Combining Texts

All the ideas for 'works (all lost)', 'Truthmakers and Converse Barcan Formula' and 'Structures and Structuralism in Phil of Maths'

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30 ideas

3. Truth / B. Truthmakers / 5. What Makes Truths / b. Objects make truths
The truthmaker principle requires some specific named thing to make the difference [Williamson]
3. Truth / B. Truthmakers / 7. Making Modal Truths
Truthmaker is incompatible with modal semantics of varying domains [Williamson]
The converse Barcan formula will not allow contingent truths to have truthmakers [Williamson]
3. Truth / F. Semantic Truth / 2. Semantic Truth
While true-in-a-model seems relative, true-in-all-models seems not to be [Reck/Price]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
If metaphysical possibility is not a contingent matter, then S5 seems to suit it best [Williamson]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
If the domain of propositional quantification is constant, the Barcan formulas hold [Williamson]
Converse Barcan: could something fail to meet a condition, if everything meets that condition? [Williamson]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
ZFC set theory has only 'pure' sets, without 'urelements' [Reck/Price]
5. Theory of Logic / G. Quantification / 1. Quantification
Not all quantification is either objectual or substitutional [Williamson]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
Substitutional quantification is metaphysical neutral, and equivalent to a disjunction of instances [Williamson]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Three types of variable in second-order logic, for objects, functions, and predicates/sets [Reck/Price]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
Not all quantification is objectual or substitutional [Williamson]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
'Analysis' is the theory of the real numbers [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
Mereological arithmetic needs infinite objects, and function definitions [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Peano Arithmetic can have three second-order axioms, plus '1' and 'successor' [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set-theory gives a unified and an explicit basis for mathematics [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Structuralism emerged from abstract algebra, axioms, and set theory and its structures [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / b. Varieties of structuralism
Relativist Structuralism just stipulates one successful model as its arithmetic [Reck/Price]
There are 'particular' structures, and 'universal' structures (what the former have in common) [Reck/Price]
Pattern Structuralism studies what isomorphic arithmetic models have in common [Reck/Price]
There are Formalist, Relativist, Universalist and Pattern structuralism [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
Formalist Structuralism says the ontology is vacuous, or formal, or inference relations [Reck/Price]
Maybe we should talk of an infinity of 'possible' objects, to avoid arithmetic being vacuous [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / d. Platonist structuralism
Universalist Structuralism is based on generalised if-then claims, not one particular model [Reck/Price]
Universalist Structuralism eliminates the base element, as a variable, which is then quantified out [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
The existence of an infinite set is assumed by Relativist Structuralism [Reck/Price]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
If 'fact' is a noun, can we name the fact that dogs bark 'Mary'? [Williamson]
8. Modes of Existence / E. Nominalism / 6. Mereological Nominalism
A nominalist might avoid abstract objects by just appealing to mereological sums [Reck/Price]
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
Our ability to count objects across possibilities favours the Barcan formulas [Williamson]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
A thing can't be the only necessary existent, because its singleton set would be as well [Williamson]