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All the ideas for 'works', 'Definitions' and 'Elements of Set Theory'

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22 ideas

2. Reason / D. Definition / 1. Definitions
Definitions usually have a term, a 'definiendum' containing the term, and a defining 'definiens' [Gupta]
Notable definitions have been of piety (Plato), God (Anselm), number (Frege), and truth (Tarski) [Gupta]
2. Reason / D. Definition / 2. Aims of Definition
A definition needs to apply to the same object across possible worlds [Gupta]
The 'revision theory' says that definitions are rules for improving output [Gupta]
2. Reason / D. Definition / 3. Types of Definition
Traditional definitions are general identities, which are sentential and reductive [Gupta]
Traditional definitions need: same category, mention of the term, and conservativeness and eliminability [Gupta]
A definition can be 'extensionally', 'intensionally' or 'sense' adequate [Gupta]
2. Reason / D. Definition / 4. Real Definition
Chemists aim at real definition of things; lexicographers aim at nominal definition of usage [Gupta]
2. Reason / D. Definition / 6. Definition by Essence
If definitions aim at different ideals, then defining essence is not a unitary activity [Gupta]
2. Reason / D. Definition / 10. Stipulative Definition
Stipulative definition assigns meaning to a term, ignoring prior meanings [Gupta]
2. Reason / D. Definition / 11. Ostensive Definition
Ostensive definitions look simple, but are complex and barely explicable [Gupta]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton]
The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton]
A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton]
The empty set may look pointless, but many sets can be constructed from it [Enderton]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
The singleton is defined using the pairing axiom (as {x,x}) [Enderton]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
We can only define functions if Choice tells us which items are involved [Enderton]
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
The ordered pair <x,y> is defined as the set {{x},{x,y}}, capturing function, not meaning [Gupta]
29. Religion / B. Monotheistic Religion / 4. Christianity / d. Heresy
Philosophers are the forefathers of heretics [Tertullian]
29. Religion / D. Religious Issues / 1. Religious Commitment / e. Fideism
I believe because it is absurd [Tertullian]