Combining Texts

All the ideas for 'fragments/reports', 'Reference and Definite Descriptions' and 'First-order Logic, 2nd-order, Completeness'

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20 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
There are at least seven possible systems of semantics for second-order logic [Rossberg]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In proof-theory, logical form is shown by the logical constants [Rossberg]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / a. Descriptions
Russell only uses descriptions attributively, and Strawson only referentially [Donnellan, by Lycan]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
A definite description can have a non-referential use [Donnellan]
Definite descriptions are 'attributive' if they say something about x, and 'referential' if they pick x out [Donnellan]
'The x is F' only presumes that x exists; it does not actually entail the existence [Donnellan]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
A definite description 'the F' is referential if the speaker could thereby be referring to something not-F [Donnellan, by Sainsbury]
Donnellan is unclear whether the referential-attributive distinction is semantic or pragmatic [Bach on Donnellan]
A description can successfully refer, even if its application to the subject is not believed [Donnellan]
19. Language / B. Reference / 5. Speaker's Reference
Whether a definite description is referential or attributive depends on the speaker's intention [Donnellan]
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]