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All the ideas for 'Thinking About Mathematics', 'On Formally Undecidable Propositions' and 'Art'

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51 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 / D. Assumptions for Logic / 2. Excluded Middle
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
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 / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Categories are the best foundation for mathematics [Shapiro]
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 / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
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]
'Impredicative' definitions refer to the thing being described [Shapiro]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
21. Aesthetics / A. Aesthetic Experience / 2. Aesthetic Attitude
Good art produces exaltation and detachment [Bell,C]
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
The word 'beauty' leads to confusion, because it denotes distinct emotions [Bell,C]
21. Aesthetics / A. Aesthetic Experience / 5. Natural Beauty
Our feeling for natural beauty is different from the aesthetic emotion of art [Bell,C]
We only see landscapes as artistic if we ignore their instrumental value [Bell,C]
21. Aesthetics / A. Aesthetic Experience / 6. The Sublime
Visual form can create a sublime mental state [Bell,C]
21. Aesthetics / B. Nature of Art / 1. Defining Art
Art is the expression of an emotion for ultimate reality [Bell,C]
Aestheticism invites artist to create beauty, but with no indication of how to do it [Bell,C]
21. Aesthetics / B. Nature of Art / 2. Art as Form
Only artists can discern significant form; other people must look to art to find it [Bell,C, by Gardner]
Maybe significant form gives us a feeling for ultimate reality [Bell,C]
Significant form is the essence of art, which I believe expresses an emotion about reality [Bell,C]
'Form' is visual relations, and it is 'significant' if it moves us aesthetically; art needs both [Bell,C, by Feagin]
21. Aesthetics / B. Nature of Art / 4. Art as Expression
The only expression art could have is the emotion resulting from pure form [Bell,C]
21. Aesthetics / C. Artistic Issues / 2. Copies of Art
Mere copies of pictures are not significant - unless the copies are very exact [Bell,C]
21. Aesthetics / C. Artistic Issues / 4. Emotion in Art
Art is distinguished by its aesthetic emotion, which produces appropriate form [Bell,C]
21. Aesthetics / C. Artistic Issues / 6. Value of Art
Aesthetic contemplation is the best and most intense mental state [Bell,C]
Aesthetic experience is an exaltation which increases the possibilities of life [Bell,C]
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
Only artistic qualities matter in art, because they also have the highest moral value [Bell,C]
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Religion sees infinite value in some things, and irrelevance in the rest [Bell,C]