Combining Texts

All the ideas for 'Logical Pluralism', 'Russell's Ontological Development' and 'Identity and Existence in Logic'

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35 ideas

2. Reason / D. Definition / 12. Paraphrase
21699 Russell offered a paraphrase of definite description, to avoid the commitment to objects [Quine]
3. Truth / A. Truth Problems / 1. Truth
13252 Some truths have true negations [Beall/Restall]
3. Truth / B. Truthmakers / 5. What Makes Truths / b. Objects make truths
13247 A truthmaker is an object which entails a sentence [Beall/Restall]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
13249 (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall]
4. Formal Logic / E. Nonclassical Logics / 5. Relevant Logic
13243 Excluded middle must be true for some situation, not for all situations [Beall/Restall]
13245 Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall]
13246 Relevant logic does not abandon classical logic [Beall/Restall]
13254 A doesn't imply A - that would be circular [Beall/Restall]
13255 Relevant logic may reject transitivity [Beall/Restall]
13242 It's 'relevantly' valid if all those situations make it true [Beall/Restall]
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
13250 Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall]
18767 Free logics has terms that do not designate real things, and even empty domains [Anderson,CA]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
13235 Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall]
13238 Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
13234 The view of logic as knowing a body of truths looks out-of-date [Beall/Restall]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
13232 Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall]
5. Theory of Logic / A. Overview of Logic / 8. Logic of Mathematics
13241 The model theory of classical predicate logic is mathematics [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
13253 There are several different consequence relations [Beall/Restall]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
13240 A sentence follows from others if they always model it [Beall/Restall]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
18763 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
18771 Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
13236 Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / d. The Preface paradox
13237 Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall]
7. Existence / A. Nature of Existence / 2. Types of Existence
18769 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
18770 We can distinguish 'ontological' from 'existential' commitment, for different kinds of being [Anderson,CA]
9. Objects / A. Existence of Objects / 4. Impossible objects
18768 We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA]
18766 's is non-existent' cannot be said if 's' does not designate [Anderson,CA]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
18765 Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
18764 The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA]
10. Modality / A. Necessity / 3. Types of Necessity
13244 Relevant necessity is always true for some situation (not all situations) [Beall/Restall]
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
13239 Judgement is always predicating a property of a subject [Beall/Restall]
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
21700 Taking sentences as the unit of meaning makes useful paraphrasing possible [Quine]
21701 Knowing a word is knowing the meanings of sentences which contain it [Quine]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
13248 We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall]
19. Language / D. Propositions / 1. Propositions
13233 Propositions commit to content, and not to any way of spelling it out [Beall/Restall]