Combining Texts

All the ideas for 'The Architecture of Theories', 'Knowledge' and 'First-Order Logic'

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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]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
19724 Belief is knowledge if it is true, certain, and obtained by a reliable process [Ramsey]
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
14802 Physical and psychical laws of mind are either independent, or derived in one or other direction [Peirce]
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
14800 The world is full of variety, but laws seem to produce uniformity [Peirce]
27. Natural Reality / G. Biology / 3. Evolution
14801 Darwinian evolution is chance, with the destruction of bad results [Peirce]