Combining Texts

All the ideas for 'Philosophical Logic: Intro to Advanced Topics', 'A Specimen of Discoveries' and 'The Concept of Logical Consequence'

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15 ideas

2. Reason / A. Nature of Reason / 4. Aims of Reason
5035 The two basics of reasoning are contradiction and sufficient reason [Leibniz]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
13913 The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward]
13914 Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
13915 Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward]
4. Formal Logic / A. Syllogistic Logic / 3. Term Logic
13916 Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
13850 In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
13849 Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
18812 Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
13344 X follows from sentences K iff every model of K also models X [Tarski]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
13851 Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
13343 A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
13852 Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward]
17. Mind and Body / A. Mind-Body Dualism / 5. Parallelism
5038 Assume that mind and body follow their own laws, but God has harmonised them [Leibniz]
19. Language / E. Analyticity / 1. Analytic Propositions
13345 Sentences are 'analytical' if every sequence of objects models them [Tarski]
29. Religion / D. Religious Issues / 3. Problem of Evil / b. Human Evil
5037 God doesn't decide that Adam will sin, but that sinful Adam's existence is to be preferred [Leibniz]