Combining Texts

All the ideas for 'Sisyphus (lost)', 'Logical Necessity' and 'Identity and Necessity'

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19 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
The logic of metaphysical necessity is S5 [Rumfitt]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt]
There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt]
We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt]
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
We may fix the reference of 'Cicero' by a description, but thereafter the name is rigid [Kripke]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
The function of names is simply to refer [Kripke]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt]
10. Modality / A. Necessity / 3. Types of Necessity
A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt]
A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt]
Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt]
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
It is necessary that this table is not made of ice, but we don't know it a priori [Kripke]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
A 'rigid designator' designates the same object in all possible worlds [Kripke]
We cannot say that Nixon might have been a different man from the one he actually was [Kripke]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Modal statements about this table never refer to counterparts; that confuses epistemology and metaphysics [Kripke]
17. Mind and Body / A. Mind-Body Dualism / 7. Zombies
Identity theorists must deny that pains can be imagined without brain states [Kripke]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / e. Modal argument
Pain, unlike heat, is picked out by an essential property [Kripke]