Combining Texts

All the ideas for 'The Guide of the Perplexed', 'First-Order Logic' and 'A Rsum of Metaphysics'

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13 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]
22. Metaethics / C. The Good / 3. Pleasure / a. Nature of pleasure
Intelligent pleasure is the perception of beauty, order and perfection [Leibniz]
28. God / A. Divine Nature / 2. Divine Nature
We can approach knowledge of God by negative attributes [Maimonides]
28. God / A. Divine Nature / 3. Divine Perfections
Perfection is simply quantity of reality [Leibniz]
28. God / C. Attitudes to God / 4. God Reflects Humanity
Thinking of God as resembling humans results from a bad translation of Genesis 1:26 [Maimonides]
29. Religion / D. Religious Issues / 3. Problem of Evil / b. Human Evil
Evil serves a greater good, and pain is necessary for higher pleasure [Leibniz]