Combining Texts

All the ideas for 'Foundations of Geometry', 'Aboutness' and 'Investigations in the Foundations of Set Theory I'

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32 ideas

2. Reason / D. Definition / 8. Impredicative Definition
Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Zermelo, by Lavine]
3. Truth / A. Truth Problems / 5. Truth Bearers
A statement S is 'partly true' if it has some wholly true parts [Yablo]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
An 'enthymeme' is an argument with an indispensable unstated assumption [Yablo]
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
Not every predicate has an extension, but Separation picks the members that satisfy a predicate [Zermelo, by Hart,WD]
The Axiom of Separation requires set generation up to one step back from contradiction [Zermelo, by Maddy]
4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology
y is only a proper part of x if there is a z which 'makes up the difference' between them [Yablo]
5. Theory of Logic / F. Referring in Logic / 1. Naming / e. Empty names
'Pegasus doesn't exist' is false without Pegasus, yet the absence of Pegasus is its truthmaker [Yablo]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Hilbert aimed to eliminate number from geometry [Hilbert, 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 / B. Foundations for Mathematics / 3. Axioms for Geometry
Euclid axioms concerns possibilities of construction, but Hilbert's assert the existence of objects [Hilbert, by Chihara]
Hilbert's formalisation revealed implicit congruence axioms in Euclid [Hilbert, by Horsten/Pettigrew]
Hilbert's geometry is interesting because it captures Euclid without using real numbers [Hilbert, by Field,H]
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 / 3. Mathematical Nominalism
A nominalist can assert statements about mathematical objects, as being partly true [Yablo]
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
Parthood lacks the restriction of kind which most relations have [Yablo]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / b. Gettier problem
Gettier says you don't know if you are confused about how it is true [Yablo]
14. Science / B. Scientific Theories / 2. Aim of Science
A theory need not be true to be good; it should just be true about its physical aspects [Yablo]
14. Science / C. Induction / 5. Paradoxes of Induction / b. Raven paradox
If sentences point to different evidence, they must have different subject-matter [Yablo]
Most people say nonblack nonravens do confirm 'all ravens are black', but only a tiny bit [Yablo]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
Sentence-meaning is the truth-conditions - plus factors responsible for them [Yablo]
19. Language / C. Assigning Meanings / 4. Compositionality
The content of an assertion can be quite different from compositional content [Yablo]
19. Language / C. Assigning Meanings / 6. Truth-Conditions Semantics
Truth-conditions as subject-matter has problems of relevance, short cut, and reversal [Yablo]
19. Language / F. Communication / 3. Denial
Not-A is too strong to just erase an improper assertion, because it actually reverses A [Yablo]