Combining Texts

All the ideas for 'Chomsky on himself', 'On Formally Undecidable Propositions' and 'A Powers Theory of Modality'

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32 ideas

3. Truth / B. Truthmakers / 11. Truthmaking and Correspondence
Unlike correspondence, truthmaking can be one truth to many truthmakers, or vice versa [Jacobs]
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 / A. Relations / 3. Structural Relations
If structures result from intrinsic natures of properties, the 'relations' between them can drop out [Jacobs]
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
Science aims at identifying the structure and nature of the powers that exist [Jacobs]
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
Powers come from concrete particulars, not from the laws of nature [Jacobs]
10. Modality / A. Necessity / 10. Impossibility
Possibilities are manifestations of some power, and impossibilies rest on no powers [Jacobs]
10. Modality / B. Possibility / 1. Possibility
States of affairs are only possible if some substance could initiate a causal chain to get there [Jacobs]
10. Modality / B. Possibility / 9. Counterfactuals
Counterfactuals invite us to consider the powers picked out by the antecedent [Jacobs]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Possible worlds are just not suitable truthmakers for modality [Jacobs]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
All modality is in the properties and relations of the actual world [Jacobs]
10. Modality / C. Sources of Modality / 6. Necessity from Essence
We can base counterfactuals on powers, not possible worlds, and hence define necessity [Jacobs]
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
Concrete worlds, unlike fictions, at least offer evidence of how the actual world could be [Jacobs]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
If some book described a possibe life for you, that isn't what makes such a life possible [Jacobs]
Possible worlds semantics gives little insight into modality [Jacobs]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
18. Thought / D. Concepts / 2. Origin of Concepts / c. Nativist concepts
Chomsky now says concepts are basically innate, as well as syntax [Chomsky, by Lowe]