Combining Philosophers

All the ideas for Porphyry, George Cantor and Stephen Davies

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95 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / b. Philosophy as transcendent
Philosophy has its own mode of death, by separating soul from body [Porphyry]
1. Philosophy / F. Analytic Philosophy / 3. Analysis of Preconditions
'Necessary' conditions are requirements, and 'sufficient' conditions are guarantees [Davies,S]
2. Reason / D. Definition / 1. Definitions
A definition of a thing gives all the requirements which add up to a guarantee of it [Davies,S]
2. Reason / D. Definition / 13. Against Definition
Feminists warn that ideologies use timeless objective definitions as a tool of repression [Davies,S]
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]
Cantor developed sets from a progression into infinity by addition, multiplication and exponentiation [Cantor, by Lavine]
A set is a collection into a whole of distinct objects of our intuition or thought [Cantor]
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 / a. Axioms for sets
Cantor gives informal versions of ZF axioms as ways of getting from one set to another [Cantor, by Lake]
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 / 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]
Ordinals are generated by endless succession, followed by a limit ordinal [Cantor, by Lavine]
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]
Cantor needed Power Set for the reals, but then couldn't count the new collections [Cantor, by Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
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]
The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro]
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's theory concerns collections which can be counted, using the ordinals [Cantor, by Lavine]
Cantor extended ordinals into the transfinite, and they can thus measure infinite cardinalities [Cantor, by Maddy]
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 / c. Fregean numbers
The 'extension of a concept' in general may be quantitatively completely indeterminate [Cantor]
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]
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
The presence of the incorporeal is only known by certain kinds of disposition [Porphyry]
8. Modes of Existence / D. Universals / 1. Universals
Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry]
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
Diversity arises from the power of unity [Porphyry]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Memory is not conserved images, but reproduction of previous thought [Porphyry]
15. Nature of Minds / A. Nature of Mind / 1. Mind / c. Features of mind
Intelligence is aware of itself, so the intelligence is both the thinker and the thought [Porphyry]
15. Nature of Minds / A. Nature of Mind / 1. Mind / d. Location of mind
The soul is everywhere and nowhere in the body, and must be its cause [Porphyry]
16. Persons / C. Self-Awareness / 2. Knowing the Self
Successful introspection reveals the substrate along with the object of thought [Porphyry]
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
The soul is bound to matter by the force of its own disposition [Porphyry]
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]
We form the image of a cardinal number by a double abstraction, from the elements and from their order [Cantor]
21. Aesthetics / A. Aesthetic Experience / 2. Aesthetic Attitude
Aesthetic experience involves perception, but also imagination and understanding [Davies,S]
21. Aesthetics / A. Aesthetic Experience / 3. Taste
The faculty of 'taste' was posited to explain why only some people had aesthetic appreciation [Davies,S]
21. Aesthetics / A. Aesthetic Experience / 6. The Sublime
The sublime is negative in awareness of insignificance, and positive in showing understanding [Davies,S]
21. Aesthetics / B. Nature of Art / 1. Defining Art
The idea that art forms are linked into a single concept began in the 1740s [Davies,S]
Defining art as representation or expression or form were all undermined by the avant-garde [Davies,S]
'Aesthetic functionalism' says art is what is intended to create aesthetic experiences [Davies,S]
21. Aesthetics / B. Nature of Art / 4. Art as Expression
Music may be expressive by being 'associated' with other emotional words or events [Davies,S]
It seems unlikely that sad music expresses a composer's sadness; it takes ages to write [Davies,S]
21. Aesthetics / B. Nature of Art / 6. Art as Institution
The 'institutional' theory says art is just something appropriately placed in the 'artworld' [Davies,S]
21. Aesthetics / B. Nature of Art / 8. The Arts / a. Music
Music is too definite to be put into words (not too indefinite!) [Davies,S]
21. Aesthetics / C. Artistic Issues / 1. Artistic Intentions
The title of a painting can be vital, and the artist decrees who the portrait represents [Davies,S]
We must know what the work is meant to be, to evaluate the artist's achievement [Davies,S]
Intentionalism says either meaning just is intention, or ('moderate') meaning is successful intention [Davies,S]
The meaning is given by the audience's best guess at the author's intentions [Davies,S]
21. Aesthetics / C. Artistic Issues / 2. Copies of Art
If we could perfectly clone the Mona Lisa, the original would still be special [Davies,S]
Art that is multiply instanced may require at least one instance [Davies,S]
21. Aesthetics / C. Artistic Issues / 4. Emotion in Art
Music isn't just sad because it makes the listener feel sad [Davies,S]
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
If the depiction of evil is glorified, that is an artistic flaw [Davies,S]
It is an artistic defect if excessive moral outrage distorts the story, and narrows our sympathies [Davies,S]
A work which seeks approval for immorality, but alienates the audience, is a failure [Davies,S]
Immorality may or may not be an artistic defect [Davies,S]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Justice is each person fulfilling his function [Porphyry]
22. Metaethics / B. Value / 2. Values / g. Love
We should avoid the pleasures of love, or at least, should not enact our dreams [Porphyry]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Civil virtues make us behave benevolently, and thereby unite citizens [Porphyry]
Civil virtues control the passions, and make us conform to our nature [Porphyry]
Purificatory virtues detach the soul completely from the passions [Porphyry]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
There are practical, purificatory, contemplative, and exemplary virtues [Porphyry]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Unified real existence is neither great nor small, though greatness and smallness participate in it [Porphyry]
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 / D. Time / 1. Nature of Time / c. Idealist time
Time is the circular movement of the soul [Porphyry]
27. Natural Reality / D. Time / 1. Nature of Time / e. Eventless time
Some think time is seen at rest, as well as in movement [Porphyry]
28. God / A. Divine Nature / 2. Divine Nature
God is nowhere, and hence everywhere [Porphyry]
Only God is absolutely infinite [Cantor, by Hart,WD]
28. God / C. Attitudes to God / 2. Pantheism
Everything existing proceeds from divinity, and is within divinity [Porphyry]
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
Nature binds or detaches body to soul, but soul itself joins and detaches soul from body [Porphyry]
Individual souls are all connected, though distinct, and without dividing universal Soul [Porphyry]