Combining Philosophers

All the ideas for Critias, Engelbretsen,G/Sayward,C and Charles Parsons

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18 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 / D. Modal Logic ML / 4. Alethic Modal Logic
Modal logic is not an extensional language [Parsons,C]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The old problems with the axiom of choice are probably better ascribed to the law of excluded middle [Parsons,C]
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 / G. Quantification / 4. Substitutional Quantification
Substitutional existential quantifier may explain the existence of linguistic entities [Parsons,C]
On the substitutional interpretation, '(∃x) Fx' is true iff a closed term 't' makes Ft true [Parsons,C]
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]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
Parsons says counting is tagging as first, second, third..., and converting the last to a cardinal [Parsons,C, by Heck]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
General principles can be obvious in mathematics, but bold speculations in empirical science [Parsons,C]
6. Mathematics / C. Sources of Mathematics / 8. Finitism
If functions are transfinite objects, finitists can have no conception of them [Parsons,C]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
If a mathematical structure is rejected from a physical theory, it retains its mathematical status [Parsons,C]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / e. Character
Virtue comes more from habit than character [Critias]
28. God / C. Attitudes to God / 5. Atheism
Fear of the gods was invented to discourage secret sin [Critias]