Combining Texts

All the ideas for 'works (all lost)', 'Fourfold Root of Princ of Sufficient Reason' and 'What are Sets and What are they For?'

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26 ideas

2. Reason / B. Laws of Thought / 2. Sufficient Reason
21918 Sufficient Reason can't be proved, because all proof presupposes it [Schopenhauer, by Lewis,PB]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
14239 The empty set is usually derived from Separation, but it also seems to need Infinity [Oliver/Smiley]
14240 The empty set is something, not nothing! [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 / 4. Using Numbers / g. Applying mathematics
14246 If mathematics purely concerned mathematical objects, there would be no applied mathematics [Oliver/Smiley]
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]
7. Existence / D. Theories of Reality / 4. Anti-realism
5953 For the Cyrenaics experience was not enough to give certainty about reality [Aristippus young, by Plutarch]
7. Existence / E. Categories / 1. Categories
21920 No need for a priori categories, since sufficient reason shows the interrelations [Schopenhauer, by Lewis,PB]
10. Modality / A. Necessity / 3. Types of Necessity
21362 Necessity is physical, logical, mathematical or moral [Schopenhauer, by Janaway]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
21361 For Schopenhauer, material things would not exist without the mind [Schopenhauer, by Janaway]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
21919 Object for a subject and representation are the same thing [Schopenhauer]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
21917 The four explanations: objects by causes, concepts by ground, maths by spacetime, ethics by motive [Schopenhauer, by Lewis,PB]
18. Thought / D. Concepts / 2. Origin of Concepts / b. Empirical concepts
21921 Concepts are abstracted from perceptions [Schopenhauer, by Lewis,PB]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
3023 Even the foolish may have some virtues [Aristippus young, by Diog. Laertius]
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
21363 Motivation is causality seen from within [Schopenhauer]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
3026 Actions are influenced by circumstances, so Cyrenaics say felons should be reformed, not hated [Aristippus young, by Diog. Laertius]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
3024 Cyrenaics teach that honour, justice and shame are all based on custom and fashion [Aristippus young, by Diog. Laertius]
23. Ethics / A. Egoism / 1. Ethical Egoism
3025 For a Cyrenaic no one is of equal importance to himself [Aristippus young, by Diog. Laertius]
23. Ethics / A. Egoism / 3. Cyrenaic School
3019 No one pleasure is different from or more pleasant than another [Aristippus young, by Diog. Laertius]
3021 The Cyrenaics asserted that corporeal pleasures were superior to mental ones [Aristippus young, by Diog. Laertius]
23. Ethics / C. Virtue Theory / 4. External Goods / d. Friendship
3027 Cyrenaics say wise men are self-sufficient, needing no friends [Aristippus young, by Diog. Laertius]