88 ideas
17892 | For clear questions posed by reason, reason can also find clear answers [Gödel] |
10041 | Impredicative Definitions refer to the totality to which the object itself belongs [Gödel] |
9161 | Maybe reasonableness requires circular justifications - that is one coherentist view [Field,H] |
10825 | The notion of truth is to help us make use of the utterances of others [Field,H] |
10820 | In the early 1930s many philosophers thought truth was not scientific [Field,H] |
21752 | Prior to Gödel we thought truth in mathematics consisted in provability [Gödel, by Quine] |
13499 | Tarski reduced truth to reference or denotation [Field,H, by Hart,WD] |
10818 | Tarski really explained truth in terms of denoting, predicating and satisfied functions [Field,H] |
10817 | Tarski just reduced truth to some other undefined semantic notions [Field,H] |
17751 | Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki] |
16186 | The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen] |
16187 | The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen] |
16190 | BF implies that if W possibly had a child, then something is possibly W's child [Simchen] |
8679 | We perceive the objects of set theory, just as we perceive with our senses [Gödel] |
17835 | Gödel show that the incompleteness of set theory was a necessity [Gödel, by Hallett,M] |
9942 | Gödel proved the classical relative consistency of the axiom V = L [Gödel, by Putnam] |
21716 | In simple type theory the axiom of Separation is better than Reducibility [Gödel, by Linsky,B] |
9570 | In Field's Platonist view, set theory is false because it asserts existence for non-existent things [Field,H, by Chihara] |
9188 | Gödel proved that first-order logic is complete, and second-order logic incomplete [Gödel, by Dummett] |
10035 | Mathematical Logic is a non-numerical branch of mathematics, and the supreme science [Gödel] |
10260 | Logical consequence is defined by the impossibility of P and ¬q [Field,H, by Shapiro] |
10042 | Reference to a totality need not refer to a conjunction of all its elements [Gödel] |
10819 | Tarski gives us the account of truth needed to build a group of true sentences in a model [Field,H] |
10620 | Originally truth was viewed with total suspicion, and only demonstrability was accepted [Gödel] |
10827 | Model theory is unusual in restricting the range of the quantifiers [Field,H] |
17886 | The limitations of axiomatisation were revealed by the incompleteness theorems [Gödel, by Koellner] |
10071 | Second Incompleteness: nice theories can't prove their own consistency [Gödel, by Smith,P] |
19123 | If soundness can't be proved internally, 'reflection principles' can be added to assert soundness [Gödel, by Halbach/Leigh] |
17883 | Gödel's Theorems did not refute the claim that all good mathematical questions have answers [Gödel, by Koellner] |
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] |
10038 | A logical system needs a syntactical survey of all possible expressions [Gödel] |
18062 | Set-theory paradoxes are no worse than sense deception in physics [Gödel] |
10132 | There can be no single consistent theory from which all mathematical truths can be derived [Gödel, by George/Velleman] |
9226 | If mathematical theories conflict, it may just be that they have different subject matter [Field,H] |
8958 | In Field's version of science, space-time points replace real numbers [Field,H, by Szabó] |
10046 | The generalized Continuum Hypothesis asserts a discontinuity in cardinal numbers [Gödel] |
10868 | The Continuum Hypothesis is not inconsistent with the axioms of set theory [Gödel, by Clegg] |
13517 | If set theory is consistent, we cannot refute or prove the Continuum Hypothesis [Gödel, by Hart,WD] |
18221 | 'Metric' axioms uses functions, points and numbers; 'synthetic' axioms give facts about space [Field,H] |
17885 | Gödel eventually hoped for a generalised completeness theorem leaving nothing undecidable [Gödel, by Koellner] |
10614 | The real reason for Incompleteness in arithmetic is inability to define truth in a language [Gödel] |
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] |
3198 | Gödel showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey] |
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] |
10039 | Some arithmetical problems require assumptions which transcend arithmetic [Gödel] |
10043 | Mathematical objects are as essential as physical objects are for perception [Gödel] |
8757 | The Indispensability Argument is the only serious ground for the existence of mathematical entities [Field,H] |
18212 | Nominalists try to only refer to physical objects, or language, or mental constructions [Field,H] |
10271 | Basic mathematics is related to abstract elements of our empirical ideas [Gödel] |
10261 | The application of mathematics only needs its possibility, not its truth [Field,H, by Shapiro] |
18218 | Hilbert explains geometry, by non-numerical facts about space [Field,H] |
9623 | Field needs a semantical notion of second-order consequence, and that needs sets [Brown,JR on Field,H] |
18215 | It seems impossible to explain the idea that the conclusion is contained in the premises [Field,H] |
18214 | Mathematics is only empirical as regards which theory is useful [Field,H] |
18216 | Abstractions can form useful counterparts to concrete statements [Field,H] |
8714 | Fictionalists say 2+2=4 is true in the way that 'Oliver Twist lived in London' is true [Field,H] |
18210 | Why regard standard mathematics as truths, rather than as interesting fictions? [Field,H] |
10045 | Impredicative definitions are admitted into ordinary mathematics [Gödel] |
8747 | Realists are happy with impredicative definitions, which describe entities in terms of other existing entities [Gödel, by Shapiro] |
18211 | You can reduce ontological commitment by expanding the logic [Field,H] |
8959 | Field presumes properties can be eliminated from science [Field,H, by Szabó] |
18213 | Abstract objects are only applicable to the world if they are impure, and connect to the physical [Field,H] |
16188 | Serious Actualism says there are no facts at all about something which doesn't exist [Simchen] |
9160 | Lots of propositions are default reasonable, but the a priori ones are empirically indefeasible [Field,H] |
9164 | We treat basic rules as if they were indefeasible and a priori, with no interest in counter-evidence [Field,H] |
9165 | Reliability only makes a rule reasonable if we place a value on the truth produced by reliable processes [Field,H] |
9162 | Believing nothing, or only logical truths, is very reliable, but we want a lot more than that [Field,H] |
9166 | People vary in their epistemological standards, and none of them is 'correct' [Field,H] |
9163 | If we only use induction to assess induction, it is empirically indefeasible, and hence a priori [Field,H] |
18222 | Beneath every extrinsic explanation there is an intrinsic explanation [Field,H] |
3192 | Basic logic can be done by syntax, with no semantics [Gödel, by Rey] |
10826 | 'Valence' and 'gene' had to be reduced to show their compatibility with physicalism [Field,H] |
9917 | 'Abstract' is unclear, but numbers, functions and sets are clearly abstract [Field,H] |
22244 | 'Partial reference' is when the subject thinks two objects are one object [Field,H, by Recanati] |
7615 | Field says reference is a causal physical relation between mental states and objects [Field,H, by Putnam] |
8404 | Explain single events by general rules, or vice versa, or probability explains both, or they are unconnected [Field,H] |
8401 | Physical laws are largely time-symmetric, so they make a poor basis for directional causation [Field,H] |
8400 | Identifying cause and effect is not just conventional; we explain later events by earlier ones [Field,H] |
8402 | The only reason for adding the notion of 'cause' to fundamental physics is directionality [Field,H] |
18223 | In theories of fields, space-time points or regions are causal agents [Field,H] |
18220 | Both philosophy and physics now make substantivalism more attractive [Field,H] |
18219 | Relational space is problematic if you take the idea of a field seriously [Field,H] |