Ideas from 'Vagueness' by Timothy Williamson [1994], by Theme Structure

[found in 'Vagueness' by Williamson,Timothy [Routledge 1996,0-415-13980-5]].

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3. Truth / A. Truth Problems / 5. Truth Bearers
Truth and falsity apply to suppositions as well as to assertions
3. Truth / A. Truth Problems / 7. Falsehood
True and false are not symmetrical; false is more complex, involving negation
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
Many-valued logics don't solve vagueness; its presence at the meta-level is ignored
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Formal semantics defines validity as truth preserved in every model
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
'Bivalence' is the meta-linguistic principle that 'A' in the object language is true or false
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Excluded Middle is 'A or not A' in the object language
5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
Or-elimination is 'Argument by Cases'; it shows how to derive C from 'A or B'
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / b. The Heap paradox ('Sorites')
A sorites stops when it collides with an opposite sorites
7. Existence / D. Theories of Reality / 10. Vagueness / a. Problem of vagueness
Vagueness undermines the stable references needed by logic
A vague term can refer to very precise elements
When bivalence is rejected because of vagueness, we lose classical logic
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
Equally fuzzy objects can be identical, so fuzziness doesn't entail vagueness
7. Existence / D. Theories of Reality / 10. Vagueness / c. Vagueness as ignorance
Vagueness is epistemic. Statements are true or false, but we often don't know which
If a heap has a real boundary, omniscient speakers would agree where it is
The epistemic view says that the essence of vagueness is ignorance
If there is a true borderline of which we are ignorant, this drives a wedge between meaning and use
Vagueness in a concept is its indiscriminability from other possible concepts
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
The 'nihilist' view of vagueness says that 'heap' is not a legitimate concept
We can say propositions are bivalent, but vague utterances don't express a proposition
If the vague 'TW is thin' says nothing, what does 'TW is thin if his perfect twin is thin' say?
The vagueness of 'heap' can remain even when the context is fixed
7. Existence / D. Theories of Reality / 10. Vagueness / e. Higher-order vagueness
Asking when someone is 'clearly' old is higher-order vagueness
7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
Supervaluationism defines 'supertruth', but neglects it when defining 'valid'
Supervaluation adds a 'definitely' operator to classical logic
Supervaluationism cannot eliminate higher-order vagueness
Supervaluation keeps classical logic, but changes the truth in classical semantics
You can't give a precise description of a language which is intrinsically vague
Supervaluation assigns truth when all the facts are respected
Supervaluation has excluded middle but not bivalence; 'A or not-A' is true, even when A is undecided
Truth-functionality for compound statements fails in supervaluation
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
Nominalists suspect that properties etc are our projections, and could have been different
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
If fuzzy edges are fine, then why not fuzzy temporal, modal or mereological boundaries?
9. Objects / E. Objects over Time / 8. Continuity of Rivers
A river is not just event; it needs actual and counterfactual boundaries
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
We can't infer metaphysical necessities to be a priori knowable - or indeed knowable in any way
11. Knowledge Aims / A. Knowledge / 1. Knowledge
We have inexact knowledge when we include margins of error
13. Knowledge Criteria / A. Justification Problems / 1. Justification / a. Justification issues
Knowing you know (KK) is usually denied if the knowledge concept is missing, or not considered
18. Thought / A. Modes of Thought / 2. Propositional Attitudes
To know, believe, hope or fear, one must grasp the thought, but not when you fail to do them
18. Thought / D. Concepts / 4. Structure of Concepts / h. Family resemblance
'Blue' is not a family resemblance, because all the blues resemble in some respect
19. Language / B. Reference / 1. Reference theories
References to the 'greatest prime number' have no reference, but are meaningful
19. Language / C. Assigning Meanings / 2. Semantics
The 't' and 'f' of formal semantics has no philosophical interest, and may not refer to true and false
19. Language / D. Propositions / 2. Abstract Propositions / b. Propositions as possible worlds
It is known that there is a cognitive loss in identifying propositions with possible worlds