Combining Texts

All the ideas for 'Which Logic is the Right Logic?', 'Popular Scientific Lectures' and 'Ontological Dependence'

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29 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / c. Philosophy as generalisation
We understand things through their dependency relations [Fine,K]
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Metaphysics deals with the existence of things and with the nature of things [Fine,K]
1. Philosophy / G. Scientific Philosophy / 2. Positivism
Laws of nature are just records of regularities and correlations, with concepts to make recording them easier [Mach, by Harré]
2. Reason / D. Definition / 4. Real Definition
Maybe two objects might require simultaneous real definitions, as with two simultaneous terms [Fine,K]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
7. Existence / A. Nature of Existence / 3. Being / b. Being and existence
An object's 'being' isn't existence; there's more to an object than existence, and its nature doesn't include existence [Fine,K]
7. Existence / C. Structure of Existence / 4. Ontological Dependence
There is 'weak' dependence in one definition, and 'strong' dependence in all the definitions [Fine,K]
A natural modal account of dependence says x depends on y if y must exist when x does [Fine,K]
An object depends on another if the second cannot be eliminated from the first's definition [Fine,K]
Dependency is the real counterpart of one term defining another [Fine,K]
9. Objects / B. Unity of Objects / 1. Unifying an Object / c. Unity as conceptual
We should understand identity in terms of the propositions it renders true [Fine,K]
9. Objects / D. Essence of Objects / 2. Types of Essence
How do we distinguish basic from derived esssences? [Fine,K]
Maybe some things have essential relationships as well as essential properties [Fine,K]
9. Objects / D. Essence of Objects / 4. Essence as Definition
An object only essentially has a property if that property follows from every definition of the object [Fine,K]