Combining Texts

All the ideas for 'fragments/reports', 'First-order Logic, 2nd-order, Completeness' and 'Philosophy of Science'

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


20 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]
14. Science / A. Basis of Science / 6. Falsification
Why abandon a theory if you don't have a better one? [Gorham]
If a theory is more informative it is less probable [Gorham]
14. Science / B. Scientific Theories / 1. Scientific Theory
Is Newton simpler with universal simultaneity, or Einstein simpler without absolute time? [Gorham]
Structural Realism says mathematical structures persist after theory rejection [Gorham]
Structural Realists must show the mathematics is both crucial and separate [Gorham]
14. Science / B. Scientific Theories / 3. Instrumentalism
For most scientists their concepts are not just useful, but are meant to be true and accurate [Gorham]
Theories aren't just for organising present experience if they concern the past or future [Gorham]
14. Science / D. Explanation / 2. Types of Explanation / d. Consilience
Consilience makes the component sciences more likely [Gorham]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
A virtue is a combination of intelligence, strength and luck [Ion]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Aristotelian physics has circular celestial motion and linear earthly motion [Gorham]