Combining Philosophers

All the ideas for Rescher,N/Oppenheim,P, Cynthia Macdonald and George Cantor

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82 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
Philosophy tries to explain how the actual is possible, given that it seems impossible [Macdonald,C]
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
'Did it for the sake of x' doesn't involve a sake, so how can ontological commitments be inferred? [Macdonald,C]
2. Reason / F. Fallacies / 5. Fallacy of Composition
Don't assume that a thing has all the properties of its parts [Macdonald,C]
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]
7. Existence / C. Structure of Existence / 2. Reduction
Reduce by bridge laws (plus property identities?), by elimination, or by reducing talk [Macdonald,C]
8. Modes of Existence / A. Relations / 2. Internal Relations
Relational properties are clearly not essential to substances [Macdonald,C]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
Being taller is an external relation, but properties and substances have internal relations [Macdonald,C]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Does the knowledge of each property require an infinity of accompanying knowledge? [Macdonald,C]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes are abstract (two can occupy the same place), but not universals (they have locations) [Macdonald,C]
Properties are sets of exactly resembling property-particulars [Macdonald,C]
Tropes are abstract particulars, not concrete particulars, so the theory is not nominalist [Macdonald,C]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
How do a group of resembling tropes all resemble one another in the same way? [Macdonald,C]
Trope Nominalism is the only nominalism to introduce new entities, inviting Ockham's Razor [Macdonald,C]
8. Modes of Existence / D. Universals / 2. Need for Universals
Numerical sameness is explained by theories of identity, but what explains qualitative identity? [Macdonald,C]
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
How can universals connect instances, if they are nothing like them? [Macdonald,C]
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Real Nominalism is only committed to concrete particulars, word-tokens, and (possibly) sets [Macdonald,C]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblance Nominalism cannot explain either new resemblances, or absence of resemblances [Macdonald,C]
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
A 'thing' cannot be in two places at once, and two things cannot be in the same place at once [Macdonald,C]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
We 'individuate' kinds of object, and 'identify' particular specimens [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Unlike bundles of properties, substances have an intrinsic unity [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
The bundle theory of substance implies the identity of indiscernibles [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
A phenomenalist cannot distinguish substance from attribute, so must accept the bundle view [Macdonald,C]
When we ascribe a property to a substance, the bundle theory will make that a tautology [Macdonald,C]
Substances persist through change, but the bundle theory says they can't [Macdonald,C]
A substance might be a sequence of bundles, rather than a single bundle [Macdonald,C]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
A statue and its matter have different persistence conditions, so they are not identical [Macdonald,C]
9. Objects / C. Structure of Objects / 7. Substratum
A substance is either a bundle of properties, or a bare substratum, or an essence [Macdonald,C]
Each substance contains a non-property, which is its substratum or bare particular [Macdonald,C]
The substratum theory explains the unity of substances, and their survival through change [Macdonald,C]
A substratum has the quality of being bare, and they are useless because indiscernible [Macdonald,C]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
At different times Leibniz articulated three different versions of his so-called Law [Macdonald,C]
The Identity of Indiscernibles is false, because it is not necessarily true [Macdonald,C]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
In continuity, what matters is not just the beginning and end states, but the process itself [Macdonald,C]
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]
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]