Combining Texts

All the ideas for 'Infinity: Quest to Think the Unthinkable', 'Meaning and Necessity' and 'Logic and Epistemology of Causal Relations'

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28 ideas

4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
A set is 'well-ordered' if every subset has a first element [Clegg]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / d. Infinite Sets
Set theory made a closer study of infinity possible [Clegg]
Any set can always generate a larger set - its powerset, of subsets [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
Extensionality: Two sets are equal if and only if they have the same elements [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
Pairing: For any two sets there exists a set to which they both belong [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / d. Axiom of Unions III
Unions: There is a set of all the elements which belong to at least one set in a collection [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
Infinity: There exists a set of the empty set and the successor of each element [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
Powers: All the subsets of a given set form their own new powerset [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Choice: For every set a mechanism will choose one member of any non-empty subset [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / k. Axiom of Existence
Axiom of Existence: there exists at least one set [Clegg]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / l. Axiom of Specification
Specification: a condition applied to a set will always produce a new set [Clegg]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Mathematics can be 'pure' (unapplied), 'real' (physically grounded); or 'applied' (just applicable) [Clegg]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Beyond infinity cardinals and ordinals can come apart [Clegg]
An ordinal number is defined by the set that comes before it [Clegg]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Transcendental numbers can't be fitted to finite equations [Clegg]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / k. Imaginary numbers
By adding an axis of imaginary numbers, we get the useful 'number plane' instead of number line [Clegg]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / l. Zero
Either lack of zero made early mathematics geometrical, or the geometrical approach made zero meaningless [Clegg]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Cantor's account of infinities has the shaky foundation of irrational numbers [Clegg]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
The Continuum Hypothesis is independent of the axioms of set theory [Clegg]
The 'continuum hypothesis' says aleph-one is the cardinality of the reals [Clegg]
10. Modality / B. Possibility / 1. Possibility
What is true used to be possible, but it may no longer be so [Wright,GHv]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
The intension of a sentence is the set of all possible worlds in which it is true [Carnap, by Kaplan]
26. Natural Theory / C. Causation / 5. Direction of causation
p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv]
We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv]
26. Natural Theory / C. Causation / 8. Particular Causation / a. Observation of causation
The very notion of a cause depends on agency and action [Wright,GHv]
We give regularities a causal character by subjecting them to experiment [Wright,GHv]
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv]
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv]