Combining Texts

All the ideas for 'fragments/reports', 'A Slim Book about Narrow Content' and 'On Formally Undecidable Propositions'

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38 ideas

1. Philosophy / G. Scientific Philosophy / 1. Aims of Science
Science is in the business of carving nature at the joints [Segal]
2. Reason / A. Nature of Reason / 8. Naturalising Reason
Psychology studies the way rationality links desires and beliefs to causality [Segal]
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]
10. Modality / A. Necessity / 5. Metaphysical Necessity
Is 'Hesperus = Phosphorus' metaphysically necessary, but not logically or epistemologically necessary? [Segal]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
If claims of metaphysical necessity are based on conceivability, we should be cautious [Segal]
14. Science / D. Explanation / 3. Best Explanation / c. Against best explanation
The success and virtue of an explanation do not guarantee its truth [Segal]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
18. Thought / A. Modes of Thought / 4. Folk Psychology
Folk psychology is ridiculously dualist in its assumptions [Segal]
18. Thought / C. Content / 5. Twin Earth
If 'water' has narrow content, it refers to both H2O and XYZ [Segal]
Humans are made of H2O, so 'twins' aren't actually feasible [Segal]
Externalists can't assume old words refer to modern natural kinds [Segal]
18. Thought / C. Content / 6. Broad Content
Concepts can survive a big change in extension [Segal]
Must we relate to some diamonds to understand them? [Segal]
Maybe content involves relations to a language community [Segal]
Externalism can't explain concepts that have no reference [Segal]
If content is external, so are beliefs and desires [Segal]
Maybe experts fix content, not ordinary users [Segal]
18. Thought / C. Content / 7. Narrow Content
If content is narrow, my perfect twin shares my concepts [Segal]
18. Thought / C. Content / 10. Causal Semantics
If thoughts ARE causal, we can't explain how they cause things [Segal]
Even 'mass' cannot be defined in causal terms [Segal]
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]