Combining Texts

All the ideas for 'works', 'Senses of Essence' and 'First-Order Logic'

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16 ideas

2. Reason / D. Definition / 6. Definition by Essence
11178 The essence or definition of an essence involves either a class of properties or a class of propositions [Fine,K]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
10282 Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
11175 Logical concepts rest on certain inferences, not on facts about implications [Fine,K]
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
11176 The property of Property Abstraction says any suitable condition must imply a property [Fine,K]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
10283 A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
10284 There are three different standard presentations of semantics [Hodges,W]
10285 I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
11174 A logical truth is true in virtue of the nature of the logical concepts [Fine,K]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10288 Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
10289 Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
10287 If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
13007 Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
10286 A 'set' is a mathematically well-behaved class [Hodges,W]
9. Objects / D. Essence of Objects / 1. Essences of Objects
11177 Can the essence of an object circularly involve itself, or involve another object? [Fine,K]
9. Objects / D. Essence of Objects / 3. Individual Essences
11173 Being a man is a consequence of his essence, not constitutive of it [Fine,K]
9. Objects / D. Essence of Objects / 4. Essence as Definition
11179 If there are alternative definitions, then we have three possibilities for essence [Fine,K]