Combining Texts

All the ideas for 'Summa totius logicae', 'What are Sets and What are they For?' and 'Forget the 'correspondence theory of truth''

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22 ideas

2. Reason / B. Laws of Thought / 3. Non-Contradiction
9108 From an impossibility anything follows [William of Ockham]
3. Truth / A. Truth Problems / 5. Truth Bearers
10845 To be true a sentence must express a proposition, and not be ambiguous or vague or just expressive [Lewis]
3. Truth / B. Truthmakers / 2. Truthmaker Relation
10847 Truthmakers are about existential grounding, not about truth [Lewis]
3. Truth / B. Truthmakers / 11. Truthmaking and Correspondence
10846 Truthmaker is correspondence, but without the requirement to be one-to-one [Lewis]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
9107 A proposition is true if its subject and predicate stand for the same thing [William of Ockham]
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
16300 Ockham had an early axiomatic account of truth [William of Ockham, by Halbach]
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 / 1. Quantification
9106 The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham]
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]
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
9113 Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham]
7. Existence / A. Nature of Existence / 3. Being / g. Particular being
9110 The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
15388 Universals are single things, and only universal in what they signify [William of Ockham]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
9109 If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham]
19. Language / D. Propositions / 4. Mental Propositions
9105 Some concepts for propositions exist only in the mind, and in no language [William of Ockham]