Combining Texts

All the ideas for 'Euthydemus', 'Elements of Set Theory' and 'Many, but almost one'

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18 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]
13204 The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton]
13206 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
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 / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
15538 Semantic indecision explains vagueness (if we have precisifications to be undecided about) [Lewis]
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
304 Beautiful things must be different from beauty itself, but beauty itself must be present in each of them [Plato]
9. Objects / B. Unity of Objects / 3. Unity Problems / b. Cat and its tail
15537 If cats are vague, we deny that the many cats are one, or deny that the one cat is many [Lewis]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
15536 We have one cloud, but many possible boundaries and aggregates for it [Lewis]
11. Knowledge Aims / A. Knowledge / 1. Knowledge
16120 Knowing how to achieve immortality is pointless without the knowledge how to use immortality [Plato]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
303 Say how many teeth the other has, then count them. If you are right, we will trust your other claims [Plato]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
15539 Basic to pragmatics is taking a message in a way that makes sense of it [Lewis]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / d. Ethical theory
302 What knowledge is required to live well? [Plato]
22. Metaethics / C. The Good / 1. Goodness / e. Good as knowledge
301 Only knowledge of some sort is good [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / f. The Mean
305 Something which lies midway between two evils is better than either of them [Plato]