Combining Texts

All the ideas for 'Defending the Axioms', 'Summa Contra Gentiles' and 'Identity and Existence in Logic'

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19 ideas

1. Philosophy / A. Wisdom / 2. Wise People
Wise people should contemplate and discuss the truth, and fight against falsehood [Aquinas]
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Free logics has terms that do not designate real things, and even empty domains [Anderson,CA]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice paradoxically allows decomposing a sphere into two identical spheres [Maddy]
5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism
Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Basic variables in second-order logic are taken to range over subsets of the individuals [Anderson,CA]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Hilbert's geometry and Dedekind's real numbers were role models for axiomatization [Maddy]
If two mathematical themes coincide, that suggest a single deep truth [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
Every infinite set of reals is either countable or of the same size as the full set of reals [Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set-theory tracks the contours of mathematical depth and fruitfulness [Maddy]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
The connection of arithmetic to perception has been idealised away in modern infinitary mathematics [Maddy]
7. Existence / A. Nature of Existence / 2. Types of Existence
Do mathematicians use 'existence' differently when they say some entity exists? [Anderson,CA]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
We can distinguish 'ontological' from 'existential' commitment, for different kinds of being [Anderson,CA]
9. Objects / A. Existence of Objects / 4. Impossible objects
's is non-existent' cannot be said if 's' does not designate [Anderson,CA]
We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA]
17. Mind and Body / A. Mind-Body Dualism / 4. Occasionalism
Without God's influence every operation would stop, so God causes everything [Aquinas]
27. Natural Reality / D. Time / 1. Nature of Time / f. Eternalism
Eternity coexists with passing time, as the centre of a circle coexists with its circumference [Aquinas]