Combining Texts

All the ideas for 'Euthyphro', 'Modal Logics and Philosophy' and 'Some Remarks on Essentialism'

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22 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic

7786	Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]

7798	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

7799	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

7797	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

7794	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

7793	◊p → □◊p is the hallmark of S5 [Girle]

7795	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

7787	Possible worlds logics use true-in-a-world rather than true [Girle]

7788	Modal logic has four basic modal negation equivalences [Girle]

7796	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

7789	Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle]

5. Theory of Logic / H. Proof Systems / 5. Tableau Proof

7790	If an argument is invalid, a truth tree will indicate a counter-example [Girle]

9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties

13952

Essentialism says some of a thing's properties are necessary, and could not be absent [Cartwright,R]

9. Objects / D. Essence of Objects / 14. Knowledge of Essences

13954

The difficulty in essentialism is deciding the grounds for rating an attribute as essential [Cartwright,R]

9. Objects / D. Essence of Objects / 15. Against Essentialism

13955

Essentialism is said to be unintelligible, because relative, if necessary truths are all analytic [Cartwright,R]

9. Objects / F. Identity among Objects / 3. Relative Identity

13953

An act of ostension doesn't seem to need a 'sort' of thing, even of a very broad kind [Cartwright,R]

10. Modality / A. Necessity / 3. Types of Necessity

7800	Analytic truths are divided into logically and conceptually necessary [Girle]

10. Modality / B. Possibility / 1. Possibility

7801	Possibilities can be logical, theoretical, physical, economic or human [Girle]

10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds

7792	A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle]

13. Knowledge Criteria / E. Relativism / 6. Relativism Critique

335	Do the gods also hold different opinions about what is right and honourable? [Plato]

28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question

336	Is what is pious loved by the gods because it is pious, or is it pious because they love it? (the 'Euthyphro Question') [Plato]

337	It seems that the gods love things because they are pious, rather than making them pious by loving them [Plato]