Combining Texts

All the ideas for 'Logical Necessity: Some Issues', 'Modal Logic' and 'Freedom of the Will and concept of a person'

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24 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]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell]
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 / A. Necessity / 6. Logical Necessity
Logical necessity overrules all other necessities [McFetridge]
The fundamental case of logical necessity is the valid conclusion of an inference [McFetridge, by Hale]
In the McFetridge view, logical necessity means a consequent must be true if the antecedent is [McFetridge, by Hale]
Logical necessity requires that a valid argument be necessary [McFetridge]
Traditionally, logical necessity is the strongest, and entails any other necessities [McFetridge]
It is only logical necessity if there is absolutely no sense in which it could be false [McFetridge]
The mark of logical necessity is deduction from any suppositions whatever [McFetridge]
10. Modality / B. Possibility / 2. Epistemic possibility
We assert epistemic possibility without commitment to logical possibility [McFetridge]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Objectual modal realists believe in possible worlds; non-objectual ones rest it on the actual world [McFetridge]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal realists hold that necessities and possibilities are part of the totality of facts [McFetridge]
16. Persons / B. Nature of the Self / 6. Self as Higher Awareness
Persons are distinguished by a capacity for second-order desires [Frankfurt]
A person essentially has second-order volitions, and not just second-order desires [Frankfurt]
16. Persons / F. Free Will / 1. Nature of Free Will
Free will is the capacity to choose what sort of will you have [Frankfurt]
20. Action / B. Preliminaries of Action / 2. Willed Action / a. Will to Act
The will is the effective desire which actually leads to an action [Frankfurt]
20. Action / B. Preliminaries of Action / 2. Willed Action / c. Agent causation
Freedom of action needs the agent to identify with their reason for acting [Frankfurt, by Wilson/Schpall]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
A 'wanton' is not a person, because they lack second-order volitions [Frankfurt]
A person may be morally responsible without free will [Frankfurt]