Combining Philosophers

All the ideas for Anaxarchus, Rod Girle and Joseph Butler

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23 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]
There are three axiom schemas for propositional logic [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 / 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 logic has four basic modal negation equivalences [Girle]
Modal logics were studied in terms of axioms, but now possible worlds semantics is added [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 / H. Proof Systems / 5. Tableau Proof
If an argument is invalid, a truth tree will indicate a counter-example [Girle]
9. Objects / F. Identity among Objects / 5. Self-Identity
Everything is what it is, and not another thing [Butler]
9. Objects / F. Identity among Objects / 9. Sameness
A tree remains the same in the popular sense, but not in the strict philosophical sense [Butler]
10. Modality / A. Necessity / 3. Types of Necessity
Analytic truths are divided into logically and conceptually necessary [Girle]
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]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
Despite consciousness fluctuating, we are aware that it belongs to one person [Butler]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / a. Memory is Self
If consciousness of events makes our identity, then if we have forgotten them we didn't exist then [Butler]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / c. Inadequacy of mental continuity
Consciousness presupposes personal identity, so it cannot constitute it [Butler]
16. Persons / D. Continuity of the Self / 5. Concerns of the Self
If the self changes, we have no responsibilities, and no interest in past or future [Butler]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Butler exalts conscience, but it may be horribly misleading [Anscombe on Butler]