Combining Texts

All the ideas for 'On What Grounds What', 'Introduction to 'Virtues of Authenticity'' and 'A Tour through Mathematical Logic'

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34 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
13734 Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J]
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
13751 If you tore the metaphysics out of philosophy, the whole enterprise would collapse [Schaffer,J]
2. Reason / B. Laws of Thought / 6. Ockham's Razor
13743 We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
13520 A 'tautology' must include connectives [Wolf,RS]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
13524 Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / d. Universal quantifier ∀
13521 Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS]
13522 Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / e. Existential quantifier ∃
13523 Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / e. Axiom of the Empty Set IV
13529 Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / n. Axiom of Comprehension
13526 Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
13534 In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS]
13535 First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
13519 Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS]
13531 Model theory reveals the structures of mathematics [Wolf,RS]
13532 Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS]
13533 First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
13537 An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
13539 The LST Theorem is a serious limitation of first-order logic [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 4. Completeness
13538 If a theory is complete, only a more powerful language can strengthen it [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 10. Monotonicity
13525 Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
13530 An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
13518 Modern mathematics has unified all of its objects within set theory [Wolf,RS]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
13741 If 'there are red roses' implies 'there are roses', then 'there are prime numbers' implies 'there are numbers' [Schaffer,J]
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
13748 Grounding is unanalysable and primitive, and is the basic structuring concept in metaphysics [Schaffer,J]
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
13747 Supervenience is just modal correlation [Schaffer,J]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
13744 The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J]
7. Existence / E. Categories / 4. Category Realism
13739 Maybe categories are just the different ways that things depend on basic substances [Schaffer,J]
8. Modes of Existence / D. Universals / 6. Platonic Forms / a. Platonic Forms
17945 Forms are not a theory of universals, but an attempt to explain how predication is possible [Nehamas]
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
17946 Only Tallness really is tall, and other inferior tall things merely participate in the tallness [Nehamas]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
13742 There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J]
13752 The notion of 'grounding' can explain integrated wholes in a way that mere aggregates can't [Schaffer,J]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
13749 Belief in impossible worlds may require dialetheism [Schaffer,J]
11. Knowledge Aims / A. Knowledge / 2. Understanding
17944 'Episteme' is better translated as 'understanding' than as 'knowledge' [Nehamas]
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
13740 'Moorean certainties' are more credible than any sceptical argument [Schaffer,J]