Combining Texts

All the ideas for 'German Philosophy: a very short introduction', 'The Case against Closure (and reply)' and 'First-order Logic, 2nd-order, Completeness'

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


21 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
Second-order logic needs the sets, and its consequence has epistemological problems [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 / 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]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
Transcendental idealism aims to explain objectivity through subjectivity [Bowie]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / d. Absolute idealism
The Idealists saw the same unexplained spontaneity in Kant's judgements and choices [Bowie]
German Idealism tried to stop oppositions of appearances/things and receptivity/spontaneity [Bowie]
Crucial to Idealism is the idea of continuity between receptivity and spontaneous judgement [Bowie]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / c. Knowledge closure
Closure says if you know P, and also know P implies Q, then you must know Q [Dretske]
We needn't regret the implications of our regrets; regretting drinking too much implies the past is real [Dretske]
Knowing by visual perception is not the same as knowing by implication [Dretske]
Reasons for believing P may not transmit to its implication, Q [Dretske]
The only way to preserve our homely truths is to abandon closure [Dretske]
P may imply Q, but evidence for P doesn't imply evidence for Q, so closure fails [Dretske]
We know past events by memory, but we don't know the past is real (an implication) by memory [Dretske]