Combining Texts

All the ideas for 'Ways of Worldmaking', '26: Oracles in Decline' and 'On Formally Undecidable Propositions'

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32 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Without words or other symbols, we have no world [Goodman]
3. Truth / A. Truth Problems / 5. Truth Bearers
Truth is irrelevant if no statements are involved [Goodman]
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]
7. Existence / C. Structure of Existence / 4. Ontological Dependence
Being primitive or prior always depends on a constructional system [Goodman]
7. Existence / C. Structure of Existence / 5. Supervenience / d. Humean supervenience
We don't recognise patterns - we invent them [Goodman]
7. Existence / D. Theories of Reality / 3. Reality
Reality is largely a matter of habit [Goodman]
7. Existence / D. Theories of Reality / 4. Anti-realism
We build our world, and ignore anything that won't fit [Goodman]
7. Existence / E. Categories / 5. Category Anti-Realism
A world can be full of variety or not, depending on how we sort it [Goodman]
9. Objects / F. Identity among Objects / 3. Relative Identity
Things can only be judged the 'same' by citing some respect of sameness [Goodman]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
The sun is always bright; it doesn't become bright when it emerges [Plutarch]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
Discovery is often just finding a fit, like a jigsaw puzzle [Goodman]
14. Science / B. Scientific Theories / 3. Instrumentalism
Users of digital thermometers recognise no temperatures in the gaps [Goodman]
14. Science / B. Scientific Theories / 5. Commensurability
We lack frames of reference to transform physics, biology and psychology into one another [Goodman]
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
Grue and green won't be in the same world, as that would block induction entirely [Goodman]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
26. Natural Theory / A. Speculations on Nature / 1. Nature
If the world is one it has many aspects, and if there are many worlds they will collect into one [Goodman]