Combining Texts

All the ideas for 'The Logic of Boundaryless Concepts', 'Elements of Set Theory' and 'De Re and De Dicto'

expand these ideas     |    start again     |     specify just one area for these texts


18 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]
A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton]
The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [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 / A. Overview of Logic / 3. Value of Logic
Logic guides thinking, but it isn't a substitute for it [Rumfitt]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
Maybe proper names involve essentialism [Plantinga]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Could I name all of the real numbers in one fell swoop? Call them all 'Charley'? [Plantinga]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
Surely self-identity is essential to Socrates? [Plantinga]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
9. Objects / D. Essence of Objects / 9. Essence and Properties
An object has a property essentially if it couldn't conceivably have lacked it [Plantinga]
10. Modality / A. Necessity / 4. De re / De dicto modality
Can we find an appropriate 'de dicto' paraphrase for any 'de re' proposition? [Plantinga]
Expressing modality about a statement is 'de dicto'; expressing it of property-possession is 'de re' [Plantinga]
'De dicto' true and 'de re' false is possible, and so is 'de dicto' false and 'de re' true [Plantinga]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
What Socrates could have been, and could have become, are different? [Plantinga]