Combining Texts

All the ideas for 'On What Grounds What', 'Continuity and Irrational Numbers' and 'Investigations in the Foundations of Set Theory I'

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30 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J]
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
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
We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J]
2. Reason / D. Definition / 8. Impredicative Definition
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
We take set theory as given, and retain everything valuable, while avoiding contradictions [Zermelo]
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
ZFC: Existence, Extension, Specification, Pairing, Unions, Powers, Infinity, Choice [Zermelo, by Clegg]
Zermelo published his axioms in 1908, to secure a controversial proof [Zermelo, by Maddy]
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
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
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
The Axiom of Separation requires set generation up to one step back from contradiction [Zermelo, by Maddy]
Not every predicate has an extension, but Separation picks the members that satisfy a predicate [Zermelo, by Hart,WD]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals [Zermelo, by Hart,WD]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
We want the essence of continuity, by showing its origin in arithmetic [Dedekind]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
A cut between rational numbers creates and defines an irrational number [Dedekind]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / f. Arithmetic
Arithmetic is just the consequence of counting, which is the successor operation [Dedekind]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
If x changes by less and less, it must approach a limit [Dedekind]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
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
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
Different versions of set theory result in different underlying structures for numbers [Zermelo, by Brown,JR]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
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
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
Supervenience is just modal correlation [Schaffer,J]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J]
7. Existence / E. Categories / 4. Category Realism
Maybe categories are just the different ways that things depend on basic substances [Schaffer,J]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J]
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
Belief in impossible worlds may require dialetheism [Schaffer,J]
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
'Moorean certainties' are more credible than any sceptical argument [Schaffer,J]