthefirstmatternature

(andthisintwosenses，eitherthefirst，countingfromthething，or

thefirstingeneral；e。g。inthecaseofworksinbronze，bronzeis

firstwithreferencetothem，butingeneralperhapswaterisfirst，

ifallthingsthatcanbemeltedarewater)，butalsotheformor

essence，whichistheendoftheprocessofbecoming-(6)Byan

extensionofmeaningfromthissenseof’nature’everyessencein

generalhascometobecalleda’nature’，becausethenatureofa

thingisonekindofessence。

Fromwhathasbeensaid，then，itisplainthatnatureinthe

primaryandstrictsenseistheessenceofthingswhichhavein

themselves，assuch，asourceofmovement；forthematteriscalled

thenaturebecauseitisqualifiedtoreceivethis，andprocessesof

becomingandgrowingarecallednaturebecausetheyaremovements

proceedingfromthis。Andnatureinthissenseisthesourceofthe

movementofnaturalobjects，beingpresentinthemsomehow，either

potentiallyorincompletereality。

Wecall’necessary’(1)(a)thatwithoutwhich，asacondition，

athingcannotlive；e。g。breathingandfoodarenecessaryforan

animal；foritisincapableofexistingwithoutthese；(b)the

conditionswithoutwhichgoodcannotbeorcometobe，orwithout

whichwecannotgetridorbefreedofevil；e。g。drinkingthe

medicineisnecessaryinorderthatwemaybecuredofdisease，and

aman’ssailingtoAeginaisnecessaryinorderthathemaygethis

money-(2)Thecompulsoryandcompulsion，i。e。thatwhichimpedes

andtendstohinder，contrarytoimpulseandpurpose。Forthe

compulsoryiscallednecessary(whencethenecessaryispainful，as

Evenussays:’Foreverynecessarythingiseverirksome’)，and

compulsionisaformofnecessity，asSophoclessays:’Butforce

necessitatesmetothisact’。Andnecessityisheldtobesomething

thatcannotbepersuaded-andrightly，foritiscontrarytothe

movementwhichaccordswithpurposeandwithreasoning-(3)Wesay

thatthatwhichcannotbeotherwiseisnecessarilyasitis。And

fromthissenseof’necessary’alltheothersaresomehowderived；for

athingissaidtodoorsufferwhatisnecessaryinthesenseof

compulsory，onlywhenitcannotactaccordingtoitsimpulsebecause

ofthecompellingforces-whichimpliesthatnecessityisthat

becauseofwhichathingcannotbeotherwise；andsimilarlyasregards

theconditionsoflifeandofgood；forwhenintheonecasegood，

intheotherlifeandbeing，arenotpossiblewithoutcertain

conditions，thesearenecessary，andthiskindofcauseisasortof

necessity。Again，demonstrationisanecessarythingbecausethe

conclusioncannotbeotherwise，iftherehasbeendemonstrationinthe

unqualifiedsense；andthecausesofthisnecessityarethefirst

premisses，i。e。thefactthatthepropositionsfromwhichthe

syllogismproceedscannotbeotherwise。

Nowsomethingsowetheirnecessitytosomethingotherthan

themselves；othersdonot，butarethemselvesthesourceof

necessityinotherthings。Thereforethenecessaryintheprimary

andstrictsenseisthesimple；forthisdoesnotadmitofmorestates

thanone，sothatitcannotevenbeinonestateandalsoin

another；forifitdiditwouldalreadybeinmorethanone。If，then，

thereareanythingsthatareeternalandunmovable，nothing

compulsoryoragainsttheirnatureattachestothem。

’One’means(1)thatwhichisonebyaccident，(2)thatwhichis

onebyitsownnature。(1)Instancesoftheaccidentallyoneare

’Coriscusandwhatismusical’，and’musicalCoriscus’(foritis

thesamethingtosay’Coriscusandwhatismusical’，and’musical

