Combining Texts

All the ideas for 'fragments/reports', 'Explanation: the state of play' and 'works'

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68 ideas

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 / 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 / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
Things get smaller without end [Anaxagoras]
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 / A. Nature of Existence / 1. Nature of Existence
Nothing is created or destroyed; there is only mixing and separation [Anaxagoras]
7. Existence / A. Nature of Existence / 3. Being / f. Primary being
Anaxagoras's concept of supreme Mind has a simple First and a multiple One [Anaxagoras, by Plotinus]
7. Existence / C. Structure of Existence / 6. Fundamentals / a. Fundamental reality
Basic is the potentially perceptible, then comes the contrary qualities, and finally the 'elements' [Anaxagoras]
12. Knowledge Sources / B. Perception / 1. Perception
Snow is not white, and doesn't even appear white, because it is made of black water [Anaxagoras, by Cicero]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
The senses are too feeble to determine the truth [Anaxagoras]
13. Knowledge Criteria / D. Scepticism / 2. Types of Scepticism
We reveal unreliability in the senses when we cannot discriminate a slow change of colour [Anaxagoras, by Sext.Empiricus]
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
Audience-relative explanation, or metaphysical explanation based on information? [Stanford]
Explanation is for curiosity, control, understanding, to make meaningful, or to give authority [Stanford]
14. Science / D. Explanation / 2. Types of Explanation / j. Explanations by reduction
We can explain by showing constitution, as well as showing causes [Stanford]
15. Nature of Minds / A. Nature of Mind / 1. Mind / a. Mind
Nous is unlimited, self-ruling and pure; it is the finest thing, with great discernment and strength [Anaxagoras]
15. Nature of Minds / A. Nature of Mind / 1. Mind / c. Features of mind
Mind is self-ruling, pure, ordering and ubiquitous [Anaxagoras, by Plato]
16. Persons / F. Free Will / 1. Nature of Free Will
Anaxagoras says mind remains pure, and so is not affected by what it changes [Anaxagoras, by Aristotle]
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 / 3. Virtues / g. Contemplation
Anaxagoras said a person would choose to be born to contemplate the ordered heavens [Anaxagoras]
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / a. Final purpose
For Anaxagoras the Good Mind has no opposite, and causes all movement, for a higher reason [Anaxagoras, by Aristotle]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / a. Greek matter
Mind creates the world from a mixture of pure substances [Anaxagoras, by ]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / c. Ultimate substances
Anaxagoras said that the number of principles was infinite [Anaxagoras, by Aristotle]
The ultimate constituents of reality are the homoeomeries [Anaxagoras, by Vlastos]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
Anaxagoreans regard the homoeomeries as elements, which compose earth, air, fire and water [Anaxagoras, by Aristotle]
26. Natural Theory / C. Causation / 1. Causation
Anaxagoras says mind produces order and causes everything [Anaxagoras, by 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 / 1. Biology
Germs contain microscopic organs, which become visible as they grow [Anaxagoras]
28. God / A. Divine Nature / 1. God
When things were unified, Mind set them in order [Anaxagoras]
Anaxagoras was the first to say that the universe is directed by an intelligence [Anaxagoras, by Cicero]
28. God / A. Divine Nature / 2. Divine Nature
Only God is absolutely infinite [Cantor, by Hart,WD]
28. God / B. Proving God / 3. Proofs of Evidence / b. Teleological Proof
Past, present and future, and the movements of the heavens, were arranged by Mind [Anaxagoras]
28. God / C. Attitudes to God / 5. Atheism
Anaxagoras was charged with impiety for calling the sun a lump of stone [Anaxagoras, by Plutarch]
Anaxagoras was the first recorded atheist [Anaxagoras, by Watson]