Combining Philosophers

All the ideas for Archimedes, Michael Hallett and Henri Poincar

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11 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
The first-order ZF axiomatisation is highly non-categorical [Hallett,M]
Non-categoricity reveals a sort of incompleteness, with sets existing that the axioms don't reveal [Hallett,M]
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
Zermelo allows ur-elements, to enable the widespread application of set-theory [Hallett,M]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
One geometry cannot be more true than another [Poincaré]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
The General Continuum Hypothesis and its negation are both consistent with ZF [Hallett,M]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Mathematicians do not study objects, but relations between objects [Poincaré]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Convention, yes! Arbitrary, no! [Poincaré, by Putnam]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
Avoid non-predicative classifications and definitions [Poincaré]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The aim of science is just to create a comprehensive, elegant language to describe brute facts [Poincaré, by Harré]