Combining Texts

All the ideas for 'On Interpretation', 'Saundaranandakavya' and 'Introduction to the Theory of Logic'

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40 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
7910 Pursue truth with the urgency of someone whose clothes are on fire [Ashvaghosha]
2. Reason / B. Laws of Thought / 4. Contraries
1708 In "Callias is just/not just/unjust", which of these are contraries? [Aristotle]
3. Truth / B. Truthmakers / 10. Making Future Truths
1703 It is necessary that either a sea-fight occurs tomorrow or it doesn't, though neither option is in itself necessary [Aristotle]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
1704 Statements are true according to how things actually are [Aristotle]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
22272 Aristotle's later logic had to treat 'Socrates' as 'everything that is Socrates' [Potter on Aristotle]
9405 Square of Opposition: not both true, or not both false; one-way implication; opposite truth-values [Aristotle]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
9728 Modal Square 1: □P and ¬◊¬P are 'contraries' of □¬P and ¬◊P [Aristotle, by Fitting/Mendelsohn]
9729 Modal Square 2: ¬□¬P and ◊P are 'subcontraries' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
9730 Modal Square 3: □P and ¬◊¬P are 'contradictories' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
9731 Modal Square 4: □¬P and ¬◊P are 'contradictories' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn]
9732 Modal Square 5: □P and ¬◊¬P are 'subalternatives' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn]
9733 Modal Square 6: □¬P and ¬◊P are 'subalternatives' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
10888 Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
10889 The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo]
10890 A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
10886 Determinacy: an object is either in a set, or it isn't [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / l. Axiom of Specification
10887 Specification: Determinate totals of objects always make a set [Zalabardo]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
10897 A first-order 'sentence' is a formula with no free variables [Zalabardo]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
10893 Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo]
10899 Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo]
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
21593 In talking of future sea-fights, Aristotle rejects bivalence [Aristotle, by Williamson]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
1701 A prayer is a sentence which is neither true nor false [Aristotle]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
10896 Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
10898 The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo]
10902 We can do semantics by looking at given propositions, or by building new ones [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 2. Formal Truth
10892 We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
10895 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo]
10900 Logically true sentences are true in all structures [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
10894 A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo]
10901 Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
10903 A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
10891 If a set is defined by induction, then proof by induction can be applied to it [Zalabardo]
7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing
1706 Non-existent things aren't made to exist by thought, because their non-existence is part of the thought [Aristotle]
7. Existence / A. Nature of Existence / 5. Reason for Existence
1707 Maybe necessity and non-necessity are the first principles of ontology [Aristotle]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
2337 For Aristotle meaning and reference are linked to concepts [Aristotle, by Putnam]
19. Language / D. Propositions / 4. Mental Propositions
13763 Spoken sounds vary between people, but are signs of affections of soul, which are the same for all [Aristotle]
19. Language / F. Communication / 3. Denial
1705 It doesn't have to be the case that in opposed views one is true and the other false [Aristotle]
27. Natural Reality / D. Time / 1. Nature of Time / g. Growing block
1702 Things may be necessary once they occur, but not be unconditionally necessary [Aristotle]
29. Religion / C. Spiritual Disciplines / 3. Buddhism
7909 The Eightfold Path concerns morality, wisdom, and tranquillity [Ashvaghosha]
29. Religion / D. Religious Issues / 2. Immortality / d. Heaven
7908 At the end of a saint, he is not located in space, but just ceases to be disturbed [Ashvaghosha]