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| Disputed term/author/ism | Author Vs Author |
Entry |
Reference |
|---|---|---|---|
| Skepticism | Nozick Vs Skepticism | II 197 Skepticism/Nozick: we do not try to refute the skeptic. VsSkepticism: other authors: 1) when he argues against knowledge, he already presupposes that it exists. 2) to accept it would be unreasonable, because it is more likely that his extreme conclusions are wrong than that all its premises are true. NozickVs. We do not have to convince the skeptic. We want to explain how knowledge is possible, therefore it is good to find hypotheses which we ourselves find acceptable! II 198 Skepticism/Nozick: Common Variant: claims that someone could believe something even though it is wrong. Perhaps caused by a demon or because he is dreaming or because he is a brain in a vat. But how do these possibilities adopted by the skeptic show that I do not know p? (3) if p were false, S would not believe that p (as above). If (3) is a necessary condition for knowledge that shows the possibility of the skeptic that there is no knowledge. Strong variant: R: Even if p were false, S would still believe that p II 199 This conditional with the same antecedent as (3) and contradictory consequent is incompatible with (3). If (3) is true, R is false. But R is stronger than skepticism requires. Because if (3) were wrong, S could still believe that p. The following conditional is weaker than R, it is merely the negation of (3): T: Not (not p > not (S believes that p)). ((s) >Range: weaker: negation of the entire conditional stronger: the same antecedent, opposite of the consequent ((s) not necessarily negation of consequent) Here: stronger: ".... would have to believe ..." - weaker.. "... could ...") Nozick: While R does not simply deny (3), it asserts its own conditional instead. The truth of (3) is not incompatible with a possible situation (here not possible world) where the person believes p, although p is false. (3) does not cover all possibilities: (3) not p > not (S believes p) That does not mean that in all situations where not p is true, S does not believe that p. Asserting this would mean to say that not p entails not (S believes p) (or logical implication) ((s) >Entailment). But subjunction (conditional) differs from entailment: So the existence of a possible situation in which p is wrong and S still believes p does not show that (3) is false. (? LL). (3) can be true even if there is a possible situation where not p and S believes that p. (3) speaks of the situation in which p is false. Not every possible situation where p is false is the situation that would prevail if p were false. Possible World: (3) speaks of the ~p world closest to our actual world. It speaks of the non-p neighborhood. Skepticism/SK/Terminology/Nozick: SK stands for the "possibilities of the skeptic": II 200 We could dream of being misled by an evil demon or being brains in a vat. These are attempts to refute (3): (3) if p were false, S would not believe that p. But these only attempts succeed if one of these possibilities(dream, vat, demon) prevails when p is false. I.e. only in the next non-p worlds. Even if we were in the vat, (3) could be true, i.e. although - as described by skeptics - p is false and S believes p. ((s) E.g. p: "I am in the Café": false, if I'm in the vat. But I would not believe to be the vat. That is what the skeptic means. If I do not believe the truth (that I am in the vat) and do not know, then my belief is wrong. But then p means "I'm not in the vat."). NozickVsSkepticism: when the skeptic describes a situation SK that would not prevail (sic), even if p were wrong, then this situation SK (vat) does not show that (3) is wrong and does not undermine our knowledge. (see below) ((s) i.e. from the perspective VsSkepticism: the skeptic asserts that all beliefs are wrong, but that is not yet the situation that we are all in the tank). This is just the preliminary consideration, the expected one follows in the next paragraph). Condition C: to exclude skeptical hypothesis: C: not-p > SK (vat situation) does not exist ((s) That is what the skeptic denies!). That excludes every skeptical situation that fulfills C. ((s) it is only about n-p cases). Skepticism: for a vat situation to show that we do not know that p, it must be a situation that could exist if p did not exist, and thus satisfies the negation of C: Negation of C: -not (not p > SK (vat situation) does not exist) Although the vat situations of the skeptic seem to show that (3) is wrong, they do not show it: they satisfy condition C and are therefore excluded! SkepticismVs: could ask why we know that if p were wrong, SK (vat) would not exist. But usually it asks something stronger: do we know that the vat situation does not exist? And if we