Combining Texts

All the ideas for 'Cratylus', 'The History of Animals' and 'Alfred Tarski: life and logic'

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34 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Wisdom is called 'beautiful', because it performs fine works [Plato]
1. Philosophy / A. Wisdom / 2. Wise People
Good people are no different from wise ones [Plato]
2. Reason / C. Styles of Reason / 1. Dialectic
A dialectician is someone who knows how to ask and to answer questions [Plato]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Truths say of what is that it is, falsehoods say of what is that it is not [Plato]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
A name is a sort of tool [Plato]
A name-giver might misname something, then force other names to conform to it [Plato]
Things must be known before they are named, so it can't be the names that give us knowledge [Plato]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
Anyone who knows a thing's name also knows the thing [Plato]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
7. Existence / B. Change in Existence / 1. Nature of Change
How can beauty have identity if it changes? [Plato]
7. Existence / E. Categories / 2. Categorisation
We only succeed in cutting if we use appropriate tools, not if we approach it randomly [Plato]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
Doesn't each thing have an essence, just as it has other qualities? [Plato]
9. Objects / D. Essence of Objects / 3. Individual Essences
Things don't have every attribute, and essence isn't private, so each thing has an essence [Plato]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Is the being or essence of each thing private to each person? [Plato]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
If we made a perfect duplicate of Cratylus, there would be two Cratyluses [Plato]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
There can't be any knowledge if things are constantly changing [Plato]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
Aristotelian explanation by essence may need to draw on knowledge of other essences [Aristotle, by Koslicki]
15. Nature of Minds / A. Nature of Mind / 2. Psuche
Soul causes the body to live, and gives it power to breathe and to be revitalized [Plato]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
'Arete' signifies lack of complexity and a free-flowing soul [Plato]
27. Natural Reality / G. Biology / 2. Life
Plants have far less life than animals, but more life than other corporeal entities [Aristotle]
27. Natural Reality / G. Biology / 3. Evolution
There is a gradual proceeding from the inanimate to animals, with no clear borderlines [Aristotle]
27. Natural Reality / G. Biology / 5. Species
The natural offspring of a lion is called a 'lion' (but what about the offspring of a king?) [Plato]
28. God / A. Divine Nature / 2. Divine Nature
Even the gods love play [Plato]