ScepticismScepticism

ScepticismScepticism

Beliefs (in a certain area) areBeliefs (in a certain area) are Unjustified Unjustified ((targettarget: internalism): internalism) Unreliable Unreliable ((targettarget: externalism): externalism)

So, (a certain kind of) knowledge is So, (a certain kind of) knowledge is impossibleimpossible

Extreme form: all beliefs are unjustified or Extreme form: all beliefs are unjustified or unreliable; all knowledge is impossibleunreliable; all knowledge is impossible

Thesis and RecommendationThesis and Recommendation

Thesis: Knowledge (of a certain kind) is Thesis: Knowledge (of a certain kind) is impossibleimpossible

Recommendation: So, one ought to _____.Recommendation: So, one ought to _____. Problem: How can the extreme skeptic get Problem: How can the extreme skeptic get

from the thesis to the recommendation?from the thesis to the recommendation? It seems that it requires an inferenceIt seems that it requires an inference Extreme skepticism undercuts such Extreme skepticism undercuts such

inferencesinferences

Daoism: Zhuangzi (c. -350)Daoism: Zhuangzi (c. -350)

Intellectual distinctions Intellectual distinctions correspond to nothing correspond to nothing in realityin reality

There’s no point to There’s no point to doing anythingdoing anything

Zhu Xi: “Laozi still Zhu Xi: “Laozi still wanted to do wanted to do something, but something, but Zhuangzi didn’t want to Zhuangzi didn’t want to do anything at all.”do anything at all.”

Identity of ContrariesIdentity of Contraries

Can we be completely objective?Can we be completely objective? No— the objective and subjective are No— the objective and subjective are

intertwinedintertwined Objective —> subjective: you can reach Objective —> subjective: you can reach

objective knowledge only by depending on objective knowledge only by depending on your own subjective mental statesyour own subjective mental states

Subjective —> objective: your being in a Subjective —> objective: your being in a mental state depends on and gives rise to mental state depends on and gives rise to objective facts about youobjective facts about you

Three in the MorningThree in the Morning

““A keeper of monkeys said with regard to their A keeper of monkeys said with regard to their rations of chestnuts that each monkey was to have rations of chestnuts that each monkey was to have three in the morning and four at night. But at this three in the morning and four at night. But at this the monkeys were very angry, so the keeper said the monkeys were very angry, so the keeper said they might have four in the morning and three at they might have four in the morning and three at night, with which arrangement they were all well night, with which arrangement they were all well pleased. The actual number of the chestnuts pleased. The actual number of the chestnuts remained the same, but there was an adaptation remained the same, but there was an adaptation to the likes and dislikes of those concerned. Such to the likes and dislikes of those concerned. Such is the principle of putting oneself into subjective is the principle of putting oneself into subjective relation with externals.”relation with externals.”

Identity of All ThingsIdentity of All Things

We draw distinctionsWe draw distinctions But things aren’t distinct in the worldBut things aren’t distinct in the world Everything is Everything is DaoDao Everything is in the eye of the beholderEverything is in the eye of the beholder There is no objectivityThere is no objectivity There is no knowledgeThere is no knowledge

VariabilityVariability

VariabilityVariability: Things are perceived differently : Things are perceived differently by different beings at different timesby different beings at different times

UndecidabilityUndecidability: There is no neutral way to : There is no neutral way to determine which perceptions are trustworthydetermine which perceptions are trustworthy

Sceptical thesisSceptical thesis: Therefore, knowledge is : Therefore, knowledge is impossibleimpossible

Problem of the CriterionProblem of the Criterion

UndecidabilityUndecidability: There is no neutral way to : There is no neutral way to tell which perceptions ought to be trustedtell which perceptions ought to be trusted

We need a criterion for determining thisWe need a criterion for determining this

But where could we get it? Even if we could But where could we get it? Even if we could get one, we couldn’t justify itget one, we couldn’t justify it

Possibility of DreamingPossibility of Dreaming

““Those who dream of the banquet, wake to Those who dream of the banquet, wake to lamentation and sorrow. Those who dream lamentation and sorrow. Those who dream of lamentation and sorrow wake to join the of lamentation and sorrow wake to join the hunt. While they dream, they do not know hunt. While they dream, they do not know that they dream. Some will even interpret that they dream. Some will even interpret the very dream they are dreaming: and only the very dream they are dreaming: and only when they awake do they know it was a when they awake do they know it was a dream.”dream.”