Coriscus’)，and’whatismusicalandwhatisjust’，and’musical

CoriscusandjustCoriscus’。Forallofthesearecalledonebyvirtue

ofanaccident，’whatisjustandwhatismusical’becausetheyare

accidentsofonesubstance，’whatismusicalandCoriscus’becausethe

oneisanaccidentoftheother；andsimilarlyinasense’musical

Coriscus’isonewith’Coriscus’becauseoneofthepartsofthe

phraseisanaccidentoftheother，i。e。’musical’isanaccidentof

Coriscus；and’musicalCoriscus’isonewith’justCoriscus’because

onepartofeachisanaccidentofoneandthesamesubject。The

caseissimilariftheaccidentispredicatedofagenusorofany

universalname，e。g。ifonesaysthatmanisthesameas’musical

man’；forthisiseitherbecause’musical’isanaccidentofman，

whichisonesubstance，orbecausebothareaccidentsofsome

individual，e。g。Coriscus。Both，however，donotbelongtohimin

thesameway，butonepresumablyasgenusandincludedinhis

substance，theotherasastateoraffectionofthesubstance。

Thethings，then，thatarecalledoneinvirtueofanaccident，

arecalledsointhisway。(2)Ofthingsthatarecalledoneinvirtue

oftheirownnaturesome(a)aresocalledbecausetheyare

continuous，e。g。abundleismadeonebyaband，andpiecesofwood

aremadeonebyglue；andaline，evenifitisbent，iscalledoneif

itiscontinuous，aseachpartofthebodyis，e。g。thelegorthe

arm。Ofthesethemselves，thecontinuousbynaturearemoreonethan

thecontinuousbyart。Athingiscalledcontinuouswhichhasbyits

ownnatureonemovementandcannothaveanyother；andthemovementis

onewhenitisindivisible，anditisindivisibleinrespectof

time。Thosethingsarecontinuousbytheirownnaturewhichareone

notmerelybycontact；forifyouputpiecesofwoodtouchingone

another，youwillnotsaytheseareonepieceofwoodoronebodyor

onecontinuumofanyothersort。Things，then，thatarecontinuous

inanywaycalledone，eveniftheyadmitofbeingbent，andstill

morethosewhichcannotbebent；e。g。theshinorthethighismore

onethantheleg，becausethemovementofthelegneednotbeone。And

thestraightlineismoreonethanthebent；butthatwhichisbent

andhasananglewecallbothoneandnotone，becauseitsmovement

maybeeithersimultaneousornotsimultaneous；butthatofthe

straightlineisalwayssimultaneous，andnopartofitwhichhas

magnituderestswhileanothermoves，asinthebentline。

(b)(i)Thingsarecalledoneinanothersensebecausetheir

substratumdoesnotdifferinkind；itdoesnotdifferinthecase

ofthingswhosekindisindivisibletosense。Thesubstratummeant

iseitherthenearestto，orthefarthestfrom，thefinalstate。

For，onetheonehand，wineissaidtobeoneandwaterissaidto

beone，quaindivisibleinkind；and，ontheotherhand，alljuices，

e。g。oilandwine，aresaidtobeone，andsoareallthingsthat

canbemelted，becausetheultimatesubstratumofallisthesame；for

allofthesearewaterorair。

(ii)Thosethingsalsoarecalledonewhosegenusisonethough

distinguishedbyoppositedifferentiae-thesetooareallcalledone

becausethegenuswhichunderliesthedifferentiaeisone(e。g。horse，

man，anddogformaunity，becauseallareanimals)，andindeedina

waysimilartothatinwhichthematterisone。Thesearesometimes

calledoneinthisway，butsometimesitisthehighergenusthatis

saidtobethesame(iftheyareinfimaespeciesoftheirgenus)-the

genusabovetheproximategenera；e。g。theisoscelesandthe

equilateralareoneandthesamefigurebecausebotharetriangles；

buttheyarenotthesametriangles。

