Combining Texts

All the ideas for 'Mahaprajnaparamitashastra', 'First-Order Logic' and 'Preface to 'Principles of Philosophy''

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13 ideas

1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
21962 Metaphysics is the roots of the tree of science [Descartes]
2. Reason / F. Fallacies / 4. Circularity
3659 I know the truth that God exists and is the author of truth [Descartes]
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
10288 Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
10289 Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [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 / B. Certain Knowledge / 1. Certainty
3657 Understanding, not the senses, gives certainty [Descartes]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
7903 The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
28. God / C. Attitudes to God / 5. Atheism
3660 Atheism arises from empiricism, because God is intangible [Descartes]