Combining Texts

All the ideas for 'Thinking About Mathematics', 'On Formally Undecidable Propositions' and 'Contemporary Political Philosophy (1st edn)'

expand these ideas     |    start again     |     specify just one area for these texts


62 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]
16. Persons / E. Rejecting the Self / 2. Self as Social Construct
The 'Kantian' self steps back from commitment to its social situation [Kymlicka]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
Basic logic can be done by syntax, with no semantics [Gödel, by Rey]
22. Metaethics / C. The Good / 1. Goodness / c. Right and good
Teleological theories give the good priority over concern for people [Kymlicka]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / c. Particularism
Maybe the particularist moral thought of women is better than the impartial public thinking of men [Kymlicka]
23. Ethics / E. Utilitarianism / 1. Utilitarianism
Utilitarianism is not a decision-procedure; choice of the best procedure is an open question [Kymlicka]
One view says start with equality, and infer equal weight to interests, and hence maximum utility [Kymlicka]
A second view says start with maximising the good, implying aggregation, and hence equality [Kymlicka]
24. Political Theory / A. Basis of a State / 2. Population / a. Human population
To maximise utility should we double the population, even if life somewhat deteriorates? [Kymlicka]
24. Political Theory / A. Basis of a State / 4. Original Position / c. Difference principle
The difference principles says we must subsidise the costs of other people's choices [Kymlicka]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / c. Social contract
Social contract theories are usually rejected because there never was such a contract [Kymlicka]
24. Political Theory / D. Ideologies / 4. Social Utilitarianism
Utilitarianism is no longer a distinctive political position [Kymlicka]
The quest of the general good is partly undermined by people's past entitlements [Kymlicka]
We shouldn't endorse preferences which reject equality, and show prejudice and selfishness [Kymlicka]
Using utilitarian principles to make decisions encourages cold detachment from people [Kymlicka]
Utilitarianism is irrational if it tells you to trade in your rights and resources just for benefits [Kymlicka]
24. Political Theory / D. Ideologies / 6. Liberalism / b. Liberal individualism
Modern liberalism has added personal privacy to our personal social lives [Kymlicka]
24. Political Theory / D. Ideologies / 6. Liberalism / d. Liberal freedom
Liberalism tends to give priority to basic liberties [Kymlicka]
24. Political Theory / D. Ideologies / 6. Liberalism / g. Liberalism critique
Marxists say liberalism is unjust, because it allows exploitation in the sale of labour [Kymlicka]
24. Political Theory / D. Ideologies / 7. Communitarianism / a. Communitarianism
The 'Kantian' view of the self misses the way it is embedded or situated in society [Kymlicka]
Communitarians say we should pay more attention to our history [Kymlicka]
24. Political Theory / D. Ideologies / 7. Communitarianism / b. Against communitarianism
Communitarian states only encourage fairly orthodox ideas of the good life [Kymlicka]
25. Social Practice / A. Freedoms / 1. Slavery
If everyone owned himself, that would prevent slavery [Kymlicka]
25. Social Practice / A. Freedoms / 4. Free market
Libertarians like the free market, but they also think that the free market is just [Kymlicka]
25. Social Practice / A. Freedoms / 5. Freedom of lifestyle
The most valuable liberties to us need not be the ones with the most freedom [Kymlicka]
25. Social Practice / A. Freedoms / 6. Political freedom
Ancient freedom was free participation in politics, not private independence of life [Kymlicka]
25. Social Practice / B. Equalities / 2. Political equality
Equal opportunities seems fair, because your fate is from your choices, not your circumstances [Kymlicka]
Equal opportunity arbitrarily worries about social circumstances, but ignores talents [Kymlicka]
25. Social Practice / B. Equalities / 3. Legal equality
Marxists say justice is unneeded in the truly good community [Kymlicka]
25. Social Practice / C. Rights / 1. Basis of Rights
The Lockean view of freedom depends on whether you had a right to what is restricted [Kymlicka]
25. Social Practice / D. Justice / 1. Basis of justice
Justice corrects social faults, but also expresses respect to individuals as ends [Kymlicka]