Combining Texts

All the ideas for 'German Philosophy: a very short introduction', 'Boole calculus and the Concept script' and 'First-Order Logic'

expand these ideas     |    start again     |     specify just one area for these texts

13 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]
10285 I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
10284 There are three different standard presentations of semantics [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]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
22049 Transcendental idealism aims to explain objectivity through subjectivity [Bowie]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / d. Absolute idealism
22055 The Idealists saw the same unexplained spontaneity in Kant's judgements and choices [Bowie]
22054 German Idealism tried to stop oppositions of appearances/things and receptivity/spontaneity [Bowie]
22056 Crucial to Idealism is the idea of continuity between receptivity and spontaneous judgement [Bowie]
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
18265 We don't judge by combining subject and concept; we get a concept by splitting up a judgement [Frege]