第11章

presuppose，toguardagainstdialecticalobjections，anyfurther

qualificationswhichmightbeadded。This，then，isthemostcertain

ofallprinciples，sinceitanswerstothedefinitiongivenabove。For

itisimpossibleforanyonetobelievethesamethingtobeandnot

tobe，assomethinkHeraclitussays。Forwhatamansays，hedoesnot

necessarilybelieve；andifitisimpossiblethatcontrary

attributesshouldbelongatthesametimetothesamesubject(the

usualqualificationsmustbepresupposedinthispremisstoo)，and

ifanopinionwhichcontradictsanotheriscontrarytoit，obviously

itisimpossibleforthesamemanatthesametimetobelievethesame

thingtobeandnottobe；forifamanweremistakenonthispointhe

wouldhavecontraryopinionsatthesametime。Itisforthisreason

thatallwhoarecarryingoutademonstrationreduceittothisas

anultimatebelief；forthisisnaturallythestarting-pointeven

foralltheotheraxioms。

Therearesomewho，aswesaid，boththemselvesassertthatit

ispossibleforthesamethingtobeandnottobe，andsaythat

peoplecanjudgethistobethecase。Andamongothersmanywriters

aboutnatureusethislanguage。Butwehavenowpositedthatitis

impossibleforanythingatthesametimetobeandnottobe，andby

thismeanshaveshownthatthisisthemostindisputableofall

principles-Someindeeddemandthateventhisshallbedemonstrated，

butthistheydothroughwantofeducation，fornottoknowofwhat

thingsoneshoulddemanddemonstration，andofwhatoneshouldnot，

argueswantofeducation。Foritisimpossiblethatthereshouldbe

demonstrationofabsolutelyeverything(therewouldbeaninfinite

regress，sothattherewouldstillbenodemonstration)；butif

therearethingsofwhichoneshouldnotdemanddemonstration，these

personscouldnotsaywhatprincipletheymaintaintobemore

self-evidentthanthepresentone。

Wecan，however，demonstratenegativelyeventhatthisviewis

impossible，ifouropponentwillonlysaysomething；andifhesays

nothing，itisabsurdtoseektogiveanaccountofourviewstoone

whocannotgiveanaccountofanything，insofarashecannotdo

so。Forsuchaman，assuch，isfromthestartnobetterthana

vegetable。NownegativedemonstrationIdistinguishfromdemonstration

proper，becauseinademonstrationonemightbethoughttobe

beggingthequestion，butifanotherpersonisresponsibleforthe

assumptionweshallhavenegativeproof，notdemonstration。The

starting-pointforallsuchargumentsisnotthedemandthatour

opponentshallsaythatsomethingeitherisorisnot(forthisone

mightperhapstaketobeabeggingofthequestion)，butthatheshall

saysomethingwhichissignificantbothforhimselfandforanother；

forthisisnecessary，ifhereallyistosayanything。For，ifhe

meansnothing，suchamanwillnotbecapableofreasoning，either

withhimselforwithanother。Butifanyonegrantsthis，

demonstrationwillbepossible；forweshallalreadyhavesomething

definite。Thepersonresponsiblefortheproof，however，isnothewho

demonstratesbuthewholistens；forwhiledisowningreasonhelistens

toreason。Andagainhewhoadmitsthishasadmittedthatsomethingis

trueapartfromdemonstration(sothatnoteverythingwillbe’so

andnotso’)。

Firstthenthisatleastisobviouslytrue，thattheword’be’

or’notbe’hasadefinitemeaning，sothatnoteverythingwillbe’so

andnotso’。Again，if’man’hasonemeaning，letthisbe

’two-footedanimal’；byhavingonemeaningIunderstandthis:-if’man’

means’X’，thenifAisaman’X’willbewhat’beingaman’meansfor

him。(Itmakesnodifferenceevenifoneweretosayawordhas

severalmeanings，ifonlytheyarelimitedinnumber；fortoeach

definitiontheremightbeassignedadifferentword。Forinstance，

wemightsaythat’man’hasnotonemeaningbutseveral，oneof

whichwouldhaveonedefinition，viz。’two-footedanimal’，whilethere

mightbealsoseveralotherdefinitionsifonlytheywerelimitedin

number；forapeculiarnamemightbeassignedtoeachofthe

definitions。If，however，theywerenotlimitedbutoneweretosay

thatthewordhasaninfinitenumberofmeanings，obviously

reasoningwouldbeimpossible；fornottohaveonemeaningisto

havenomeaning，andifwordshavenomeaningourreasoningwithone

another，andindeedwithourselves，hasbeenannihilated；foritis

impossibletothinkofanythingifwedonotthinkofonething；but

ifthisispossible，onenamemightbeassignedtothisthing。)

