Combining Texts

All the ideas for 'Locke on Essences and Kinds', 'Human Flourishing, Ethics and Liberty' 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 / 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]
9. Objects / D. Essence of Objects / 13. Nominal Essence
If kinds depend only on what can be observed, many underlying essences might produce the same kind [Eagle]
Nominal essence are the observable properties of things [Eagle]
Nominal essence mistakenly gives equal weight to all underlying properties that produce appearances [Eagle]
22. Metaethics / C. The Good / 1. Goodness / d. Good as virtue
Basing ethics on flourishing makes it consequentialist, as actions are judged by contributing to it [Harman]
22. Metaethics / C. The Good / 2. Happiness / b. Eudaimonia
What counts as 'flourishing' must be relative to various sets of values [Harman]
26. Natural Theory / B. Natural Kinds / 4. Source of Kinds
Kinds are fixed by the essential properties of things - the properties that make it that kind of thing [Eagle]