On Perception's Role in Aristotle's Epistemology The Harvard community has made this article ...

157 Pages·2015·0.61 MB·English

On Perception's Role in Aristotle’s Epistemology
Citation
Gasser, Marc. 2015. On Perception's Role in Aristotle’s Epistemology. Doctoral dissertation,
Harvard University, Graduate School of Arts & Sciences.
Permanent link
http://nrs.harvard.edu/urn-3:HUL.InstRepos:17467304
Terms of Use
This article was downloaded from Harvard University’s DASH repository, and is made available
under the terms and conditions applicable to Other Posted Material, as set forth at http://
nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA
Share Your Story
The Harvard community has made this article openly available.
Please share how this access benefits you. Submit a story .
Accessibility
On Perception’s Role in Aristotle’s Epistemology
Adissertationpresented
by
MarcGasser
to
TheDepartmentofPhilosophy
inpartialfulfillmentoftherequirements
forthedegreeof
DoctorofPhilosophy
inthesubjectof
Philosophy
HarvardUniversity
Cambridge,Massachusetts
April2015
© 2015MarcGasser
Allrightsreserved.
DissertationAdvisor: ProfessorRussellJones MarcGasser
On Perception’s Role in Aristotle’s Epistemology
Abstract
Aristotlethinksallourknowledgecomesfromperception. Yethedoesn’tsay
muchaboutthesenseinwhichourknowledgemightbebasedonorderivedfrom
thethingsweperceive. Sowhatexactlydoesperceptioncontributetothemore
advancedcognitivestatesthatmakeupourintellectuallives,andhowshouldwe
understandthenatureofitscontribution?
Iarguethatperceptioncontributestothesemoreadvancedstatesbyputting
us in touch with particular things in a way that’s responsive to the universals
governingtheirbehavior: perceptibleparticularspossesscertainfeaturesbecause
theyinstantiatecertainuniversals,andperceptionallowsustodiscriminatethese
featuresandexperiencethemasaction-guidingaspectsofourenvironment. Sofor
instance,apatientmightexhibitfeverishfeaturesbecausesheinstantiatesmalarial
disease,andadoctormightperceivethesefeverishfeaturesandexperiencethem
assolicitingsomecourseofaction—assolicitingthatthepatientbeleeched,say.
Iexplainhowperception,sounderstood,canserveasabasisforthedevelop-
mentofaperceptuallydrivenformofpracticalknowledge(ἐμπειρία);roughly,
theformofknowledgepossessedbyadoctorwhoknowshowtocurearangeof
patientsbutcouldnotexplainwhyorhowhertreatmentswork. Ithenexplain
how such practical knowledge can itself serve as a basis for the theoretically
sophisticatedgraspofuniversalsAristotletakesashiscognitiveideal.
iii
Contents
1 AristotelianEpistemology 1
1.1 Aristotleonunderstanding ....................................... 1
1.2 Aristotle&modernepistemology................................ 12
1.3 Justificationandepistemicpriority ............................... 16
1.4 Understandingandconviction ................................... 23
2 PerceptionAsaStartingPoint 28
2.1 Aristotleonlearning ............................................ 29
2.2 Perceptionasastarting-point .................................... 36
2.3 Perceptionandourepistemicascent .............................. 41
3 PerceptionandInduction 48
3.1 Inductionandscientificunderstanding: interpretivechallenges ..... 50
3.2 TheplaceandroleofAPoB19 ................................... 52
3.3 Theplaceandroleofourepistemicascent ........................ 55
3.4 InductionandepistemicascentinB19 ............................ 58
3.5 Thefirststand: perceptiontocraft-knowledge..................... 66
3.6 Subsequentstands: universalstoνοῦς............................. 73
3.7 Inductionandexplanation ....................................... 77
4 PerceivingUniversals 85
4.1 Perceptionandpsychologicaltheory.............................. 87
4.2 Perceivingandperceivingthat.................................... 91
4.3 Particularanduniversalstates.................................... 94
4.4 Particularperceptionandtheperceptionofuniversals.............100
5 PerceptioninAristotle’sEthics 109
5.1 Ethicsasinexactscience ........................................111
5.2 Perceptionandthecharactervirtues .............................118
5.3 Perceptionandpracticalwisdom ................................126
iv
Preface
Overview
Aristotle often seems to downplay perception’s role in our cognitive life. He
characterizes our capacity to perceive as a capacity we share with all animals,
and which yields a form of knowledge far removed from the sort of scientific
understanding he takes as his cognitive ideal—as he puts it in the Metaphysics,
“to perceive is common to all, and therefore easy, and no mark of wisdom”
(982a11-12). SuchdismissiveremarksmakegoodsenseifweconsiderAristotle
viewsonscientificunderstanding: scientificunderstandingissupposedtoallow
us to demonstrate why certain things must be as they are, and perception, as
Aristotle emphasizes, never tells us why things are a certain way, and never
presentsanythingtousasanecessaryfact. Giventheselimitations,it’snaturalto
thinkthatAristotlemusthaveattributedanysignificantepistemicachievement
to some other, non-perceptual cognitive capacity—perhaps a form of rational
intuition, or at least some capacity related to a distinctively human form of
rationalthought.