Letitbeassumedthen，aswassaidatthebeginning，thatthe

namehasameaningandhasonemeaning；itisimpossible，then，that

’beingaman’shouldmeanprecisely’notbeingaman’，if’man’not

onlysignifiessomethingaboutonesubjectbutalsohasone

significance(forwedonotidentify’havingonesignificance’with

’signifyingsomethingaboutonesubject’，sinceonthatassumption

even’musical’and’white’and’man’wouldhavehadone

significance，sothatallthingswouldhavebeenone；fortheywould

allhavehadthesamesignificance)。

Anditwillnotbepossibletobeandnottobethesamething，

exceptinvirtueofanambiguity，justasifonewhomwecall’man’，

othersweretocall’not-man’；butthepointinquestionisnot

this，whetherthesamethingcanatthesametimebeandnotbea

maninname，butwhetheritcaninfact。Nowif’man’and’not-man’

meannothingdifferent，obviously’notbeingaman’willmean

nothingdifferentfrom’beingaman’；sothat’beingaman’willbe

’notbeingaman’；fortheywillbeone。Forbeingonemeans

this-beingrelatedas’raiment’and’dress’are，iftheirdefinition

isone。Andif’beingaman’and’beinganot-man’aretobeone，they

mustmeanonething。Butitwasshownearlier’thattheymean

differentthings-Therefore，ifitistruetosayofanythingthat

itisaman，itmustbeatwo-footedanimal(forthiswaswhat’man’

