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All the ideas for 'works', 'First-Order Modal Logic' and 'Truth and Predication'

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77 ideas

1. Philosophy / A. Wisdom / 2. Wise People
Tell cleverness from answers, but wisdom from questions [Mahfouz]
3. Truth / A. Truth Problems / 2. Defining Truth
A comprehensive theory of truth probably includes a theory of predication [Davidson]
3. Truth / A. Truth Problems / 3. Value of Truth
Antirealism about truth prevents its use as an intersubjective standard [Davidson]
3. Truth / A. Truth Problems / 8. Subjective Truth
'Epistemic' truth depends what rational creatures can verify [Davidson]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
There is nothing interesting or instructive for truths to correspond to [Davidson]
The Slingshot assumes substitutions give logical equivalence, and thus identical correspondence [Davidson]
Two sentences can be rephrased by equivalent substitutions to correspond to the same thing [Davidson]
3. Truth / D. Coherence Truth / 1. Coherence Truth
Coherence truth says a consistent set of sentences is true - which ties truth to belief [Davidson]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
We can explain truth in terms of satisfaction - but also explain satisfaction in terms of truth [Davidson]
Satisfaction is a sort of reference, so maybe we can define truth in terms of reference? [Davidson]
Axioms spell out sentence satisfaction. With no free variables, all sequences satisfy the truths [Davidson]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Truth is the basic concept, because Convention-T is agreed to fix the truths of a language [Davidson]
To define a class of true sentences is to stipulate a possible language [Davidson]
Many say that Tarski's definitions fail to connect truth to meaning [Davidson]
Tarski does not tell us what his various truth predicates have in common [Davidson]
3. Truth / H. Deflationary Truth / 1. Redundant Truth
Truth is basic and clear, so don't try to replace it with something simpler [Davidson]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Tarski is not a disquotationalist, because you can assign truth to a sentence you can't quote [Davidson]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Each line of a truth table is a model [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / a. Symbols of ML
Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn]
We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn]
The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn]
The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / b. Terminology of ML
A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn]
Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn]
A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn]
A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn]
Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / c. Derivation rules of ML
S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn]
If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn]
If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn]
Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn]
Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn]
Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn]
Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn]
Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn]
Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn]
Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn]
T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn]
D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn]
B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn]
4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn]
4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
The system K has no accessibility conditions [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
□P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn]
The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / e. System K4
The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 5. Epistemic Logic
In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn]
Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 6. Temporal Logic
F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn]
The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn]
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
'Satisfaction' is a generalised form of reference [Davidson]
8. Modes of Existence / B. Properties / 11. Properties as Sets
Treating predicates as sets drops the predicate for a new predicate 'is a member of', which is no help [Davidson]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn]
10. Modality / B. Possibility / 6. Probability
Probability can be constrained by axioms, but that leaves open its truth nature [Davidson]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
□ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn]
Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Predicates are a source of generality in sentences [Davidson]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
If we reject corresponding 'facts', we should also give up the linked idea of 'representations' [Davidson]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
You only understand an order if you know what it is to obey it [Davidson]
Utterances have the truth conditions intended by the speaker [Davidson]
19. Language / A. Nature of Meaning / 6. Meaning as Use
Meaning involves use, but a sentence has many uses, while meaning stays fixed [Davidson]
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
We recognise sentences at once as linguistic units; we then figure out their parts [Davidson]
19. Language / C. Assigning Meanings / 3. Predicates
Modern predicates have 'places', and are sentences with singular terms deleted from the places [Davidson]
The concept of truth can explain predication [Davidson]
19. Language / C. Assigning Meanings / 4. Compositionality
If you assign semantics to sentence parts, the sentence fails to compose a whole [Davidson]
19. Language / C. Assigning Meanings / 6. Truth-Conditions Semantics
Top-down semantic analysis must begin with truth, as it is obvious, and explains linguistic usage [Davidson]
19. Language / D. Propositions / 1. Propositions
'Humanity belongs to Socrates' is about humanity, so it's a different proposition from 'Socrates is human' [Davidson]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
The principle of charity says an interpreter must assume the logical constants [Davidson]
19. Language / F. Communication / 6. Interpreting Language / d. Metaphor
We indicate use of a metaphor by its obvious falseness, or trivial truth [Davidson]