Combining Texts

All the ideas for 'Investigations in the Foundations of Set Theory I', 'General Draft' and 'Truthmakers and Converse Barcan Formula'

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28 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
22026 Philosophy is homesickness - the urge to be at home everywhere [Novalis]
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]
3. Truth / B. Truthmakers / 5. What Makes Truths / b. Objects make truths
15134 The truthmaker principle requires some specific named thing to make the difference [Williamson]
3. Truth / B. Truthmakers / 7. Making Modal Truths
15141 Truthmaker is incompatible with modal semantics of varying domains [Williamson]
15140 The converse Barcan formula will not allow contingent truths to have truthmakers [Williamson]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
15131 If metaphysical possibility is not a contingent matter, then S5 seems to suit it best [Williamson]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
15135 If the domain of propositional quantification is constant, the Barcan formulas hold [Williamson]
15139 Converse Barcan: could something fail to meet a condition, if everything meets that condition? [Williamson]
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 / G. Quantification / 1. Quantification
18492 Not all quantification is either objectual or substitutional [Williamson]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
15136 Substitutional quantification is metaphysical neutral, and equivalent to a disjunction of instances [Williamson]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
15138 Not all quantification is objectual or substitutional [Williamson]
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]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
15137 If 'fact' is a noun, can we name the fact that dogs bark 'Mary'? [Williamson]
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
15142 Our ability to count objects across possibilities favours the Barcan formulas [Williamson]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
19591 Desire for perfection is an illness, if it turns against what is imperfect [Novalis]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
15133 A thing can't be the only necessary existent, because its singleton set would be as well [Williamson]