Scepticism

1. Scepticism

2. Scepticism • Beliefs (in a certain area) are • Unjustified (target: internalism) • Unreliable (target: externalism) • So, (a certain kind of) knowledge is impossible • Extreme form: all beliefs are unjustified or unreliable; all knowledge is impossible

3. Thesis and Recommendation • Thesis: Knowledge (of a certain kind) is impossible • Recommendation: So, one ought to _____. • Problem: How can the extreme skeptic get from the thesis to the recommendation? • It seems that it requires an inference • Extreme skepticism undercuts such inferences

4. Daoism: Zhuangzi (c. -350) • Intellectual distinctions correspond to nothing in reality • There’s no point to doing anything • Zhu Xi: “Laozi still wanted to do something, but Zhuangzi didn’t want to do anything at all.”

5. Identity of Contraries • Can we be completely objective? • No— the objective and subjective are intertwined • Objective —> subjective: you can reach objective knowledge only by depending on your own subjective mental states • Subjective —> objective: your being in a mental state depends on and gives rise to objective facts about you

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

7. Identity of All Things • We draw distinctions • But things aren’t distinct in the world • Everything is Dao • Everything is in the eye of the beholder • There is no objectivity • There is no knowledge

8. Variability • Variability: Things are perceived differently by different beings at different times • Undecidability: There is no neutral way to determine which perceptions are trustworthy • Sceptical thesis: Therefore, knowledge is impossible

9. Problem of the Criterion • Undecidability: There is no neutral way to tell which perceptions ought to be trusted • We need a criterion for determining this • But where could we get it? Even if we could get one, we couldn’t justify it

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

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

12. Zhuangzi’s Recommendation • “The true sage rejects all distinctions of this and that. He takes his refuge in Dao and places himself in subjective relation with all things.” • But how can he justify his recommendation? • Does it follow from his thesis? • Does he know it?

13. Philo of Alexandria (-20 - 40) • First to attempt project of reconciling Jewish scriptures with Greek philosophy • Tries to construct sceptical arguments without metaphysical presuppositions in “On Drunkenness”

14. Variability • Variation in perception among different species, different people, even same person on different occasions • How do we know which portray reality accurately?

15. Argument from Illusion • We often misperceive things • There is no way to tell when we’re misperceiving things • So, on any given occasion, we might be misperceiving things

16. Comparison • We know, not things in themselves, but things in relation to other things— including us • We know things only as they relate to us • We can’t distinguish what’s really in the object from what we are contributing

17. Zeno’s Paradoxes • Arguments against possibility of motion • Runner: one must first go halfway. . . . • Achilles and the Tortoise: The tortoise gets a head start; Achilles must first get to its starting point, but by then it has moved on

18. Sextus Empiricus (c. 200) • We can’t tell what’s in the object and what we contribute • Knowledge of “external underlying objects” is impossible • Recommendation: suspend judgment

19. Problem of the Criterion, 2 • Is there a criterion of truth? • To settle this, we need a criterion • But that’s what’s at issue! • Dogmatist must argue in a circle, • Or face infinite regress

20. Suspension & Ataraxia • Suspension of judgment —> peace of mind (ataraxia) • But the sceptic can’t know this, or even assert it • It just happens

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

22. Nagarjuna (c. 1000) • Mahayana Buddhist, 14th Indian Zen patriarch • Founder of Madhyamika Buddhism • Destroy theorizing • Leave ordinary life alone: “For we do not speak without accepting, for practical purposes, the work-a-day world”

23. Attack on pramanas • I know something because it arises from a reliable source of knowledge • But how do I know that source of knowledge is reliable? • Need a pramana of pramanas, etc.— infinite regress

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

25. Pramana of pramanas • Sources of knowledge: perception, analogy, testimony, inference • Knowledge is justified only if we know we’re using the appropriate source • What could be source of knowledge for that?

26. Quietism • If knowledge is impossible, how can we know the truth of scepticism? • Isn’t scepticism unreliable or unjustified? • “If I would make any proposition whatever, then by that I would have a logical error; But I do not make a proposition, therefore I am not in error.”

27. Nyaya Response • We don’t need a pramana for pramanas • Means of knowledge (pramanas) and objects of knowledge (prameyas) support each other • Sutra 16: Just as the 'measuring instrument' (which usually has the status of a pramana) can be a prameya as well (i.e. when its own accuracy is subject to investigation).

28. Scales • Analogy: scales • How do we test the reliability of a scale? • We compare weights it gives for objects with known weights by other scales • We don’t need a “scale of scales”

29. Nyaya Coherentism • No foundation, no given • One thing may be justifier or justified, depending on circumstances • Epistemic role depends on context

30. Luminosity • Sutra 19: . . . these (i.e. perception etc.) are apprehended in the same way as the light of a lamp. • Light can be both means of seeing and the thing seen

31. Gangesa (c. 1350) • Local doubt (e.g., eyes, scale): we doubt when something anomalous happens, and resolve as in the Nyaya-sutra • Global doubt: we have no reason to entertain; makes no sense to say everything is anomaly

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

33. Augustine (354-430) • Logical and mathematical truths can be known, even if sceptical arguments succeed • “I am certain that either there is only one world or there are more worlds than one. I am likewise certain that if there are more worlds than one, their number is either finite or infinite.”

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

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

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