Combining Texts

All the ideas for 'fragments/reports', 'Elements of Set Theory' and 'Essential Attribution'

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20 ideas

4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
13201 ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton]
13206 A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton]
13204 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
13200 Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton]
13199 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
13203 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
13202 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
13205 We can only define functions if Choice tells us which items are involved [Enderton]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
18933 Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
11181 Aristotelian essentialism involves a 'natural' or 'causal' interpretation of modal operators [Marcus (Barcan)]
11184 Aristotelian essentialism is about shared properties, individuating essentialism about distinctive properties [Marcus (Barcan)]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
11180 Essentialist sentences are not theorems of modal logic, and can even be false [Marcus (Barcan)]
11186 'Essentially' won't replace 'necessarily' for vacuous properties like snub-nosed or self-identical [Marcus (Barcan)]
11185 'Is essentially' has a different meaning from 'is necessarily', as they often cannot be substituted [Marcus (Barcan)]
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
11182 If essences are objects with only essential properties, they are elusive in possible worlds [Marcus (Barcan)]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
11183 The use of possible worlds is to sort properties (not to individuate objects) [Marcus (Barcan)]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
11187 In possible worlds, names are just neutral unvarying pegs for truths and predicates [Marcus (Barcan)]
19. Language / F. Communication / 1. Rhetoric
9866 Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]
5864 Destroy seriousness with laughter, and laughter with seriousness [Gorgias]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
11189 Dispositional essences are special, as if an object loses them they cease to exist [Marcus (Barcan)]