Combining Texts

All the ideas for 'Philosophy of Language', 'Completeness of Axioms of Logic' and 'Modal Logics and Philosophy'

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25 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
There are three axiom schemas for propositional logic [Girle]
Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
Proposition logic has definitions for its three operators: or, and, and identical [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle]
4. Formal Logic / C. Predicate Calculus PC / 3. Completeness of PC
Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
The interest of quantified modal logic is its metaphysical necessity and essentialism [Soames]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
There are seven modalities in S4, each with its negation [Girle]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
◊p → □◊p is the hallmark of S5 [Girle]
S5 has just six modalities, and all strings can be reduced to those [Girle]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Possible worlds logics use true-in-a-world rather than true [Girle]
Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle]
Modal logic has four basic modal negation equivalences [Girle]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / a. Descriptions
Indefinite descriptions are quantificational in subject position, but not in predicate position [Soames]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
Recognising the definite description 'the man' as a quantifier phrase, not a singular term, is a real insight [Soames]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
The universal and existential quantifiers were chosen to suit mathematics [Soames]
5. Theory of Logic / H. Proof Systems / 5. Tableau Proof
If an argument is invalid, a truth tree will indicate a counter-example [Girle]
10. Modality / A. Necessity / 3. Types of Necessity
Analytic truths are divided into logically and conceptually necessary [Girle]
10. Modality / A. Necessity / 5. Metaphysical Necessity
There are more metaphysically than logically necessary truths [Soames]
We understand metaphysical necessity intuitively, from ordinary life [Soames]
10. Modality / B. Possibility / 1. Possibility
Possibilities can be logical, theoretical, physical, economic or human [Girle]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
To study meaning, study truth conditions, on the basis of syntax, and representation by the parts [Soames]
Tarski's account of truth-conditions is too weak to determine meanings [Soames]
19. Language / D. Propositions / 4. Mental Propositions
We should use cognitive states to explain representational propositions, not vice versa [Soames]