Combining Texts

All the ideas for 'Identity and Spatio-Temporal Continuity', 'works' and 'Elements of Set Theory'

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14 ideas

2. Reason / B. Laws of Thought / 6. Ockham's Razor
Do not multiply entities beyond necessity [William of Ockham]
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]
8. Modes of Existence / D. Universals / 5. Universals as Concepts
Species and genera are individual concepts which naturally signify many individuals [William of Ockham]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
'Ultimate sortals' cannot explain ontological categories [Westerhoff on Wiggins]
27. Natural Reality / D. Time / 1. Nature of Time / i. Denying time
The past has ceased to exist, and the future does not yet exist, so time does not exist [William of Ockham]
28. God / A. Divine Nature / 6. Divine Morality / d. God decrees morality
William of Ockham is the main spokesman for God's commands being the source of morality [William of Ockham]
29. Religion / B. Monotheistic Religion / 4. Christianity / c. Angels
Even an angel must have some location [William of Ockham, by Pasnau]