Possibility of DreamingPossibility of Dreaming

““Once upon a time, I, Zhuangzi, dreamt I Once upon a time, I, Zhuangzi, dreamt I was a butterfly, fluttering hither and thither, was a butterfly, fluttering hither and thither, to all intents and purposes a butterfly. I was to all intents and purposes a butterfly. I was conscious only of following my fancies as a conscious only of following my fancies as a butterfly, and was unconscious of my butterfly, and was unconscious of my individuality as a man. Suddenly, I awaked, individuality as a man. Suddenly, I awaked, and there I lay, myself again. Now I do not and there I lay, myself again. Now I do not know whether I was then a man dreaming I know whether I was then a man dreaming I was a butterfly, or whether I am now a was a butterfly, or whether I am now a butterfly, dreaming I am a man.”butterfly, dreaming I am a man.”

Zhuangzi’s RecommendationZhuangzi’s Recommendation

““The true sage rejects all distinctions of this The true sage rejects all distinctions of this and that. He takes his refuge in and that. He takes his refuge in DaoDao and and places himself in subjective relation with all places himself in subjective relation with all things.”things.”

But how can he justify his recommendation?But how can he justify his recommendation? Does it follow from his thesis?Does it follow from his thesis? Does he know it?Does he know it?

Philo of Alexandria (-20 - 40)Philo of Alexandria (-20 - 40)

First to attempt project First to attempt project of reconciling Jewish of reconciling Jewish scriptures with Greek scriptures with Greek philosophyphilosophy

Tries to construct Tries to construct sceptical arguments sceptical arguments without metaphysical without metaphysical presuppositions in “On presuppositions in “On Drunkenness”Drunkenness”

VariabilityVariability

Variation in perception Variation in perception among different among different species, different species, different people, even same people, even same person on different person on different occasionsoccasions

How do we know How do we know which portray reality which portray reality accurately?accurately?

Argument from IllusionArgument from Illusion

We often misperceive thingsWe often misperceive things

There is no way to tell when There is no way to tell when we’re misperceiving thingswe’re misperceiving things

So, on any given occasion, So, on any given occasion, we might be misperceiving we might be misperceiving thingsthings

ComparisonComparison

We know, not things in We know, not things in themselves, but things themselves, but things in relation to other in relation to other things— including usthings— including us

We know things only We know things only as they relate to usas they relate to us

We can’t distinguish We can’t distinguish what’s really in the what’s really in the object from what we object from what we are contributingare contributing

Zeno’s ParadoxesZeno’s Paradoxes

Arguments against Arguments against possibility of motionpossibility of motion

Runner: one must first Runner: one must first go halfway. . . .go halfway. . . .

Achilles and the Achilles and the Tortoise: The tortoise Tortoise: The tortoise gets a head start; gets a head start; Achilles must first get Achilles must first get to its starting point, but to its starting point, but by then it has moved by then it has moved onon

Sextus Empiricus (c. 200)Sextus Empiricus (c. 200)

We can’t tell what’s in We can’t tell what’s in the object and what we the object and what we contributecontribute

Knowledge of “external Knowledge of “external underlying objects” is underlying objects” is impossibleimpossible

Recommendation: Recommendation: suspend judgmentsuspend judgment

Problem of the Criterion, 2Problem of the Criterion, 2

Is there a criterion of Is there a criterion of truth?truth?

To settle this, we need To settle this, we need a criteriona criterion

But that’s what’s at But that’s what’s at issue!issue!

