Combining Texts

All the ideas for 'Set Theory and related topics (2nd ed)', 'An Introduction to Modal Logic' and 'Essential vs Accidental Properties'

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11 ideas

4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
9540 A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
9541 The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
9543 The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / e. Equivalence classes
8920 Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz]
5. Theory of Logic / K. Features of Logics / 4. Completeness
9544 A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
10938 The extremes of essentialism are that all properties are essential, or only very trivial ones [Rami]
9. Objects / D. Essence of Objects / 3. Individual Essences
10940 An 'individual essence' is possessed uniquely by a particular object [Rami]
9. Objects / D. Essence of Objects / 5. Essence as Kind
10939 'Sortal essentialism' says being a particular kind is what is essential [Rami]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
10934 Unlosable properties are not the same as essential properties [Rami]
10. Modality / A. Necessity / 3. Types of Necessity
10933 Physical possibility is part of metaphysical possibility which is part of logical possibility [Rami]
10. Modality / B. Possibility / 2. Epistemic possibility
10932 If it is possible 'for all I know' then it is 'epistemically possible' [Rami]