Combining Texts

All the ideas for 'fragments/reports', 'Which Logic is the Right Logic?' and 'Semantic Relationism'

expand these ideas     |    start again     |     specify just one area for these texts


36 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
The usual Tarskian interpretation of variables is to specify their range of values [Fine,K]
Variables can be viewed as special terms - functions taking assignments into individuals [Fine,K]
It seemed that Frege gave the syntax for variables, and Tarski the semantics, and that was that [Fine,K]
In separate expressions variables seem identical in role, but in the same expression they aren't [Fine,K]
The 'algebraic' account of variables reduces quantification to the algebra of its component parts [Fine,K]
'Instantial' accounts of variables say we grasp arbitrary instances from their use in quantification [Fine,K]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
Cicero/Cicero and Cicero/Tully may differ in relationship, despite being semantically the same [Fine,K]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
9. Objects / F. Identity among Objects / 1. Concept of Identity
I can only represent individuals as the same if I do not already represent them as the same [Fine,K]
9. Objects / F. Identity among Objects / 5. Self-Identity
If Cicero=Tully refers to the man twice, then surely Cicero=Cicero does as well? [Fine,K]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Mental files are devices for keeping track of basic coordination of objects [Fine,K]
18. Thought / C. Content / 1. Content
You cannot determine the full content from a thought's intrinsic character, as relations are involved [Fine,K]
19. Language / C. Assigning Meanings / 2. Semantics
The standard aim of semantics is to assign a semantic value to each expression [Fine,K]
That two utterances say the same thing may not be intrinsic to them, but involve their relationships [Fine,K]
The two main theories are Holism (which is inferential), and Representational (which is atomistic) [Fine,K]
We should pursue semantic facts as stated by truths in theories (and not put the theories first!) [Fine,K]
Referentialist semantics has objects for names, properties for predicates, and propositions for connectives [Fine,K]
Fregeans approach the world through sense, Referentialists through reference [Fine,K]
19. Language / C. Assigning Meanings / 9. Indexical Semantics
I take indexicals such as 'this' and 'that' to be linked to some associated demonstration [Fine,K]
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]