Combining Philosophers

All the ideas for Rescher,N/Oppenheim,P, Ori Simchen and Max J. Cresswell

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12 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]
The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen]
The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen]
BF implies that if W possibly had a child, then something is possibly W's child [Simchen]
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 / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim]
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]
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Serious Actualism says there are no facts at all about something which doesn't exist [Simchen]