Combining Texts

All the ideas for 'Philosophical Fragments', 'works' and 'First-Order Logic'

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15 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 / A. Nature of Existence / 5. Reason for Existence
I assume existence, rather than reasoning towards it [Kierkegaard]
10. Modality / A. Necessity / 2. Nature of Necessity
Nothing necessary can come into existence, since it already 'is' [Kierkegaard]
15. Nature of Minds / B. Features of Minds / 4. Intentionality / a. Nature of intentionality
How does anything get outside itself? [Fodor, by Martin,CB]
15. Nature of Minds / B. Features of Minds / 4. Intentionality / b. Intentionality theories
Is intentionality outwardly folk psychology, inwardly mentalese? [Lyons on Fodor]
17. Mind and Body / D. Property Dualism / 3. Property Dualism
Are beliefs brains states, but picked out at a "higher level"? [Lyons on Fodor]
18. Thought / B. Mechanics of Thought / 6. Artificial Thought / a. Artificial Intelligence
Is thought a syntactic computation using representations? [Fodor, by Rey]
18. Thought / C. Content / 1. Content
Maybe narrow content is physical, broad content less so [Lyons on Fodor]