Combining Texts

All the ideas for 'Good and Evil', 'Intro to 'The Reason's Proper Study'' and 'Modal Logic'

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16 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
Normal system K has five axioms and rules [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
D is valid on every serial frame, but not where there are dead ends [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
In S5 all the long complex modalities reduce to just three, and their negations [Cresswell]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / c. Grelling's paradox
If 'x is heterological' iff it does not apply to itself, then 'heterological' is heterological if it isn't heterological [Hale/Wright]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
The incompletability of formal arithmetic reveals that logic also cannot be completely characterized [Hale/Wright]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
If structures are relative, this undermines truth-value and objectivity [Hale/Wright]
The structural view of numbers doesn't fit their usage outside arithmetical contexts [Hale/Wright]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
The neo-Fregean is more optimistic than Frege about contextual definitions of numbers [Hale/Wright]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Objects just are what singular terms refer to [Hale/Wright]
10. Modality / A. Necessity / 4. De re / De dicto modality
A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstracted objects are not mental creations, but depend on equivalence between given entities [Hale/Wright]
19. Language / E. Analyticity / 2. Analytic Truths
Many conceptual truths ('yellow is extended') are not analytic, as derived from logic and definitions [Hale/Wright]
22. Metaethics / C. The Good / 1. Goodness / a. Form of the Good
'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot]