Combining Texts

All the ideas for 'On the Natural Faculties', 'Fact, Fiction and Forecast (4th ed)' 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
The Axiom of Choice is consistent with the other axioms of set theory [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]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
5. Theory of Logic / C. Ontology of Logic / 4. Logic by Convention
If the result is bad, we change the rule; if we like the rule, we reject the result [Goodman]
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 Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
Löwenheim-Skolem says if the sentences are countable, so is the model [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]
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions seem more ethereal than behaviour; a non-occult account of them would be nice [Goodman]
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
Goodman argued that the confirmation relation can never be formalised [Goodman, by Horsten/Pettigrew]
Goodman showed that every sound inductive argument has an unsound one of the same form [Goodman, by Putnam]
15. Nature of Minds / C. Capacities of Minds / 1. Faculties
We just use the word 'faculty' when we don't know the psychological cause [Galen]
26. Natural Theory / D. Laws of Nature / 3. Laws and Generalities
We don't use laws to make predictions, we call things laws if we make predictions with them [Goodman]