Combining Texts

All the ideas for 'Higher-Order Logic', 'Abstraction Reconsidered' and 'Naming and Necessity preface'

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25 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
16985 Possible worlds allowed the application of set-theoretic models to modal logic [Kripke]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
10301 The axiom of choice is controversial, but it could be replaced [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
10588 First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
10298 Some say that second-order logic is mathematics, not logic [Shapiro]
10299 If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
10300 Logical consequence can be defined in terms of the logical terminology [Shapiro]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
16982 A man has two names if the historical chains are different - even if they are the same! [Kripke]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
10290 Second-order variables also range over properties, sets, relations or functions [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10590 Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
10296 The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
10297 The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
10292 Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
10294 Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
10735 Abstraction from objects won't reveal an operation's being performed 'so many times' [Geach]
8. Modes of Existence / B. Properties / 11. Properties as Sets
10591 Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
9. Objects / F. Identity among Objects / 1. Concept of Identity
16981 With the necessity of self-identity plus Leibniz's Law, identity has to be an 'internal' relation [Kripke]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
4942 The indiscernibility of identicals is as self-evident as the law of contradiction [Kripke]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
16984 I don't think possible worlds reductively reveal the natures of modal operators etc. [Kripke]
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
9385 The very act of designating of an object with properties gives knowledge of a contingent truth [Kripke]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
4943 Instead of talking about possible worlds, we can always say "It is possible that.." [Kripke]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
16983 Probability with dice uses possible worlds, abstractions which fictionally simplify things [Kripke]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
10732 If concepts are just recognitional, then general judgements would be impossible [Geach]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
10731 For abstractionists, concepts are capacities to recognise recurrent features of the world [Geach]
18. Thought / E. Abstraction / 8. Abstractionism Critique
10733 The abstractionist cannot explain 'some' and 'not' [Geach]
10734 Only a judgement can distinguish 'striking' from 'being struck' [Geach]