Combining Texts

All the ideas for 'Philosophy as a way of life', 'Morality as system of hypothetical imperatives' and 'Modal Logics and Philosophy'

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23 ideas

1. Philosophy / D. Nature of Philosophy / 6. Hopes for Philosophy
It is no longer possible to be a sage, but we can practice the exercise of wisdom [Hadot]
2. Reason / A. Nature of Reason / 2. Logos
The logos represents a demand for universal rationality [Hadot]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
There are three axiom schemas for propositional logic [Girle]
Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
Proposition logic has definitions for its three operators: or, and, and identical [Girle]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
There are seven modalities in S4, each with its negation [Girle]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
◊p → □◊p is the hallmark of S5 [Girle]
S5 has just six modalities, and all strings can be reduced to those [Girle]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Possible worlds logics use true-in-a-world rather than true [Girle]
Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle]
Modal logic has four basic modal negation equivalences [Girle]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle]
5. Theory of Logic / H. Proof Systems / 5. Tableau Proof
If an argument is invalid, a truth tree will indicate a counter-example [Girle]
10. Modality / A. Necessity / 3. Types of Necessity
Analytic truths are divided into logically and conceptually necessary [Girle]
10. Modality / B. Possibility / 1. Possibility
Possibilities can be logical, theoretical, physical, economic or human [Girle]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / e. Ethical cognitivism
Morality is inescapable, in descriptive words such as 'dishonest', 'unjust' and 'uncharitable' [Foot]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / b. Rational ethics
Reason is not a motivator of morality [Foot, by Hacker-Wright]
Rejecting moral rules may be villainous, but it isn't inconsistent [Foot]
22. Metaethics / C. The Good / 3. Pleasure / b. Types of pleasure
The pleasure of existing is the only genuine pleasure [Hadot]
23. Ethics / D. Deontological Ethics / 1. Deontology
Saying we 'ought to be moral' makes no sense, unless it relates to some other system [Foot]
23. Ethics / D. Deontological Ethics / 4. Categorical Imperative
Morality no more consists of categorical imperatives than etiquette does [Foot]