Combining Texts

All the ideas for 'Croce and Collingwood', 'Semantics for Propositional Attitudes' and 'First-Order Logic'

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14 ideas

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
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 / I. Semantics of Logic / 1. Semantics of Logic
A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
There are three different standard presentations of semantics [Hodges,W]
I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
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 / 6. Mathematics as Set Theory / a. Mathematics is set theory
A 'set' is a mathematically well-behaved class [Hodges,W]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
Our commitments are to an 'ontology', but also to an 'ideology', or conceptual system [Hintikka]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Commitment to possible worlds is part of our ideology, not part of our ontology [Hintikka]
21. Aesthetics / A. Aesthetic Experience / 1. Aesthetics
By 1790 aestheticians were mainly trying to explain individual artistic genius [Kemp]
21. Aesthetics / B. Nature of Art / 4. Art as Expression
Expression can be either necessary for art, or sufficient for art (or even both) [Kemp]
We don't already know what to express, and then seek means of expressing it [Kemp]
The horror expressed in some works of art could equallly be expressed by other means [Kemp]