Combining Philosophers

All the ideas for Correia,F/Schnieder,B, Hilbert,D/Ackermann,W and Jos L. Zalabardo

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24 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Using modal logic, philosophers tried to handle all metaphysics in modal terms [Correia/Schnieder]
2. Reason / B. Laws of Thought / 2. Sufficient Reason
Why do rationalists accept Sufficient Reason, when it denies the existence of fundamental facts? [Correia/Schnieder]
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo]
A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Determinacy: an object is either in a set, or it isn't [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / l. Axiom of Specification
Specification: Determinate totals of objects always make a set [Zalabardo]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
A first-order 'sentence' is a formula with no free variables [Zalabardo]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo]
Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo]
We can do semantics by looking at given propositions, or by building new ones [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 2. Formal Truth
We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
'Logically true' (|= φ) is true for every truth-assignment [Zalabardo]
Logically true sentences are true in all structures [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo]
A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
If a set is defined by induction, then proof by induction can be applied to it [Zalabardo]
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
Is existential dependence by grounding, or do grounding claims arise from existential dependence? [Correia/Schnieder]
7. Existence / C. Structure of Existence / 1. Grounding / c. Grounding and explanation
Grounding is metaphysical and explanation epistemic, so keep them apart [Correia/Schnieder]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
The identity of two facts may depend on how 'fine-grained' we think facts are [Correia/Schnieder]