Combining Texts

All the ideas for '26: Oracles in Decline', 'Scientific Attitude and Fallibilism' and 'Alfred Tarski: life and logic'

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21 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
10147 The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
10148 Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
10149 Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
10150 The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
10146 Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
10158 A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
10162 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
10160 Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
10159 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
10161 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
10156 'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
10155 Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
14775 Numbers are just names devised for counting [Peirce]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
14776 That two two-eyed people must have four eyes is a statement about numbers, not a fact [Peirce]
11. Knowledge Aims / B. Certain Knowledge / 3. Fallibilism
14770 Reasoning is based on statistical induction, so it can't achieve certainty or precision [Peirce]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
5958 The sun is always bright; it doesn't become bright when it emerges [Plutarch]
12. Knowledge Sources / A. A Priori Knowledge / 3. Innate Knowledge / a. Innate knowledge
14774 Innate truths are very uncertain and full of error, so they certainly have exceptions [Peirce]
12. Knowledge Sources / E. Direct Knowledge / 3. Inspiration
14773 A truth is hard for us to understand if it rests on nothing but inspiration [Peirce]
14772 If we decide an idea is inspired, we still can't be sure we have got the idea right [Peirce]
14771 Only reason can establish whether some deliverance of revelation really is inspired [Peirce]
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
14769 Only imagination can connect phenomena together in a rational way [Peirce]