Combining Texts

All the ideas for 'Two Problems of Epistemology', 'On Formally Undecidable Propositions' and 'Properties'

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36 ideas

2. Reason / B. Laws of Thought / 6. Ockham's Razor
What matters is not how many entities we postulate, but how many kinds of entities [Armstrong, by Mellor/Oliver]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Prior to Gödel we thought truth in mathematics consisted in provability [Gödel, by Quine]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Gödel show that the incompleteness of set theory was a necessity [Gödel, by Hallett,M]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
The limitations of axiomatisation were revealed by the incompleteness theorems [Gödel, by Koellner]
5. Theory of Logic / K. Features of Logics / 2. Consistency
Second Incompleteness: nice theories can't prove their own consistency [Gödel, by Smith,P]
5. Theory of Logic / K. Features of Logics / 3. Soundness
If soundness can't be proved internally, 'reflection principles' can be added to assert soundness [Gödel, by Halbach/Leigh]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
Gödel's First Theorem sabotages logicism, and the Second sabotages Hilbert's Programme [Smith,P on Gödel]
The undecidable sentence can be decided at a 'higher' level in the system [Gödel]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
There can be no single consistent theory from which all mathematical truths can be derived [Gödel, by George/Velleman]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Gödel showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey]
First Incompleteness: arithmetic must always be incomplete [Gödel, by Smith,P]
Arithmetical truth cannot be fully and formally derived from axioms and inference rules [Gödel, by Nagel/Newman]
Gödel's Second says that semantic consequence outruns provability [Gödel, by Hanna]
First Incompleteness: a decent consistent system is syntactically incomplete [Gödel, by George/Velleman]
Second Incompleteness: a decent consistent system can't prove its own consistency [Gödel, by George/Velleman]
There is a sentence which a theory can show is true iff it is unprovable [Gödel, by Smith,P]
'This system can't prove this statement' makes it unprovable either way [Gödel, by Clegg]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
Realists are happy with impredicative definitions, which describe entities in terms of other existing entities [Gödel, by Shapiro]
8. Modes of Existence / B. Properties / 2. Need for Properties
Without properties we would be unable to express the laws of nature [Armstrong]
8. Modes of Existence / B. Properties / 10. Properties as Predicates
Whether we apply 'cold' or 'hot' to an object is quite separate from its change of temperature [Armstrong]
To the claim that every predicate has a property, start by eliminating failure of application of predicate [Armstrong]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes fall into classes, because exact similarity is symmetrical and transitive [Armstrong]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
Trope theory needs extra commitments, to symmetry and non-transitivity, unless resemblance is exact [Armstrong]
8. Modes of Existence / D. Universals / 2. Need for Universals
Universals are required to give a satisfactory account of the laws of nature [Armstrong]
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Deniers of properties and relations rely on either predicates or on classes [Armstrong]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblances must be in certain 'respects', and they seem awfully like properties [Armstrong]
8. Modes of Existence / E. Nominalism / 3. Predicate Nominalism
Change of temperature in objects is quite independent of the predicates 'hot' and 'cold' [Armstrong]
We want to know what constituents of objects are grounds for the application of predicates [Armstrong]
8. Modes of Existence / E. Nominalism / 5. Class Nominalism
In most sets there is no property common to all the members [Armstrong]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essences might support Resemblance Nominalism, but they are too coarse and ill-defined [Armstrong]
14. Science / A. Basis of Science / 6. Falsification
Particulars can be verified or falsified, but general statements can only be falsified (conclusively) [Popper]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
19. Language / C. Assigning Meanings / 3. Predicates
Predicates need ontological correlates to ensure that they apply [Armstrong]
There must be some explanation of why certain predicates are applicable to certain objects [Armstrong]
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Regularities theories are poor on causal connections, counterfactuals and probability [Armstrong]
The introduction of sparse properties avoids the regularity theory's problem with 'grue' [Armstrong]