Combining Texts

All the ideas for 'Conceptual truth and metaphysical necessity', 'Possible Worlds' and 'Mathematics is Megethology'

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20 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
Mathematics reduces to set theory, which reduces, with some mereology, to the singleton function [Lewis]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
We can accept the null set, but not a null class, a class lacking members [Lewis]
The null set plays the role of last resort, for class abstracts and for existence [Lewis]
The null set is not a little speck of sheer nothingness, a black hole in Reality [Lewis]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
What on earth is the relationship between a singleton and an element? [Lewis]
Are all singletons exact intrinsic duplicates? [Lewis]
4. Formal Logic / G. Formal Mereology / 1. Mereology
Megethology is the result of adding plural quantification to mereology [Lewis]
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
We can use mereology to simulate quantification over relations [Lewis]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
Mathematics is generalisations about singleton functions [Lewis]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
We don't need 'abstract structures' to have structural truths about successor functions [Lewis]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
I say that absolutely any things can have a mereological fusion [Lewis]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
The necessity of a proposition concerns reality, not our words or concepts [Stalnaker]
Conceptual possibilities are metaphysical possibilities we can conceive of [Stalnaker]
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
Critics say there are just an a priori necessary part, and an a posteriori contingent part [Stalnaker]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A 'centred' world is an ordered triple of world, individual and time [Stalnaker]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
We can take 'ways things might have been' as irreducible elements in our ontology [Stalnaker, by Lycan]
18. Thought / C. Content / 6. Broad Content
Meanings aren't in the head, but that is because they are abstract [Stalnaker]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
One view says the causal story is built into the description that is the name's content [Stalnaker]
19. Language / C. Assigning Meanings / 10. Two-Dimensional Semantics
Two-D says that a posteriori is primary and contingent, and the necessity is the secondary intension [Stalnaker]
In one view, the secondary intension is metasemantic, about how the thinker relates to the content [Stalnaker]