Combining Texts

All the ideas for 'The Meditations (To Himself)', 'On Formally Undecidable Propositions' and 'Life of Pythagoras'

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25 ideas

1. Philosophy / A. Wisdom / 2. Wise People
A philosopher should have principles ready for understanding, like a surgeon with instruments [Aurelius]
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 / B. Change in Existence / 1. Nature of Change
Everything is changing, including yourself and the whole universe [Aurelius]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / k. Ethics from nature
Nothing is evil which is according to nature [Aurelius]
22. Metaethics / C. The Good / 3. Pleasure / c. Value of pleasure
Justice has no virtue opposed to it, but pleasure has temperance opposed to it [Aurelius]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / b. Living naturally
The art of life is more like the wrestler's than the dancer's [Aurelius]
24. Political Theory / A. Basis of a State / 1. A People / a. Human distinctiveness
Humans are naturally made for co-operation [Aurelius]
28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question
Pythagoreans believe it is absurd to seek for goodness anywhere except with the gods [Iamblichus]