Combining Texts

All the ideas for 'Locke on Essences and Kinds', 'Transworld Heir Lines' and 'Investigations in the Foundations of Set Theory I'

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24 ideas

2. Reason / D. Definition / 8. Impredicative Definition
15924 Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Zermelo, by Lavine]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
17608 We take set theory as given, and retain everything valuable, while avoiding contradictions [Zermelo]
17607 Set theory investigates number, order and function, showing logical foundations for mathematics [Zermelo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
10870 ZFC: Existence, Extension, Specification, Pairing, Unions, Powers, Infinity, Choice [Zermelo, by Clegg]
13012 Zermelo published his axioms in 1908, to secure a controversial proof [Zermelo, by Maddy]
17609 Set theory can be reduced to a few definitions and seven independent axioms [Zermelo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
13017 Zermelo introduced Pairing in 1930, and it seems fairly obvious [Zermelo, by Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
13015 Zermelo used Foundation to block paradox, but then decided that only Separation was needed [Zermelo, by Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / m. Axiom of Separation
13020 The Axiom of Separation requires set generation up to one step back from contradiction [Zermelo, by Maddy]
13486 Not every predicate has an extension, but Separation picks the members that satisfy a predicate [Zermelo, by Hart,WD]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
11970 Logicians like their entities to exhibit a maximum degree of purity [Kaplan]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
13487 In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals [Zermelo, by Hart,WD]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
18178 For Zermelo the successor of n is {n} (rather than n U {n}) [Zermelo, by Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
13027 Zermelo believed, and Von Neumann seemed to confirm, that numbers are sets [Zermelo, by Maddy]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
9627 Different versions of set theory result in different underlying structures for numbers [Zermelo, by Brown,JR]
9. Objects / C. Structure of Objects / 7. Substratum
11969 Models nicely separate particulars from their clothing, and logicians often accept that metaphysically [Kaplan]
9. Objects / D. Essence of Objects / 13. Nominal Essence
15642 If kinds depend only on what can be observed, many underlying essences might produce the same kind [Eagle]
15645 Nominal essence are the observable properties of things [Eagle]
15643 Nominal essence mistakenly gives equal weight to all underlying properties that produce appearances [Eagle]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
11971 The simplest solution to transworld identification is to adopt bare particulars [Kaplan]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
11973 Unusual people may have no counterparts, or several [Kaplan]
11972 Essence is a transworld heir line, rather than a collection of properties [Kaplan]
19. Language / A. Nature of Meaning / 8. Synonymy
11967 Sentences might have the same sense when logically equivalent - or never have the same sense [Kaplan]
26. Natural Theory / B. Natural Kinds / 4. Source of Kinds
15641 Kinds are fixed by the essential properties of things - the properties that make it that kind of thing [Eagle]