Combining Texts

All the ideas for 'Classical Cosmology (frags)', 'The Analysis of Matter' and 'Alfred Tarski: life and logic'

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18 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
7. Existence / B. Change in Existence / 4. Events / b. Events as primitive
In 1927, Russell analysed force and matter in terms of events [Russell, by Grayling]
9. Objects / A. Existence of Objects / 1. Physical Objects
A perceived physical object is events grouped around a centre [Russell]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
An object produces the same percepts with or without a substance, so that is irrelevant to science [Russell]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Russell rejected phenomenalism because it couldn't account for causal relations [Russell, by Grayling]
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
At first matter is basic and known by sense-data; later Russell says matter is constructed [Russell, by Linsky,B]
27. Natural Reality / E. Cosmology / 1. Cosmology
Is the cosmos open or closed, mechanical or teleological, alive or inanimate, and created or eternal? [Robinson,TM, by PG]