YetAristotlealsoseemstoassignperceptionacriticalroleinourlearning. He
oftenclaimsthatallourknowledgeultimatelycomesfromperception—aclaim
which(I’llbearguing) playsakeyroleindistinguishinghisepistemologyfrom
v
recollection theories he sought to dismiss. He also claims that the premises of
scientific demonstrations whose conclusions conflict with perceptual evidence
should be given up. So perception serves both as a basis for the development
of more advanced forms of knowledge, and an authority against which such
knowledgeshouldbeassessed.
It also plays a key role in Aristotle’s own scientific practice. Consider for
instanceAristotle’sdescriptionofbears:1
Thebearisomnivorous. Iteatsfruit,andclimbsuptreesthanksto
itsnimblebody. Italsoeatsvegetables,anditwillbreakupabeehive
to get at the honey. It eats crabs and ants, too, and is carnivorous.
The bear is so powerful it will attack not only deer but also wild
boars,ifitcantakethemunawares,andevenbulls. Aftercomingto
closequarterswithabullthebearliesonitsback,facingtheanimal,
and,whenthebulltriestocharge,itgrabsthebull’shornswithits
front paws, fastens its teeth into its shoulder, and drags it down to
theground. Forashorttimeitcanwalkerectonitshindlegs. All
thefleshiteatsitfirstallowstorot. (HA594b6-16)
Itseemsimplausiblethatsomeonededicatedtosuchcareful,detailedobservations
ofanimallifewouldseektodownplayperception’scontributiontoourlearning.
My aim in this dissertation is to provide an interpretation of perception’s
role in Aristotle’s epistemology. I hope to show that there’s a good way to
reconcilethestrongdistinctionAristotledrawsbetweenperceptionandscientific
understandingwiththethoughtthatperceptionprovidesthebasisforallourmore
1TranslationadaptedfromThompson’s.
vi
advancedcognitivestates. Inbroadoutline,Iarguethatperceptioncontributes
to these more advanced states by putting us in touch with particular things in
a way that’s responsive to the universals governing their behavior: perceptible
particulars possess certain features because they instantiate certain universals,
andperceptionallowsustodiscriminatethesefeaturesandexperiencethemas
action-guiding aspects of our environment. I then explain how perception, so
understood,canserveasabasisforthedevelopmentofaperceptually-drivenform
ofpracticalknowledge(ἐμπειρία),andhowsuchpracticalknowledgecanitself
serve as a basis for the theoretically sophisticated grasp of universals Aristotle
takesashiscognitiveideal.
Ibegin,inchapterone,withanaccountofthesortofscientificunderstanding
thatconstitutesthiscognitiveideal. Scientificunderstanding,forAristotle,isthe
cognitivestatepossessedbysomeonewithanexperttheoreticalgrasponsome
bodyofknowledge. Tounderstandsomedomainscientifically(onthereading
I defend) is to know how to demonstrate the truths belonging to that domain
fromtheirmostbasicexplanatorygrounds,wherethesegroundsareexpressedin
thefirstprinciplespropertothedomaininquestion,andthedemonstrationsthat
proceedfromthempresentedinaregimentedsyllogisticsystem. Iarguethat,inan
Aristoteliancontext,questionsaboutthe“epistemicimport”or“epistemicrole”
ofvariouscognitivestatesshouldbeunderstoodasquestionsabouttherelation
these states bear to such scientific understanding, and not as questions about
the justification or warrant for any of our beliefs. I then show how confusion
abouttheroleandnatureofscientificunderstandinghasledtosomecommon
misinterpretationsofAristotelianepistemology,manyofwhichholdἐπιστήμη
asthesolelocusofepistemicjustification.
