Combining Texts

All the ideas for 'How the Laws of Physics Lie', 'The Theory of Transfinite Numbers' and 'Elements of Set Theory'

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27 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
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 / b. Terminology of ST
∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton]
A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton]
The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton]
The empty set may look pointless, but many sets can be constructed from it [Enderton]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
The singleton is defined using the pairing axiom (as {x,x}) [Enderton]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
We can only define functions if Choice tells us which items are involved [Enderton]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Cantor needed Power Set for the reals, but then couldn't count the new collections [Cantor, by Lavine]
7. Existence / E. Categories / 4. Category Realism
Causality indicates which properties are real [Cartwright,N]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
Two main types of explanation are by causes, or by citing a theoretical framework [Cartwright,N]
14. Science / D. Explanation / 2. Types of Explanation / c. Explanations by coherence
An explanation is a model that fits a theory and predicts the phenomenological laws [Cartwright,N]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Laws get the facts wrong, and explanation rests on improvements and qualifications of laws [Cartwright,N]
Laws apply to separate domains, but real explanations apply to intersecting domains [Cartwright,N]
The covering law view assumes that each phenomenon has a 'right' explanation [Cartwright,N]
Covering-law explanation lets us explain storms by falling barometers [Cartwright,N]
I disagree with the covering-law view that there is a law to cover every single case [Cartwright,N]
You can't explain one quail's behaviour by just saying that all quails do it [Cartwright,N]
14. Science / D. Explanation / 3. Best Explanation / c. Against best explanation
In science, best explanations have regularly turned out to be false [Cartwright,N]
26. Natural Theory / C. Causation / 8. Particular Causation / e. Probabilistic causation
A cause won't increase the effect frequency if other causes keep interfering [Cartwright,N]
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
There are fundamental explanatory laws (false!), and phenomenological laws (regularities) [Cartwright,N, by Bird]
Laws of appearances are 'phenomenological'; laws of reality are 'theoretical' [Cartwright,N]
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
Good organisation may not be true, and the truth may not organise very much [Cartwright,N]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
There are few laws for when one theory meets another [Cartwright,N]
To get from facts to equations, we need a prepared descriptions suited to mathematics [Cartwright,N]
Simple laws have quite different outcomes when they act in combinations [Cartwright,N]