Combining Texts

All the ideas for 'New Foundations for Mathematical Logic', 'Philosophical Logic: Intro to Advanced Topics' and 'On 'Physics''

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12 ideas

4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward]
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
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
Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
NF has no models, but just blocks the comprehension axiom, to avoid contradictions [Quine, by Dummett]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward]
7. Existence / A. Nature of Existence / 2. Types of Existence
Everything that exists is either a substance or an accident [Albert of Saxony]
9. Objects / E. Objects over Time / 6. Successive Things
God could make a successive thing so that previous parts cease to exist [Albert of Saxony]
Successive entities just need parts to succeed one another, without their existence [Albert of Saxony]