Combining Texts

All the ideas for 'fragments/reports', 'Sophistical Refutations' and 'Modal Logic'

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15 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Even pointing a finger should only be done for a reason [Epictetus]
2. Reason / A. Nature of Reason / 1. On Reason
Didactic argument starts from the principles of the subject, not from the opinions of the learner [Aristotle]
2. Reason / A. Nature of Reason / 4. Aims of Reason
Reasoning is a way of making statements which makes them lead on to other statements [Aristotle]
2. Reason / C. Styles of Reason / 1. Dialectic
Dialectic aims to start from generally accepted opinions, and lead to a contradiction [Aristotle]
2. Reason / C. Styles of Reason / 3. Eristic
Competitive argument aims at refutation, fallacy, paradox, solecism or repetition [Aristotle]
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 / E. Structures of Logic / 2. Logical Connectives / d. and
'Are Coriscus and Callias at home?' sounds like a single question, but it isn't [Aristotle]
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 / D. Essence of Objects / 10. Essence as Species
Generic terms like 'man' are not substances, but qualities, relations, modes or some such thing [Aristotle]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Only if two things are identical do they have the same attributes [Aristotle]
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]