do not know that, how can we know that p? ((s) reverse order). This brings us to the second way in which the vat situatios could show that we do not know that p: Skeptical results Knowledge/Nozick: according to our approach, S knows that the vat situation does not exist iff II 201 (1) vat situation does not exist (2) S believes that vat situation does not exist (3) If the vat situation existed, then S would not believe that the vat situation did not(!) exist. (4) If the vat situation did not exist, then S would believe that it does not exist. (3) is the necessary condition for knowledge! It follows from it that we do not know that we are not in the vat! Skepticism/Nozick: that is what the skeptic says. But is it not what we say ourselves? It is actually a feature of our approach that it provides this result! Vat/Demon/Descartes/Nozick: Descartes would say that proof of the existence of a good God would not allow us to be in the vat. Literature then focused on whether Descartes would succeed to obtain such evidence. II 202 Nozick: could a good God not have reasons to deceive us? According to Descartes his motives are unknowable for us. Cogito/Nozick: can "I think" only be produced by something existing? Not perhaps also by Hamlet, could we not be dreamed by someone who inspires "I think" in us? Descartes asked how we knew that we were not dreaming, he could also have asked whether we were dreamed about by someone. Def Doxastically Identical/Terminology/Nozick: is a possible situation for S with the current situation, if S believed exactly the same things (Doxa) in the situation. II 203 Skepticism: describes doxastically identical situations where nearly all the believed things are wrong. (Vat). Such possible worlds are possible, because we possess our knowledge through mediation, not directly. It's amazing how different doxastically identical worlds can be. What else could the skeptic hope for? Nozick pro skepticism: we agree that we do not know that "not-vat". II 204 But that does not keep me from knowing that I'm writing this! It is true, I believe it and I would not believe it if it were not true, and if it were true, I would believe it. I.e. our approach does not lead to general skepticism. However, we must ensure that it seems that the skeptic is right and that we do not know that we are not in the vat. VsSkepticism: we must examine its "short step" to the conclusion that we do not know these things, because either this step is wrong or our approach is incoherent. Not seclusion II 204 Completed/Incompleteness/Knowledge/Nozick: Skepticism: (wrongly) assumes that our knowledge is complete under known logical implication: if we progress from something known to something entailed, we allegedly do not leave the realm of knowledge. The skeptic tries the other way around, of course: if you do not know that q, and you know that p entails q, then it should follow that you do not know that p. E.g. ((s) If you do not know that you are not in the vat, and sitting here implies not being in the vat, then you do not know that you're sitting here, if you know that the implication exists. (contraposition).) Terminology: Contraposition: knowledge that p >>: entails Then the (skeptical) principle of closure under known implication is: P: K(p >> q) & Kp > Kq. II 205 Nozick: E.g. if you know that two sentences are incompatible, and you know that the first one is true, then you know that the negation of the second one is true. Contraposition: because you do not know the second one, you do not know the first. (FN 48) Vs: you could pick on the details and come to an iteration: the person might have forgotten inferences etc. Finally you would come to KK(p >> q) & KKp Kq: amplifies the antecedent and is therefore not favorable for the skeptics. II 206 NozickVsSkepticism: the whole principle P is false. Not only in detail. Knowledge is not closed under known logical implication. (FN 49) S knows that p if it has a true belief and fulfills (3) and (4). (3) and (4) are themselves not closed under known implication. (3) if p were false, S would not believe that p. If S knows that p, then the belief is that p contingent on the truth of p. And that is described by (3). Now it may be that p implies q (and S knows that), that he also believes that q, but this belief that q is not subjunktivically dependent on the truth of q. Then he does not fulfill (3') if q were wrong, S would not believe q. The situation where q is wrong could be quite different from the one where p is wrong. E.g. the fact that they were born in a certain city implies that they were born on the earth, but not vice versa. II 207 And pondering the respective situations would also be very different. Thus the belief would also be very different. Stronger/Weaker: if p implies q (and not vice versa), then not-q (negation of consequent) is much stronger than not-p (negation of the antecedent). Assuming various strengths there is no reason to assume that the belief would be the same in both situations. (Doxastically identical). Not even would the beliefs in one be a proper subset of the other! E.g. p = I'm awake and sitting on a chair in Jerusalem q = I'm not in the vat. The first entails the second. p entails q. And I know that. If p were wrong, I could be standing or lying in the same city or in a nearby one. ((s) There are more ways you can be outside of a vat than there are ways you can be inside). If q were wrong, I would have to be in a vat. These are clearly two different situations, which should make a big difference in what I believe. If p were wrong, I would not believe that p. If q were wrong, I would nevertheless still believe that q! Even though I know that p implies q. The reason is that (3) is not closed under known implication. It may be that (3) is true of one statement, but not of another, which is implied by it. If p entails q and we truthfully believe that p, then we do not have a false belief that q. II 208 Knowledge: if you know something, you cannot a have false belief about it. Nevertheless, although p implies q, we can have a false belief that q (not in vat)! "Would not falsely believe that" is in fact not completed under known implication either. If knowledge were merely true belief, it would be closed under implication. (Assuming that both statements are believed). Because knowledge is more than belief, we need additional conditions of which at least one must be open (not completed) under implication. Knowledge: a belief is only knowledge when it covaries with the fact. (see above). Problem: This does not yet ensure the correct type of connection. Anyway, it depends on what happens in situations where p is false. Truth: is what remains under implication. But a condition that does not mention the possible falseness, does not provide us covariance. Belief: a belief that covaries with the facts is not complete. II 209 Knowledge: and because knowledge involves such a belief, it is not completed, either. NozickVsSkepticism: he cannot simply deny this, because his argument that we do not know that we are not in the vat uses the fact that knowledge needs the covariance. But he is in contradiction, because another part of his argument uses the assumption that there is no covariance! According to this second part he concludes that you know nothing at all if you do not know that they are not in the vat. But this completion can only exist if the variation (covariance) does not exist. Knowledge/Nozick: is an actual relation that includes a connection (tracking, traceable track). And the track to p is different from that to q! Even if p implies q. NozickVsSkepticism: skepticism is right in that we have no connections to some certain truths (we are not in the vat), but he is wrong in that we are not in the correct relation to many other facts (truths). Including such that imply the former (unconnected) truth that we believe, but do not know. Skepticism/Nozick: many skeptics profess that they cannot maintain their position, except in situations where they rationally infer. E.g. Hume: II 210 Hume: after having spent three or four hours with my friends, my studies appear to me cold and ridiculous. Skepticism/Nozick: the arguments of the skeptic show (but they also show only) that we do not know that we are not in the vat. He is right in that we are not in connection with a fact here. NozickVsSkepticism: it does not show that we do not know other facts (including those that imply "not vat"). II 211 We have a connection to these other facts (e.g. I'm sittin here, reading). II 224f Method/Knowledge/Covariance/Nozick: I do not live in a world where pain behavior e is given and must be kept constant! - I.e. I can know h on the basis of e, which is variable! - And because it does not vary, it shows me that h ("he is in pain") is true. VsSkepticism: in reality it is not a question that is h not known, but "not (e and not h)" II 247 NozickVsSkepticism: there is a limit for the iteration of the knowledge operator K. "knowing knowledge" is sometimes interpreted as certainly knowing, but that is not meant here. Point: Suppose a person knows exactly that they are located on the 3rd level of knowledge: K³p (= KKKp), but not k4p. Suppose also that the person knows that they are not located on the 4th level. KK³p & not k4p. But KK³p is precisely k4p which has already been presumed as wrong! Therefore, it should be expected that if we are on a finite level Knp, we do not know exactly at what level we are. |
No I R. Nozick Philosophical Explanations Oxford 1981 No II R., Nozick The Nature of Rationality 1994 |
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