Combining Texts

All the ideas for 'Deflationary Metaontology of Thomasson', 'Elements of Set Theory' and 'Ontological Categories'

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24 ideas

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]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
We negate predicates but do not negate names [Westerhoff]
7. Existence / E. Categories / 1. Categories
Categories can be ordered by both containment and generality [Westerhoff]
How far down before we are too specialised to have a category? [Westerhoff]
Maybe objects in the same category have the same criteria of identity [Westerhoff]
Categories are base-sets which are used to construct states of affairs [Westerhoff]
Categories are held to explain why some substitutions give falsehood, and others meaninglessness [Westerhoff]
Categories systematize our intuitions about generality, substitutability, and identity [Westerhoff]
Categories as generalities don't give a criterion for a low-level cut-off point [Westerhoff]
7. Existence / E. Categories / 2. Categorisation
The aim is that everything should belong in some ontological category or other [Westerhoff]
7. Existence / E. Categories / 3. Proposed Categories
All systems have properties and relations, and most have individuals, abstracta, sets and events [Westerhoff]
7. Existence / E. Categories / 5. Category Anti-Realism
Ontological categories are like formal axioms, not unique and with necessary membership [Westerhoff]
Categories merely systematise, and are not intrinsic to objects [Westerhoff]
A thing's ontological category depends on what else exists, so it is contingent [Westerhoff]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Essential kinds may be too specific to provide ontological categories [Westerhoff]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J]