Combining Texts

All the ideas for 'Comments on a Certain Broadsheet', 'Frege on Apriority (with ps)' and 'First-order Logic, 2nd-order, Completeness'

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

---

16 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic

10751

Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]

10757

Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]

10759

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

10753

Logical consequence is intuitively semantic, and captured by model theory [Rossberg]

5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-

10752

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

10754

In proof-theory, logical form is shown by the logical constants [Rossberg]

5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models

10756

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

10758

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

10761

Completeness can always be achieved by cunning model-design [Rossberg]

5. Theory of Logic / K. Features of Logics / 5. Incompleteness

10755

A deductive system is only incomplete with respect to a formal semantics [Rossberg]

6. Mathematics / A. Nature of Mathematics / 2. Geometry

16901

The equivalent algebra model of geometry loses some essential spatial meaning [Burge]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic

16902

Peano arithmetic requires grasping 0 as a primitive number [Burge]

12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori

16892

Is apriority predicated mainly of truths and proofs, or of human cognition? [Burge]

12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities

2602	What experience could prove 'If a=c and b=c then a=b'? [Descartes]

18. Thought / D. Concepts / 2. Origin of Concepts / c. Nativist concepts

2600	The mind's innate ideas are part of its capacity for thought [Descartes]

2601	Qualia must be innate, because physical motions do not contain them [Descartes]