Combining Texts

All the ideas for 'General Draft', 'On Formally Undecidable Propositions' and 'The Unimportance of Identity'

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28 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
22026 Philosophy is homesickness - the urge to be at home everywhere [Novalis]
2. Reason / E. Argument / 7. Thought Experiments
5515 Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
21752 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
17835 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
17886 The limitations of axiomatisation were revealed by the incompleteness theorems [Gödel, by Koellner]
5. Theory of Logic / K. Features of Logics / 2. Consistency
10071 Second Incompleteness: nice theories can't prove their own consistency [Gödel, by Smith,P]
5. Theory of Logic / K. Features of Logics / 3. Soundness
19123 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
10621 Gödel's First Theorem sabotages logicism, and the Second sabotages Hilbert's Programme [Smith,P on Gödel]
17888 The undecidable sentence can be decided at a 'higher' level in the system [Gödel]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
10132 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
3198 Gödel showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey]
10072 First Incompleteness: arithmetic must always be incomplete [Gödel, by Smith,P]
9590 Arithmetical truth cannot be fully and formally derived from axioms and inference rules [Gödel, by Nagel/Newman]
11069 Gödel's Second says that semantic consequence outruns provability [Gödel, by Hanna]
10118 First Incompleteness: a decent consistent system is syntactically incomplete [Gödel, by George/Velleman]
10122 Second Incompleteness: a decent consistent system can't prove its own consistency [Gödel, by George/Velleman]
10611 There is a sentence which a theory can show is true iff it is unprovable [Gödel, by Smith,P]
10867 '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
8747 Realists are happy with impredicative definitions, which describe entities in terms of other existing entities [Gödel, by Shapiro]
7. Existence / C. Structure of Existence / 2. Reduction
5516 Reduction can be by identity, or constitution, or elimination [Parfit, by PG]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
19591 Desire for perfection is an illness, if it turns against what is imperfect [Novalis]
16. Persons / D. Continuity of the Self / 1. Identity and the Self
5514 Psychologists are interested in identity as a type of person, but philosophers study numerical identity [Parfit]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
5521 If my brain-halves are transplanted into two bodies, I have continuity, and don't need identity [Parfit]
5522 Over a period of time what matters is not that 'I' persist, but that I have psychological continuity [Parfit]
16. Persons / D. Continuity of the Self / 4. Split Consciousness
5519 It is fine to save two dying twins by merging parts of their bodies into one, and identity is irrelevant [Parfit]
5520 If two humans are merged surgically, the new identity is a purely verbal problem [Parfit]
16. Persons / E. Rejecting the Self / 4. Denial of the Self
5518 It doesn't matter whether I exist with half my components replaced (any more than an audio system) [Parfit]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
3192 Basic logic can be done by syntax, with no semantics [Gödel, by Rey]