Dogmatist must argue Dogmatist must argue in a circle,in a circle,

Or face infinite regressOr face infinite regress

Suspension & Suspension & AtaraxiaAtaraxia

Suspension of Suspension of judgment —> peace of judgment —> peace of mind (mind (ataraxiaataraxia))

But the sceptic can’t But the sceptic can’t know this, or even know this, or even assert itassert it

It just happensIt just happens

Peace of MindPeace of Mind

““The Skeptic, in fact, had the same experience which is The Skeptic, in fact, had the same experience which is said to have befallen the painter Apelles. Once, they say, said to have befallen the painter Apelles. Once, they say, when he was painting a horse and wished to represent in when he was painting a horse and wished to represent in the painting the horses foam, he was so unsuccessful that the painting the horses foam, he was so unsuccessful that he gave up the attempt and flung at the picture the sponge he gave up the attempt and flung at the picture the sponge on which he used to wipe the paints off his brush, and the on which he used to wipe the paints off his brush, and the mar of the sponge produced the effect of a horse’s foam. mar of the sponge produced the effect of a horse’s foam. So, too, the Skeptics were in hopes of gaining quietude by So, too, the Skeptics were in hopes of gaining quietude by means of a decision regarding the disparity of the objects means of a decision regarding the disparity of the objects of sense and of thought, and being unable to effect this of sense and of thought, and being unable to effect this they suspended judgment; and they found that quietude, as they suspended judgment; and they found that quietude, as if by chance, followed upon their suspense, even as a if by chance, followed upon their suspense, even as a shadow follows its substance.”shadow follows its substance.”

Nagarjuna (c. 1000)Nagarjuna (c. 1000)

Mahayana Buddhist, 14th Mahayana Buddhist, 14th Indian Zen patriarchIndian Zen patriarch

Founder of Madhyamika Founder of Madhyamika BuddhismBuddhism

Destroy theorizingDestroy theorizing Leave ordinary life alone: Leave ordinary life alone:

“For we do not speak without “For we do not speak without accepting, for practical accepting, for practical purposes, the work-a-day purposes, the work-a-day world”world”

Attack on Attack on pramanaspramanas

I know something I know something because it arises from a because it arises from a reliable source of reliable source of knowledgeknowledge

But how do I know that But how do I know that source of knowledge is source of knowledge is reliable?reliable?

Need a Need a pramanapramana of of pramanaspramanas, etc.— infinite , etc.— infinite regressregress

Nagarjuna’s Regress ArgumentNagarjuna’s Regress Argument

““And if, for you, there is a source [of And if, for you, there is a source [of knowledge] of each and every object of knowledge] of each and every object of proof,proof,Then tell how, in turn, for you there is proof Then tell how, in turn, for you there is proof of those sources.of those sources.If by other sources [of knowledge] there If by other sources [of knowledge] there would be the proof of a source-- that would would be the proof of a source-- that would be an ‘infinite regress’;be an ‘infinite regress’;in that case neither a beginning, middle, or in that case neither a beginning, middle, or and end is proved.”and end is proved.”

PramanaPramana of of pramanaspramanas

Sources of knowledge: Sources of knowledge: perception, analogy, perception, analogy, testimony, inferencetestimony, inference

Knowledge is justified only Knowledge is justified only if we know we’re using the if we know we’re using the appropriate sourceappropriate source

What could be source of What could be source of knowledge for that?knowledge for that?

QuietismQuietism

If knowledge is impossible, If knowledge is impossible, how can we know the truth how can we know the truth of scepticism?of scepticism?

Isn’t scepticism unreliable Isn’t scepticism unreliable or unjustified?or unjustified?

““If I would make any If I would make any proposition whatever, then proposition whatever, then by that I would have a by that I would have a logical error; But I do not logical error; But I do not make a proposition, make a proposition, therefore I am not in error.”therefore I am not in error.”

NyayaNyaya Response Response

We don’t need a We don’t need a pramanapramana for for pramanaspramanas

Means of knowledge Means of knowledge ((pramanaspramanas) and objects of ) and objects of knowledge (knowledge (prameyasprameyas) support ) support each othereach other

Sutra 16:Sutra 16: Just as the Just as the 'measuring instrument' (which 'measuring instrument' (which usually has the status of a usually has the status of a pramanapramana) can be a ) can be a prameyaprameya as as well (i.e. when its own accuracy well (i.e. when its own accuracy is subject to investigation).is subject to investigation).

