Combining Texts

All the ideas for 'fragments/reports', 'On Referring' and 'Investigations in the Foundations of Set Theory I'

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24 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]
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]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
There are no rules for the exact logic of ordinary language, because that doesn't exist [Strawson,P]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
'The present King of France is bald' presupposes existence, rather than stating it [Strawson,P, by Grayling]
Russell asks when 'The King of France is wise' would be a true assertion [Strawson,P]
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 / 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]
19. Language / A. Nature of Meaning / 6. Meaning as Use
The meaning of an expression or sentence is general directions for its use, to refer or to assert [Strawson,P]
19. Language / B. Reference / 3. Direct Reference / c. Social reference
Reference is mainly a social phenomenon [Strawson,P, by Sainsbury]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
If an expression can refer to anything, it may still instrinsically refer, but relative to a context [Bach on Strawson,P]
19. Language / B. Reference / 5. Speaker's Reference
Expressions don't refer; people use expressions to refer [Strawson,P]
If an utterance fails to refer then it is a pseudo-use, though a speaker may think they assert something [Strawson,P]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]