Combining Texts

All the ideas for 'Gödel's Proof', 'Model Theory' and 'Ontological Categories'

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23 ideas

2. Reason / D. Definition / 7. Contextual Definition
The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Since first-order languages are complete, |= and |- have the same meaning [Hodges,W]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
|= in model-theory means 'logical consequence' - it holds in all models [Hodges,W]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
We negate predicates but do not negate names [Westerhoff]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
|= should be read as 'is a model for' or 'satisfies' [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Model theory studies formal or natural language-interpretation using set-theory [Hodges,W]
A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W]
Models in model theory are structures, not sets of descriptions [Hodges,W]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
First-order logic can't discriminate between one infinite cardinal and another [Hodges,W]
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 / D. Essence of Objects / 5. Essence as Kind
Essential kinds may be too specific to provide ontological categories [Westerhoff]
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
The human intellect has not been, and cannot be, fully formalized [Nagel/Newman]