Combining Texts

All the ideas for '27: Book of Daniel', 'First-Order Logic' and 'Summula philosophiae naturalis'

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12 ideas

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 / 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 / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10289 Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
10288 Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [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 / 6. Mathematics as Set Theory / a. Mathematics is set theory
10286 A 'set' is a mathematically well-behaved class [Hodges,W]
7. Existence / E. Categories / 5. Category Anti-Realism
16608 Ockham was an anti-realist about the categories [William of Ockham, by Pasnau]
9. Objects / C. Structure of Objects / 4. Quantity of an Object
16599 Ockham says matter must be extended, so we don't need Quantity [William of Ockham, by Pasnau]
16681 Matter gets its quantity from condensation and rarefaction, which is just local motion [William of Ockham]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
7482 Resurrection developed in Judaism as a response to martyrdoms, in about 160 BCE [Anon (Dan), by Watson]