ScalesScales

Analogy: scalesAnalogy: scales How do we test the How do we test the

reliability of a scale?reliability of a scale? We compare weights it We compare weights it

gives for objects with gives for objects with known weights by known weights by other scalesother scales

We don’t need a “scale We don’t need a “scale of scales”of scales”

NyayaNyaya Coherentism Coherentism

No foundation, no No foundation, no givengiven

One thing may be One thing may be justifier or justified, justifier or justified, depending on depending on circumstancescircumstances

Epistemic role Epistemic role depends on contextdepends on context

LuminosityLuminosity

Sutra 19Sutra 19: . . . these : . . . these (i.e. perception etc.) (i.e. perception etc.) are apprehended in are apprehended in the same way as the the same way as the light of a lamp.light of a lamp.

Light can be both Light can be both means of seeing and means of seeing and the thing seenthe thing seen

Gangesa (c. 1350)Gangesa (c. 1350)

Local doubt (e.g., Local doubt (e.g., eyes, scale): we doubt eyes, scale): we doubt when something when something anomalous happens, anomalous happens, and resolve as in the and resolve as in the NyayaNyaya--sutrasutra

Global doubt: we have Global doubt: we have no reason to entertain; no reason to entertain; makes no sense to say makes no sense to say everything is anomalyeverything is anomaly

Pragmatic InconsistencyPragmatic Inconsistency

““Thus it has been said (by Thus it has been said (by Udayana): "That is doubted Udayana): "That is doubted concerning which as doubted concerning which as doubted there occurs no contradiction there occurs no contradiction with the doubter's action." For it with the doubter's action." For it is not possible at once to resort is not possible at once to resort regularly to fire and the like for regularly to fire and the like for smoke and the like and to doubt smoke and the like and to doubt that fire causes it (it would be that fire causes it (it would be meaningless behavior). This is meaningless behavior). This is how we should understand how we should understand Udayana's saying. . . . It is the Udayana's saying. . . . It is the doubter's own behavior that doubter's own behavior that proves the lie to the doubt, i.e., proves the lie to the doubt, i.e., that blocks it.”that blocks it.”

Augustine (354-430)Augustine (354-430)

Logical and mathematical truths Logical and mathematical truths can be known, even if sceptical can be known, even if sceptical arguments succeedarguments succeed

““I am certain that either there is I am certain that either there is only one world or there are more only one world or there are more worlds than one. I am likewise worlds than one. I am likewise certain that if there are more certain that if there are more worlds than one, their number is worlds than one, their number is either finite or infinite.”either finite or infinite.”

Augustine: PerceptionAugustine: Perception

““In fact, I believe that the In fact, I believe that the senses are not untrustworthy senses are not untrustworthy either because deranged either because deranged persons suffer illusions, or persons suffer illusions, or because we see things because we see things wrongly when we are asleep. If wrongly when we are asleep. If the senses correctly intimate the senses correctly intimate things to the vigilant and the things to the vigilant and the sane, it is no affair of theirs sane, it is no affair of theirs what the mind of a sleeping or what the mind of a sleeping or insane person may fancy for insane person may fancy for itself.”itself.”

Augustine: AppearancesAugustine: Appearances

““Restrict your assent to the mere Restrict your assent to the mere fact of your being convinced that it fact of your being convinced that it appears thus to you. Then there is appears thus to you. Then there is no deception, for I do not see how no deception, for I do not see how even an Academic [Skeptic] can even an Academic [Skeptic] can refute a man who says: ‘I know that refute a man who says: ‘I know that this appears white to me. I know this appears white to me. I know that I am delighted by what I am that I am delighted by what I am hearing. I know that this smells hearing. I know that this smells pleasant to me. I know that this pleasant to me. I know that this tastes sweet to me. I know that this tastes sweet to me. I know that this feels cold to me.’”feels cold to me.’”

Self-knowledgeSelf-knowledge ““I am most certain that I am, and I am most certain that I am, and

that I know and delight in this. In that I know and delight in this. In respect of these truths, I am not respect of these truths, I am not at all afraid of the arguments of at all afraid of the arguments of the Academicians, who say, the Academicians, who say, What if you are deceived? For if What if you are deceived? For if I am deceived, I am. . . . I am deceived, I am. . . . [C]ertainly I am not deceived in [C]ertainly I am not deceived in this knowledge that I am. And, this knowledge that I am. And, consequently, neither am I consequently, neither am I deceived in knowing that I know. deceived in knowing that I know. For, as I know that I am, so I For, as I know that I am, so I know this also, that I know.”know this also, that I know.”