Combining Texts

All the ideas for 'Aristotle and Descartes on Matter', 'Logical Consequence' and 'Can there be Vague Objects?'

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15 ideas

5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Validity is explained as truth in all models, because that relies on the logical terms [McGee]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Natural language includes connectives like 'because' which are not truth-functional [McGee]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order variables need to range over more than collections of first-order objects [McGee]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
An ontologically secure semantics for predicate calculus relies on sets [McGee]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logically valid sentences are analytic truths which are just true because of their logical words [McGee]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness theorems are uninformative, because they rely on soundness in their proofs [McGee]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
The culmination of Euclidean geometry was axioms that made all models isomorphic [McGee]
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
Evans argues (falsely!) that a contradiction follows from treating objects as vague [Evans, by Lowe]
Is it coherent that reality is vague, identities can be vague, and objects can have fuzzy boundaries? [Evans]
Evans assumes there can be vague identity statements, and that his proof cannot be right [Evans, by Lewis]
There clearly are vague identity statements, and Evans's argument has a false conclusion [Evans, by Lewis]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
If a=b is indeterminate, then a=/=b, and so there cannot be indeterminate identity [Evans, by Thomasson]
9. Objects / F. Identity among Objects / 6. Identity between Objects
There can't be vague identity; a and b must differ, since a, unlike b, is only vaguely the same as b [Evans, by PG]
19. Language / F. Communication / 2. Assertion
A maxim claims that if we are allowed to assert a sentence, that means it must be true [McGee]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
Prime matter is nothing when it is at rest [Leibniz]