October 31, 2010
Posted in Uncategorized tagged epistemic possibility; metaphysical possibility at 9:15 pm by Lao Wan
P is epistemically possible iff it is not knowable a priori that P is false. E.g. we don’t know a priori that Hesperus is not identical to Phosphorus, therefore it is epistemically possible they are identical. Besides, it is also epistemically possible that they are not identical. On the other hand, we know a priori that “P and not P” is false, then it is epistemically impossible. (To specify this “definition”, a definition of “apriority” might be necessary, or necessary & sufficient conditions are to be specified. And I don’t know how to distinguish this from logical possibilities, because we have to decide if logical truth are knowable a priori.)
Notice that the relevant statements are about what the case could turn out to be in our actual world, and they are irrelevant to other possible worlds
P is metaphysically possible iff P is true in some counterfactual situation, i.e. P is true in a possible world.
P is metaphysically necessary iff P is true in the actual world (according to Kripke).
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Taking “water is H2O” for instance, since we don’t know a priori that “water is not H2O” (and in the actual world water is exactly H2O), we can conclude that “water is H2O” is epistemically possible (and metaphysically necessary if Kripke is right).
As for “Hitler could have been victorious in WWII” (borrowed from wikipedia), this sentence is in subjunctive mood, from which we know it is talking about counterfactual situation and relevant to metaphysical possibility. Since we can imagine in another possible world where Hitler did beat Allied forces, “Hitler could have been victorious in WWII” is metaphysically possible.
I guess that the mood of a sentence decides whether it is about epistemic possibility or metaphysic possibility, but it might not be exclusive. For example, “water is H2O” is in an indicative mood, we mostly talk about the epistemic possibility of it, but we can also discuss its metaphysical possibility. However, sentences in subjunctive mood seem to be totally about metaphysical possibility.
After we decide what kind of possibility this sentence mainly about, we use the standard of apriority, conceivability (if conceivability is equavalent to metaphysical possibility) or something else to make the conclusion.
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April 1, 2010
Posted in epistemology, philosophy of language tagged coreferential, epistemology, justification, puzzle about belief, represent, substitutivity at 9:17 am by Lao Wan
An epistemological approach to the puzzle about belief
The puzzle about belief has been one of the central topics in the philosophy of language since it was provoked by Kripke in 1979. However, I will see it from a viewpoint of epistemology in this paper. The popular theories and arguments concerning the puzzle are to be examined and evaluated by a standard of epistemological justification. After that, I will try to establish a proper relation among semantic, metaphysical and epistemological accounts relevant with the topic.
- The Puzzle about Belief
Kripke (1979) first spell out the puzzle as follows:
Pierre is rational French who cannot speak English. He lived in Paris, and heard about the beauty of the far city “Londeres”. After seeing a postcard on which there is a beautiful picture of London, he asserted that “Londeres est jolie.” Years later, he move to London, and lived in somewhere not so amazing. And after learning some English not by way of translation, he asserted that “London is not pretty.” If his assertion that “Londeres est jolie” can be appropriately translated as “London is pretty.” Then since he sincerely asserted “Londeres est jolie”, he seems to believe that London is pretty. But he also asserted “London is not pretty” sincerely. It seems he has contradictory beliefs, and therefore not rational. But this is contradictory with the assumption that Pierre is rational. Read the rest of this entry »
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March 28, 2010
Posted in epistemology, metaphysics, philosophy of language tagged codesignative names, puzzle about belief, referent, sense at 10:23 pm by Lao Wan
Let’s modify this story a little. John has a good friend Tom, and they often play together. But “Billa” is a pet name for Tom, which is only called by family members and John don’t know it. One day, Tom ran away from school, and John knew it. Tom’s mother came and asked him, “Do you know where Billa is?” John thought and sincerely answered “I don’t know.” So, in this case did John lie? By intuition, we would say that John was innocent, because he did not know that Tom is Bella. But let’s see what the answer a Millian would give by a formal argument:
[L] 1
(1) Tom=Billa /Assumption
(2) Where Tom is = Where Billa is / (F) 2
(3) KJ(where Tom is)→KJ(where Billa is) /(2), (C)3
(4) KJ(where Tom is) /Assumption
(5) KJ(where Billa is) /(2)(3),MP
From this argument, the Millian would conclude that John actually knew where Billa is. And therefore the Millian will claim that John lied to Tom’s Mom. But this is what most people cannot agree, John was innocent! Surely, this is not an ethical problem. Rather, it is about John’s knowledge, whether he knew where Billa was. But it is not our purpose here to talk about the nature of knowledge or to analyze the concept of “knowing”.4 Let’s scrutinize what, if any, has gone wrong in [L]. It seems that the most suspicious step is (3), where an unfamiliar principle is applied. It seems that it is this principle lead to the unacceptable result. To discuss about the closure principle here might be accused of digression for this principle is one of the center topics in epistemology. However, if one accepts Millianism, then he also commits himself to this very version of closure principle. According to Millianism, “all there is to a name is its referent” (C.f Frances 1988); then a knowledge about T would be equivalent to a knowledge about B, if T and B are coreferential names. As a result, if T and B are referential names and one knows that T is F, then this agent must also know that B is F. But the story above shows us that John did not know where Billa was and we cannot infer by this principle that he did. Therefore, this principle is problematic. Read the rest of this entry »
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March 21, 2010
Posted in epistemology, philosophy of language tagged a priori, apriority, belief, knowledge at 8:45 pm by Lao Wan
© Lao Wan 2010
In this paper, I will develop an account of apriority and necessity at first. After that, I will analyze the phenomena recognized as the contingent a priori and the necessary a posteriori.
Apriority is a property applies to justification and knowledge. Generally speaking, a justification is to be a priori means that it must be independent of experience; and a priori knowledge, as Kant said, is “knowledge that is absolutely independent of all experience” (Kant 1787, 43).1 While Kant’s accounts might be misleading, for there are putative examples of a priori knowledge do have empirical contents, for example “the length of stick S is one meter at time T”2. A less ambiguous formulation is given by Kripke in Naming and Necessity, that is, “it’s possible (whether we do or do not in fact know it independently of any experience) to know this independently of any experience” (Kripke 1980, 34). More specifically, a proposition p can be known a priori only if, necessarily, if once the agent understands p, he will come to know p without any empirical investigation, simply by reflecting on and reasoning about it.
Read the rest of this entry »
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