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Single Idea 21621
[filed under theme 10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
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Full Idea
The inference from metaphysical necessity to a priori knowlability is, as Kripke has emphasized, fallacious. Indeed, metaphysical necessities cannot be assumed knowable in any way at all.
Gist of Idea
We can't infer metaphysical necessities to be a priori knowable - or indeed knowable in any way
Source
Timothy Williamson (Vagueness [1994], 7.4)
Book Ref
Williamson,Timothy: 'Vagueness' [Routledge 1996], p.203
A Reaction
The second sentence sounds like common sense. He cites Goldbach's Conjecture. A nice case of the procedural rule of keeping your ontology firmly separated from your epistemology. How is it? is not How do we know it?
The
41 ideas
from 'Vagueness'
21592
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Supervaluation keeps classical logic, but changes the truth in classical semantics
[Williamson]
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21589
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When bivalence is rejected because of vagueness, we lose classical logic
[Williamson]
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21591
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Vagueness is epistemic. Statements are true or false, but we often don't know which
[Williamson]
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21590
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Asking when someone is 'clearly' old is higher-order vagueness
[Williamson]
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21596
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Vagueness undermines the stable references needed by logic
[Williamson]
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21599
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A sorites stops when it collides with an opposite sorites
[Williamson]
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21600
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'Blue' is not a family resemblance, because all the blues resemble in some respect
[Williamson]
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21601
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A vague term can refer to very precise elements
[Williamson]
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21602
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Many-valued logics don't solve vagueness; its presence at the meta-level is ignored
[Williamson]
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21603
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You can't give a precise description of a language which is intrinsically vague
[Williamson]
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21604
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Supervaluation assigns truth when all the facts are respected
[Williamson]
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21607
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Supervaluation has excluded middle but not bivalence; 'A or not-A' is true, even when A is undecided
[Williamson]
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21606
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'Bivalence' is the meta-linguistic principle that 'A' in the object language is true or false
[Williamson]
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21605
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Excluded Middle is 'A or not A' in the object language
[Williamson]
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21612
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Or-elimination is 'Argument by Cases'; it shows how to derive C from 'A or B'
[Williamson]
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21611
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Formal semantics defines validity as truth preserved in every model
[Williamson]
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21608
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Truth-functionality for compound statements fails in supervaluation
[Williamson]
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21609
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Supervaluationism defines 'supertruth', but neglects it when defining 'valid'
[Williamson]
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21610
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Supervaluation adds a 'definitely' operator to classical logic
[Williamson]
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21613
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Supervaluationism cannot eliminate higher-order vagueness
[Williamson]
|
21614
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The 'nihilist' view of vagueness says that 'heap' is not a legitimate concept
[Williamson]
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21615
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References to the 'greatest prime number' have no reference, but are meaningful
[Williamson]
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18038
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The 't' and 'f' of formal semantics has no philosophical interest, and may not refer to true and false
[Williamson]
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21617
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We can say propositions are bivalent, but vague utterances don't express a proposition
[Williamson]
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21616
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Truth and falsity apply to suppositions as well as to assertions
[Williamson]
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21618
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If the vague 'TW is thin' says nothing, what does 'TW is thin if his perfect twin is thin' say?
[Williamson]
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21619
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If a heap has a real boundary, omniscient speakers would agree where it is
[Williamson]
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21620
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The epistemic view says that the essence of vagueness is ignorance
[Williamson]
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21621
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We can't infer metaphysical necessities to be a priori knowable - or indeed knowable in any way
[Williamson]
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21622
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If there is a true borderline of which we are ignorant, this drives a wedge between meaning and use
[Williamson]
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21623
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True and false are not symmetrical; false is more complex, involving negation
[Williamson]
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21624
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It is known that there is a cognitive loss in identifying propositions with possible worlds
[Williamson]
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21625
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The vagueness of 'heap' can remain even when the context is fixed
[Williamson]
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9120
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Vagueness in a concept is its indiscriminability from other possible concepts
[Williamson]
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21626
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Knowing you know (KK) is usually denied if the knowledge concept is missing, or not considered
[Williamson]
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21627
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We have inexact knowledge when we include margins of error
[Williamson]
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21630
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If fuzzy edges are fine, then why not fuzzy temporal, modal or mereological boundaries?
[Williamson]
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21629
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Equally fuzzy objects can be identical, so fuzziness doesn't entail vagueness
[Williamson]
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21632
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A river is not just event; it needs actual and counterfactual boundaries
[Williamson]
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21633
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Nominalists suspect that properties etc are our projections, and could have been different
[Williamson]
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21631
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To know, believe, hope or fear, one must grasp the thought, but not when you fail to do them
[Williamson]
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