Combining Texts

All the ideas for 'Cratylus', 'Introduction to 'Self-Knowledge'' and 'works'

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67 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 / 1. Set Theory
Trying to represent curves, we study arbitrary functions, leading to the ordinals, which produces set theory [Cantor, by Lavine]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / c. Basic theorems of ST
Cantor's Theorem: for any set x, its power set P(x) has more members than x [Cantor, by Hart,WD]
Cantor proved that all sets have more subsets than they have members [Cantor, by Bostock]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
If a set is 'a many thought of as one', beginners should protest against singleton sets [Cantor, by Lewis]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / d. Infinite Sets
Cantor showed that supposed contradictions in infinity were just a lack of clarity [Cantor, by Potter]
The continuum is the powerset of the integers, which moves up a level [Cantor, by Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / d. Axiom of Unions III
The Axiom of Union dates from 1899, and seems fairly obvious [Cantor, by Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / b. Combinatorial sets
Cantor's sets were just collections, but Dedekind's were containers [Cantor, by Oliver/Smiley]
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 / K. Features of Logics / 8. Enumerability
There are infinite sets that are not enumerable [Cantor, by Smith,P]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / b. Cantor's paradox
Cantor's Paradox: the power set of the universe must be bigger than the universe, yet a subset of it [Cantor, by Hart,WD]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / e. Mirimanoff's paradox
The powerset of all the cardinal numbers is required to be greater than itself [Cantor, by Friend]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Cantor named the third realm between the finite and the Absolute the 'transfinite' [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Cantor proved the points on a plane are in one-to-one correspondence to the points on a line [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Cantor took the ordinal numbers to be primary [Cantor, by Tait]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
Cantor presented the totality of natural numbers as finite, not infinite [Cantor, by Mayberry]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Cantor introduced the distinction between cardinals and ordinals [Cantor, by Tait]
Cantor showed that ordinals are more basic than cardinals [Cantor, by Dummett]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / f. Cardinal numbers
A cardinal is an abstraction, from the nature of a set's elements, and from their order [Cantor]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Cantor tried to prove points on a line matched naturals or reals - but nothing in between [Cantor, by Lavine]
Cantor's diagonal argument proved you can't list all decimal numbers between 0 and 1 [Cantor, by Read]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
A real is associated with an infinite set of infinite Cauchy sequences of rationals [Cantor, by Lavine]
Irrational numbers are the limits of Cauchy sequences of rational numbers [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Irrationals and the Dedekind Cut implied infinite classes, but they seemed to have logical difficulties [Cantor, by Lavine]
It was Cantor's diagonal argument which revealed infinities greater than that of the real numbers [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Cantor proposes that there won't be a potential infinity if there is no actual infinity [Cantor, by Hart,WD]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
The naturals won't map onto the reals, so there are different sizes of infinity [Cantor, by George/Velleman]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro]
CH: An infinite set of reals corresponds 1-1 either to the naturals or to the reals [Cantor, by Koellner]
Cantor: there is no size between naturals and reals, or between a set and its power set [Cantor, by Hart,WD]
Cantor's Continuum Hypothesis says there is a gap between the natural and the real numbers [Cantor, by Horsten]
Continuum Hypothesis: there are no sets between N and P(N) [Cantor, by Wolf,RS]
Continuum Hypothesis: no cardinal greater than aleph-null but less than cardinality of the continuum [Cantor, by Chihara]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
Cantor extended ordinals into the transfinite, and they can thus measure infinite cardinalities [Cantor, by Maddy]
Cantor's theory concerns collections which can be counted, using the ordinals [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
Cardinality strictly concerns one-one correspondence, to test infinite sameness of size [Cantor, by Maddy]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
Property extensions outstrip objects, so shortage of objects caused the Caesar problem [Cantor, by Shapiro]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Pure mathematics is pure set theory [Cantor]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
Cantor says that maths originates only by abstraction from objects [Cantor, by Frege]
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]
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]
16. Persons / B. Nature of the Self / 7. Self and Body / a. Self needs body
If we have a pain, we are strongly aware of the bodily self [Cassam]
16. Persons / C. Self-Awareness / 1. Introspection
Knowledge of thoughts covers both their existence and their contents [Cassam]
16. Persons / C. Self-Awareness / 2. Knowing the Self
Outer senses are as important as introspection in the acquisition of self-knowledge [Cassam]
Is there a mode of self-awareness that isn't perception, and could it give self-knowledge? [Cassam]
Neither self-consciousness nor self-reference require self-knowledge [Cassam]
16. Persons / C. Self-Awareness / 3. Limits of Introspection
We can't introspect ourselves as objects, because that would involve possible error [Cassam]
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
Infinities expand the bounds of the conceivable; we explore concepts to explore conceivability [Cantor, by Friend]
18. Thought / E. Abstraction / 2. Abstracta by Selection
Cantor says (vaguely) that we abstract numbers from equal sized sets [Hart,WD on Cantor]
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 / C. Space / 3. Points in Space
Cantor proved that three dimensions have the same number of points as one dimension [Cantor, by Clegg]
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
Only God is absolutely infinite [Cantor, by Hart,WD]
Even the gods love play [Plato]