Combining Philosophers

All the ideas for Engelbretsen,G/Sayward,C, Marcus Rossberg and Michael Morris

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25 ideas

1. Philosophy / H. Continental Philosophy / 3. Hermeneutics
Interpreting a text is representing it as making sense [Morris,M]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward]
Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward]
4. Formal Logic / A. Syllogistic Logic / 3. Term Logic
Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward]
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 / D. Assumptions for Logic / 1. Bivalence
Bipolarity adds to Bivalence the capacity for both truth values [Morris,M]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward]
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 / G. Quantification / 1. Quantification
Conjunctive and disjunctive quantifiers are too specific, and are confined to the finite [Morris,M]
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]
Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
To count, we must distinguish things, and have a series with successors in it [Morris,M]
Counting needs to distinguish things, and also needs the concept of a successor in a series [Morris,M]
Discriminating things for counting implies concepts of identity and distinctness [Morris,M]
19. Language / D. Propositions / 1. Propositions
There must exist a general form of propositions, which are predictabe. It is: such and such is the case [Morris,M]