meant)；andifthisisnecessary，itisimpossiblethatthesamething

shouldnotatthattimebeatwo-footedanimal；forthisiswhat

’beingnecessary’means-thatitisimpossibleforthethingnottobe。

Itis，then，impossiblethatitshouldbeatthesametimetruetosay

thesamethingisamanandisnotaman。

Thesameaccountholdsgoodwithregardto’notbeingaman’，

for’beingaman’and’beinganot-man’meandifferentthings，since

even’beingwhite’and’beingaman’aredifferent；fortheformer

termsaremuchmoredifferentsothattheymustafortiorimean

differentthings。Andifanyonesaysthat’white’meansoneandthe

samethingas’man’，againweshallsaythesameaswhatwassaid

before，thatitwouldfollowthatallthingsareone，andnotonly

opposites。Butifthisisimpossible，thenwhatwehavemaintained

willfollow，ifouropponentwillonlyanswerourquestion。

Andif，whenoneasksthequestionsimply，headdsthe

contradictories，heisnotansweringthequestion。Forthereis

nothingtopreventthesamethingfrombeingbothamanandwhite

andcountlessotherthings:butstill，ifoneaskswhetheritisoris

nottruetosaythatthisisaman，ouropponentmustgiveananswer

whichmeansonething，andnotaddthat’itisalsowhiteand

large’。For，besidesotherreasons，itisimpossibletoenumerate

itsaccidentalattributes，whichareinfiniteinnumber；lethim，

then，enumerateeitherallornone。Similarly，therefore，evenif

thesamethingisathousandtimesamanandanot-man，hemustnot，

inansweringthequestionwhetherthisisaman，addthatitisalso

atthesametimeanot-man，unlessheisboundtoaddalsoallthe

otheraccidents，allthatthesubjectisorisnot；andifhedoes

this，heisnotobservingtherulesofargument。

Andingeneralthosewhosaythisdoawaywithsubstanceand

essence。Fortheymustsaythatallattributesareaccidents，andthat

thereisnosuchthingas’beingessentiallyaman’or’ananimal’。

Forifthereistobeanysuchthingas’beingessentiallyaman’this

willnotbe’beinganot-man’or’notbeingaman’(yettheseare

negationsofit)；fortherewasonethingwhichitmeant，andthiswas

thesubstanceofsomething。Anddenotingthesubstanceofathing

meansthattheessenceofthethingisnothingelse。Butifits

beingessentiallyamanistobethesameaseitherbeing

essentiallyanot-manoressentiallynotbeingaman，thenitsessence

willbesomethingelse。Thereforeouropponentsmustsaythatthere

cannotbesuchadefinitionofanything，butthatallattributesare

accidental；forthisisthedistinctionbetweensubstanceand

accident-’white’isaccidentaltoman，becausethoughheiswhite，

whitenessisnothisessence。Butifallstatementsareaccidental，

therewillbenothingprimaryaboutwhichtheyaremade，ifthe

accidentalalwaysimpliespredicationaboutasubject。The

predication，then，mustgoonadinfinitum。Butthisisimpossible；

fornotevenmorethantwotermscanbecombinedinaccidental

predication。For(1)anaccidentisnotanaccidentofanaccident，

unlessitbebecausebothareaccidentsofthesamesubject。Imean，

forinstance，thatthewhiteismusicalandthelatteriswhite，

onlybecausebothareaccidentaltoman。But(2)Socratesis

musical，notinthissense，thatbothtermsareaccidentalto

somethingelse。Sincethensomepredicatesareaccidentalinthis

andsomeinthatsense，(a)thosewhichareaccidentalinthelatter

sense，inwhichwhiteisaccidentaltoSocrates，cannotforman

infiniteseriesintheupwarddirection；e。g。Socratesthewhitehas

notyetanotheraccident；fornounitycanbegotoutofsuchasum。

Noragain(b)will’white’haveanothertermaccidentaltoit，e。g。

’musical’。Forthisisnomoreaccidentaltothatthanthatisto

this；andatthesametimewehavedrawnthedistinction，thatwhile

somepredicatesareaccidentalinthissense，othersaresointhe

senseinwhich’musical’isaccidentaltoSocrates；andtheaccident

isanaccidentofanaccidentnotincasesofthelatterkind，but

onlyincasesoftheotherkind，sothatnotalltermswillbe

accidental。Theremust，then，evensobesomethingwhichdenotes

substance。Andifthisisso，ithasbeenshownthatcontradictories

cannotbepredicatedatthesametime。

Again，ifallcontradictorystatementsaretrueofthesame

subjectatthesametime，evidentlyallthingswillbeone。Forthe

samethingwillbeatrireme，awall，andaman，ifofeverythingit

ispossibleeithertoaffirmortodenyanything(andthispremiss

mustbeacceptedbythosewhosharetheviewsofProtagoras)。Forif

anyonethinksthatthemanisnotatrireme，evidentlyheisnota

trireme；sothathealsoisatrireme，if，astheysay，

contradictorystatementsarebothtrue。Andwethusgetthedoctrine

ofAnaxagoras，thatallthingsaremixedtogether；sothatnothing

reallyexists。Theyseem，then，tobespeakingoftheindeterminate，

and，whilefancyingthemselvestobespeakingofbeing，theyare

speakingaboutnon-being；foritisthatwhichexistspotentially

andnotincompleterealitythatisindeterminate。Buttheymust

predicateofeverysubjecttheaffirmationorthenegationofevery

attribute。Foritisabsurdifofeachsubjectitsownnegationis

tobepredicable，whilethenegationofsomethingelsewhichcannotbe

predicatedofitisnottobepredicableofit；forinstance，ifitis

truetosayofamanthatheisnotaman，evidentlyitisalsotrue

tosaythatheiseitheratriremeornotatrireme。If，then，the

affirmativecanbepredicated，thenegativemustbepredicabletoo；

andiftheaffirmativeisnotpredicable，thenegative，atleast，will

bemorepredicablethanthenegativeofthesubjectitself。If，

then，eventhelatternegativeispredicable，thenegativeof

’trireme’willbealsopredicable；and，ifthisispredicable，the

affirmativewillbesotoo。