Combining Philosophers

All the ideas for Boethius, Richard Cartwright and George Cantor

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92 ideas

1. Philosophy / D. Nature of Philosophy / 1. Philosophy
Philosophers working like teams of scientists is absurd, yet isolation is hard [Cartwright,R]
2. Reason / A. Nature of Reason / 6. Coherence
A false proposition isn't truer because it is part of a coherent system [Cartwright,R]
3. Truth / A. Truth Problems / 5. Truth Bearers
Are the truth-bearers sentences, utterances, ideas, beliefs, judgements, propositions or statements? [Cartwright,R]
Logicians take sentences to be truth-bearers for rigour, rather than for philosophical reasons [Cartwright,R]
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
The continuum is the powerset of the integers, which moves up a level [Cantor, by Clegg]
Cantor showed that supposed contradictions in infinity were just a lack of clarity [Cantor, by Potter]
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]
The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro]
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'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]
7. Existence / E. Categories / 1. Categories
There are two sorts of category - referring to things, and to circumstances of things [Boethius]
8. Modes of Existence / B. Properties / 11. Properties as Sets
While no two classes coincide in membership, there are distinct but coextensive attributes [Cartwright,R]
8. Modes of Existence / D. Universals / 5. Universals as Concepts
If universals are not separate, we can isolate them by abstraction [Boethius, by Panaccio]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
We can call the quality of Plato 'Platonity', and say it is a quality which only he possesses [Boethius]
9. Objects / B. Unity of Objects / 3. Unity Problems / a. Scattered objects
Clearly a pipe can survive being taken apart [Cartwright,R]
Bodies don't becomes scattered by losing small or minor parts [Cartwright,R]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
Essentialism says some of a thing's properties are necessary, and could not be absent [Cartwright,R]
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
The difficulty in essentialism is deciding the grounds for rating an attribute as essential [Cartwright,R]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essentialism is said to be unintelligible, because relative, if necessary truths are all analytic [Cartwright,R]
9. Objects / F. Identity among Objects / 3. Relative Identity
An act of ostension doesn't seem to need a 'sort' of thing, even of a very broad kind [Cartwright,R]
9. Objects / F. Identity among Objects / 4. Type Identity
A token isn't a unique occurrence, as the case of a word or a number shows [Cartwright,R]
11. Knowledge Aims / A. Knowledge / 2. Understanding
Reasoning relates to understanding as time does to eternity [Boethius, by Sorabji]
16. Persons / F. Free Will / 1. Nature of Free Will
Knowledge of present events doesn't make them necessary, so future events are no different [Boethius]
16. Persons / F. Free Will / 2. Sources of Free Will
Rational natures require free will, in order to have power of judgement [Boethius]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
God's universal foreknowledge seems opposed to free will [Boethius]
Does foreknowledge cause necessity, or necessity cause foreknowledge? [Boethius]
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]
19. Language / A. Nature of Meaning / 1. Meaning
People don't assert the meaning of the words they utter [Cartwright,R]
For any statement, there is no one meaning which any sentence asserting it must have [Cartwright,R]
19. Language / D. Propositions / 1. Propositions
We can pull apart assertion from utterance, and the action, the event and the subject-matter for each [Cartwright,R]
'It's raining' makes a different assertion on different occasions, but its meaning remains the same [Cartwright,R]
19. Language / D. Propositions / 4. Mental Propositions
We can attribute 'true' and 'false' to whatever it was that was said [Cartwright,R]
To assert that p, it is neither necessary nor sufficient to utter some particular words [Cartwright,R]
19. Language / F. Communication / 2. Assertion
Assertions, unlike sentence meanings, can be accurate, probable, exaggerated, false.... [Cartwright,R]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
The wicked want goodness, so they would not be wicked if they obtained it [Boethius]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
Rewards and punishments are not deserved if they don't arise from free movement of the mind [Boethius]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
When people fall into wickedness they lose their human nature [Boethius]
22. Metaethics / C. The Good / 2. Happiness / a. Nature of happiness
Happiness is a good which once obtained leaves nothing more to be desired [Boethius]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
The bad seek the good through desire, but the good through virtue, which is more natural [Boethius]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / j. Unity of virtue
Varied aims cannot be good because they differ, but only become good when they unify [Boethius]
25. Social Practice / A. Freedoms / 2. Freedom of belief
You can't control someone's free mind, only their body and possessions [Boethius]
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]
28. God / A. Divine Nature / 2. Divine Nature
Only God is absolutely infinite [Cantor, by Hart,WD]
28. God / A. Divine Nature / 5. God and Time
Divine eternity is the all-at-once and complete possession of unending life [Boethius]
28. God / A. Divine Nature / 6. Divine Morality / a. Divine morality
Where does evil come from if there is a god; where does good come from if there isn't? [Boethius]
28. God / A. Divine Nature / 6. Divine Morality / c. God is the good
God is the supreme good, so no source of goodness could take precedence over God [Boethius]
God is the good [Boethius]
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
The power through which creation remains in existence and motion I call 'God' [Boethius]
28. God / B. Proving God / 3. Proofs of Evidence / b. Teleological Proof
The regular events of this life could never be due to chance [Boethius]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
The reward of the good is to become gods [Boethius]
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
God can do anything, but he cannot do evil, so evil must be nothing [Boethius]
If you could see the plan of Providence, you would not think there was evil anywhere [Boethius]