Combining Texts

All the ideas for 'The Statesman', 'How to Define Theoretical Terms' and 'Set Theory'

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26 ideas

1. Philosophy / F. Analytic Philosophy / 2. Analysis by Division
16123 Whenever you perceive a community of things, you should also hunt out differences in the group [Plato]
2. Reason / D. Definition / 2. Aims of Definition
16125 To reveal a nature, divide down, and strip away what it has in common with other things [Plato]
16124 No one wants to define 'weaving' just for the sake of weaving [Plato]
15527 Defining terms either enables elimination, or shows that they don't require elimination [Lewis]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
13030 Extensionality: ∀x ∀y (∀z (z ∈ x ↔ z ∈ y) → x = y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
13032 Pairing: ∀x ∀y ∃z (x ∈ z ∧ y ∈ z) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / d. Axiom of Unions III
13033 Union: ∀F ∃A ∀Y ∀x (x ∈ Y ∧ Y ∈ F → x ∈ A) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
13037 Infinity: ∃x (0 ∈ x ∧ ∀y ∈ x (S(y) ∈ x) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
13038 Power Set: ∀x ∃y ∀z(z ⊂ x → z ∈ y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
13034 Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
13039 Foundation:∀x(∃y(y∈x) → ∃y(y∈x ∧ ¬∃z(z∈x ∧ z∈y))) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
13036 Choice: ∀A ∃R (R well-orders A) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / k. Axiom of Existence
13029 Set Existence: ∃x (x = x) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / n. Axiom of Comprehension
13031 Comprehension: ∃y ∀x (x ∈ y ↔ x ∈ z ∧ φ) [Kunen]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / o. Axiom of Constructibility V = L
13040 Constructibility: V = L (all sets are constructible) [Kunen]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
15530 A logically determinate name names the same thing in every possible world [Lewis]
12. Knowledge Sources / A. A Priori Knowledge / 3. Innate Knowledge / b. Recollection doctrine
5961 The soul gets its goodness from god, and its evil from previous existence. [Plato]
14. Science / B. Scientific Theories / 8. Ramsey Sentences
15531 The Ramsey sentence of a theory says that it has at least one realisation [Lewis]
15528 A Ramsey sentence just asserts that a theory can be realised, without saying by what [Lewis]
15526 There is a method for defining new scientific terms just using the terms we already understand [Lewis]
15529 It is better to have one realisation of a theory than many - but it may not always be possible [Lewis]
19. Language / F. Communication / 1. Rhetoric
283 The question of whether or not to persuade comes before the science of persuasion [Plato]
21. Aesthetics / A. Aesthetic Experience / 5. Natural Beauty
282 Non-physical beauty can only be shown clearly by speech [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / f. The Mean
281 The arts produce good and beautiful things by preserving the mean [Plato]
24. Political Theory / D. Ideologies / 5. Democracy / a. Nature of democracy
22559 Democracy is the worst of good constitutions, but the best of bad constitutions [Plato, by Aristotle]
28. God / A. Divine Nature / 2. Divine Nature
279 Only divine things can always stay the same, and bodies are not like that [Plato]