vii
InchaptertwoIexamineAristotle’saccountofperceptionasastarting-point
forallourlearning. AristotleexplainsinAPoA18thatwecanonlylearnthings
bydemonstration,induction,andperception. It’sclearfromelsewherethat,of
thesethree,perceptionistheonlysourceofknowledgewhichisn’titselfbased
onsomeknowledgewealreadypossess. Iarguethatperceptionisa“source”of
knowledge,ataminimum,inthesensethatitsuppliesthecontent fromwhich
moreadvancedformsofknowledgearederived. Thisisacommoninterpretation,
but it’s often assumed much too quickly. For many of the texts invoked in
its defense are compatible with a highly deflationary take on perception’s role:
perceptioncanoccasionthedevelopmentofmoreadvancedcognitivestates(and
evenbeasinequanonforthisdevelopment) withouttherebeinganyinteresting
connection between the contents we perceive and those we grasp in the states
perceptionbringsabout. Infact,AristotlewasfamiliarwithaPlatonicviewof
thisverysort. Thefactthathedismissesitisgoodevidencethatheendorseda
morerobustconceptionofourperceptualbeginnings.
How, then, do we develop a state of understanding from these perceptual
beginnings? Aristotletellsusthatwedevelopourunderstandingbyinduction,a
formofcognitivedevelopmenthedescribesinsomedetailatAPoB19andMetA1.
YetAristotle’saccountisnotoriouslydifficulttounderstand,andonthewhole
commentatorshavefoundimplausibletheclaimthatinductionalonewouldallow
us to achieve the sort of theoretical expertise scientific understanding requires.
InchapterthreeIarguethatthisisamistake: there’sgoodsensetobemadeof
Aristotle’saccountofourinductiveprogress,andgoodsensetobemadeofthe
claimthatinductionwouldyieldthekindofunderstandingAristotletakesashis
cognitiveideal. AspartofthisargumentIclarifytherelationperceptionbearsto
viii
themoreadvancedcognitivestatesinvolvedinourinductivelearningprocess,in
particulartherelationshipbetweenperception,memoryandἐμπειρία,andthe
relationshipbetweenἐμπειρίαandscientificunderstanding. Oneupshotisthat
practical knowledge plays a critical role in the development of our theoretical
understanding. Perception is the capacity that makes the development of this
practicalknowledgepossible.
In chapter four I focus more closely on perception’s role in this inductive
learning process, and in particular on Aristotle’s claim that perception is of
universalsdespitehavingparticularobjects—aclaimwhich(Iargue) ismeantto
explain perception’s contribution to our cognitive development. Perception’s
particularityisusuallyunderstoodasaformalrestrictiononthescopeofperceptual
knowledge: perception is a cognitive state we bear towards tokens, while types
are only grasped by more advanced states. On this sort of view, perception is
“ofuniversals”inaverythinsense,insofarasthetokensweperceiveinstantiate
varioustypes(typeswedon’treallygraspperceptually).
Idefendadifferentaccountofperception’sparticularanduniversalaspects.
AsIreadAristotle,thesenseinwhichweperceiveparticularshastodowiththe
manner inwhichperceptionputsusintouchwithitsobjects—perceptionalways
dependsonthepresenceofitsobjects,andnevertellsusaboutanycausal relation
betweenthem. Inperceivingparticularswealsoperceiveuniversals: thethings
weperceivepossesscertainfeaturesbecausetheyinstantiatecertainuniversals,and
perceptionallowsustodiscriminatethesefeaturesandexperiencethemasaction-
guidingaspectsofourenvironment. Iarguethatsuchanaccountmakesgoodsense
oftheroleAristotleascribestoperceptioninhisepistemologicalandpsychological
works, and explains how perception’s universal character contributes to our
ix