9766
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Study vagueness first by its logic, then by its truth-conditions, and then its metaphysics [Fine,K]
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Full Idea:
My investigation of vagueness began with the question 'What is the correct logic of vagueness?', which led to the further question 'What are the correct truth-conditions for a vague language?', which led to questions of meaning and existence.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], Intro)
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A reaction:
This is the most perfect embodiment of the strategy of analytical philosophy which I have ever read. It is the strategy invented by Frege in the 'Grundlagen'. Is this still the way to go, or has this pathway slowly sunk into the swamp?
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9775
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Excluded Middle, and classical logic, may fail for vague predicates [Fine,K]
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Full Idea:
Maybe classical logic fails for vagueness in Excluded Middle. If 'H bald ∨ ¬(H bald)' is true, then one disjunct is true. But if the second is true the first is false, and the sentence is either true or false, contrary to the borderline assumption.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], 4)
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A reaction:
Fine goes on to argue against the implication that we need a special logic for vague predicates.
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18084
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When successive variable values approach a fixed value, that is its 'limit' [Cauchy]
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Full Idea:
When the values successively attributed to the same variable approach indefinitely a fixed value, eventually differing from it by as little as one could wish, that fixed value is called the 'limit' of all the others.
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From:
Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4
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A reaction:
This seems to be a highly significan proposal, because you can now treat that limit as a number, and adds things to it. It opens the door to Cantor's infinities. Is the 'limit' just a fiction?
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9768
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Vagueness is semantic, a deficiency of meaning [Fine,K]
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Full Idea:
I take vagueness to be a semantic feature, a deficiency of meaning. It is to be distinguished from generality, undecidability, and ambiguity.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], Intro)
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A reaction:
Sounds good. If we cut nature at the joints with our language, then nature is going to be too subtle and vast for our finite and gerrymandered language, and so it will break down in tricky situations. But maybe epistemology precedes semantics?
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9776
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A thing might be vaguely vague, giving us higher-order vagueness [Fine,K]
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Full Idea:
There is a possibility of 'higher-order vagueness'. The vague may be vague, or vaguely vague, and so on. If J has few hairs on his head than H, then he may be a borderline case of a borderline case.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], 5)
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A reaction:
Such slim grey areas can also be characterised as those where you think he is definitely bald, but I am not so sure.
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9770
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Logical connectives cease to be truth-functional if vagueness is treated with three values [Fine,K]
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Full Idea:
With a three-value approach, if P is 'blob is pink' and R is 'blob is red', then P&P is indefinite, but P&R is false, and P∨P is indefinite, but P∨R is true. This means the connectives & and ∨ are not truth-functional.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], 1)
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A reaction:
The point is that there could then be no logic in any way classical for vague sentences and three truth values. A powerful point.
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9773
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With the super-truth approach, the classical connectives continue to work [Fine,K]
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Full Idea:
With the super-truth approach, if P is 'blob is pink' and R is 'blob is red', then P&R is false, and P∨R is true, since one of P and R is true and one is false in any complete and admissible specification. It encompasses all 'penumbral truths'.
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From:
Kit Fine (Vagueness, Truth and Logic [1975], 3)
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A reaction:
[See Idea 9767 for the super-truth approach, and Idea 9770 for a contrasting view] The approach, which seems quite appealing, is that we will in no circumstances give up basic classical logic, but we will make maximum concessions to vagueness.
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