Combining Texts

All the ideas for 'works', 'First-order Logic, 2nd-order, Completeness' and 'Philosophy of Nature (Encylopedia II)'

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13 ideas

1. Philosophy / E. Nature of Metaphysics / 6. Metaphysics as Conceptual
22077 Metaphysics is the lattice which makes incoming material intelligible [Hegel]
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]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
4366 We can't accept Aristotle's naturalism about persons, because it is normative and unscientific [Williams,B, by Hursthouse]
24. Political Theory / C. Ruling a State / 4. Changing the State / c. Revolution
21756 All revolutions result from spirit changing its categories, to achieve a deeper understanding [Hegel]