(c)Twothingsarecalledone，whenthedefinitionwhichstates

theessenceofoneisindivisiblefromanotherdefinitionwhich

showsustheother(thoughinitselfeverydefinitionisdivisible)。

Thuseventhatwhichhasincreasedorisdiminishingisone，because

itsdefinitionisone，as，inthecaseofplanefigures，isthe

definitionoftheirform。Ingeneralthosethingsthethoughtofwhose

essenceisindivisible，andcannotseparatethemeitherintimeor

inplaceorindefinition，aremostofallone，andofthese

especiallythosewhicharesubstances。Foringeneralthosethings

thatdonotadmitofdivisionarecalledoneinsofarastheydo

notadmitofit；e。g。iftwothingsareindistinguishablequaman，

theyareonekindofman；ifquaanimal，onekindofanimal；ifqua

magnitude，onekindofmagnitude-Nowmostthingsarecalledone

becausetheyeitherdoorhaveorsufferorarerelatedtosomething

elsethatisone，butthethingsthatareprimarilycalledoneare

thosewhosesubstanceisone，-andoneeitherincontinuityorin

formorindefinition；forwecountasmorethanoneeitherthings

thatarenotcontinuous，orthosewhoseformisnotone，orthose

whosedefinitionisnotone。

Whileinasensewecallanythingoneifitisaquantityand

continuous，inasensewedonotunlessitisawhole，i。e。unless

ithasunityofform；e。g。ifwesawthepartsofashoeput

togetheranyhowweshouldnotcallthemoneallthesame(unless

becauseoftheircontinuity)；wedothisonlyiftheyareputtogether

soastobeashoeandtohavealreadyacertainsingleform。This

iswhythecircleisofalllinesmosttrulyone，becauseitis

wholeandcomplete。

(3)Theessenceofwhatisoneistobesomekindofbeginning

ofnumber；forthefirstmeasureisthebeginning，sincethatbywhich

wefirstknoweachclassisthefirstmeasureoftheclass；theone，

then，isthebeginningoftheknowableregardingeachclass。Butthe

oneisnotthesameinallclasses。Forhereitisaquarter-tone，and

thereitisthevowelortheconsonant；andthereisanotherunitof

weightandanotherofmovement。Buteverywheretheoneis

indivisibleeitherinquantityorinkind。Nowthatwhichis

indivisibleinquantityiscalledaunitifitisnotdivisibleinany

dimensionandiswithoutposition，apointifitisnotdivisiblein

anydimensionandhasposition，alineifitisdivisibleinone

dimension，aplaneifintwo，abodyifdivisibleinquantityin

all——i。e。inthree——dimensions。And，reversingtheorder，thatwhich

isdivisibleintwodimensionsisaplane，thatwhichisdivisible

inonealine，thatwhichisinnowaydivisibleinquantityisa

pointoraunit，-thatwhichhasnotpositionaunit，thatwhichhas

positionapoint。

Again，somethingsareoneinnumber，othersinspecies，othersin

genus，othersbyanalogy；innumberthosewhosematterisone，in

speciesthosewhosedefinitionisone，ingenusthosetowhichthe

samefigureofpredicationapplies，byanalogythosewhicharerelated

asathirdthingistoafourth。Thelatterkindsofunityare

alwaysfoundwhentheformerare；e。g。thingsthatareoneinnumber

arealsooneinspecies，whilethingsthatareoneinspeciesare

notalloneinnumber；butthingsthatareoneinspeciesareall

oneingenus，whilethingsthataresoingenusarenotallonein

speciesbutareallonebyanalogy；whilethingsthatareoneby

analogyarenotalloneingenus。

Evidently’many’willhavemeaningsoppositetothoseof’one’；

somethingsaremanybecausetheyarenotcontinuous，othersbecause

theirmatter-eithertheproximatematterortheultimate-is

divisibleinkind，othersbecausethedefinitionswhichstatetheir

essencearemorethanone。