Combining Texts

All the ideas for 'A Puzzle about Belief', 'What is the Basis of Moral Obligation?' and 'Logical Necessity'

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16 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
In philosophy the truth can only be reached via the ruins of the false [Prichard]
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 / 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 / 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]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Puzzled Pierre has two mental files about the same object [Recanati on Kripke]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / c. Particularism
I see the need to pay a debt in a particular instance, and any instance will do [Prichard]
The complexities of life make it almost impossible to assess morality from a universal viewpoint [Prichard]
23. Ethics / D. Deontological Ethics / 2. Duty
Seeing the goodness of an effect creates the duty to produce it, not the desire [Prichard]