Combining Texts

All the ideas for 'fragments/reports', 'On Formally Undecidable Propositions' and 'Nature Without Essence'

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33 ideas

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]
5. Theory of Logic / K. Features of Logics / 6. Compactness
If a concept is not compact, it will not be presentable to finite minds [Almog]
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 / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
The number series is primitive, not the result of some set theoretic axioms [Almog]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
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 showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey]
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 / A. Nature of Existence / 3. Being / d. Non-being
Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]
9. Objects / D. Essence of Objects / 4. Essence as Definition
Fregean meanings are analogous to conceptual essence, defining a kind [Almog]
Essential definition aims at existence conditions and structural truths [Almog]
Surface accounts aren't exhaustive as they always allow unintended twin cases [Almog]
Definitionalists rely on snapshot-concepts, instead of on the real processes [Almog]
9. Objects / D. Essence of Objects / 10. Essence as Species
Alien 'tigers' can't be tigers if they are not related to our tigers [Almog]
9. Objects / D. Essence of Objects / 13. Nominal Essence
Kripke and Putnam offer an intermediary between real and nominal essences [Almog]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Individual essences are just cobbled together classificatory predicates [Almog]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
18. Thought / C. Content / 5. Twin Earth
Water must be related to water, just as tigers must be related to tigers [Almog]
19. Language / F. Communication / 1. Rhetoric
Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]
Destroy seriousness with laughter, and laughter with seriousness [Gorgias]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
Defining an essence comes no where near giving a thing's nature [Almog]
Essences promise to reveal reality, but actually drive us away from it [Almog]