Combining Texts

All the ideas for 'Natural Kinds and Biological Realism', 'Elements of Set Theory' and 'The Doctrine of Necessity Examined'

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15 ideas

4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton]
∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [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]
10. Modality / B. Possibility / 7. Chance
Is chance just unknown laws? But the laws operate the same, whatever chance occurs [Peirce]
22. Metaethics / B. Value / 2. Values / e. Death
Is there any such thing as death among the lower organisms? [Peirce]
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
Some kinds are very explanatory, but others less so, and some not at all [Devitt]
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
If the world is just mechanical, its whole specification has no more explanation than mere chance [Peirce]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The more precise the observations, the less reliable appear to be the laws of nature [Peirce]
27. Natural Reality / G. Biology / 5. Species
The higher categories are not natural kinds, so the Linnaean hierarchy should be given up [Devitt]
Species pluralism says there are several good accounts of what a species is [Devitt]