Combining Texts

All the ideas for 'Conspectus libelli (book outline)', 'Foundations of Geometry' and 'First-order Logic, 2nd-order, Completeness'

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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 / C. Ontology of Logic / 3. If-Thenism
10053 Geometrical axioms imply the propositions, but the former may not be true [Russell]
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 / B. Foundations for Mathematics / 3. Axioms for Geometry
10052 Geometry is united by the intuitive axioms of projective geometry [Russell, by Musgrave]
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
12699 A body would be endless disunited parts, if it did not have a unifying form or soul [Leibniz]
9. Objects / C. Structure of Objects / 2. Hylomorphism / d. Form as unifier
12700 Form or soul gives unity and duration; matter gives multiplicity and change [Leibniz]
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
12736 If we understand God and his choices, we have a priori knowledge of contingent truths [Leibniz, by Garber]
17. Mind and Body / A. Mind-Body Dualism / 3. Panpsychism
12698 Every body contains a kind of sense and appetite, or a soul [Leibniz]