Combining Texts

All the ideas for 'The Value of Science', 'Inessential Aristotle: Powers without Essences' and 'First-Order Logic'

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15 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]
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
15148 Powers give explanations, without being necessary for some class membership [Chakravartty]
9. Objects / D. Essence of Objects / 5. Essence as Kind
15145 A kind essence is the necessary and sufficient properties for membership of a class [Chakravartty]
9. Objects / D. Essence of Objects / 15. Against Essentialism
15147 Cluster kinds are explained simply by sharing some properties, not by an 'essence' [Chakravartty]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
15144 Explanation of causal phenomena concerns essential kinds - but also lack of them [Chakravartty]
26. Natural Theory / B. Natural Kinds / 4. Source of Kinds
15146 Some kinds, such as electrons, have essences, but 'cluster kinds' do not [Chakravartty]
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
15151 Many causal laws do not refer to kinds, but only to properties [Chakravartty]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
15877 The aim of science is just to create a comprehensive, elegant language to describe brute facts [Poincaré, by Harré]