Combining Philosophers

All the ideas for Oliver,A/Smiley,T, George Santayana and Henri Poincar

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19 ideas

1. Philosophy / C. History of Philosophy / 1. History of Philosophy
8000 He who is ignorant of the history of philosophy is doomed to repeat it [Santayana, by MacIntyre]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
14240 The empty set is something, not nothing! [Oliver/Smiley]
14239 The empty set is usually derived from Separation, but it also seems to need Infinity [Oliver/Smiley]
14241 We don't need the empty set to express non-existence, as there are other ways to do that [Oliver/Smiley]
14242 Maybe we can treat the empty set symbol as just meaning an empty term [Oliver/Smiley]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
14243 The unit set may be needed to express intersections that leave a single member [Oliver/Smiley]
5. Theory of Logic / G. Quantification / 6. Plural Quantification
14234 If you only refer to objects one at a time, you need sets in order to refer to a plurality [Oliver/Smiley]
14237 We can use plural language to refer to the set theory domain, to avoid calling it a 'set' [Oliver/Smiley]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
14245 Logical truths are true no matter what exists - but predicate calculus insists that something exists [Oliver/Smiley]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
10245 One geometry cannot be more true than another [Poincaré]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
14246 If mathematics purely concerned mathematical objects, there would be no applied mathematics [Oliver/Smiley]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
15923 Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
14247 Sets might either represent the numbers, or be the numbers, or replace the numbers [Oliver/Smiley]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
10180 Mathematicians do not study objects, but relations between objects [Poincaré]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
9916 Convention, yes! Arbitrary, no! [Poincaré, by Putnam]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
18203 Avoid non-predicative classifications and definitions [Poincaré]
7. Existence / A. Nature of Existence / 6. Criterion for Existence
18521 The criterion of existence is the possibility of action [Santayana]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
23060 The good is not relative, but is rooted in facts about human needs [Santayana]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
15877 The aim of science is just to create a comprehensive, elegant language to describe brute facts [Poincaré, by Harré]