67 ideas
7081 | Philosophy is not separate from or above empirical science [Neurath] |
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] |
21752 | Prior to Gödel we thought truth in mathematics consisted in provability [Gödel, by Quine] |
17751 | Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki] |
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] |
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] |
10042 | Reference to a totality need not refer to a conjunction of all its elements [Gödel] |
10620 | Originally truth was viewed with total suspicion, and only demonstrability was accepted [Gödel] |
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] |
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] |
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] |
10271 | Basic mathematics is related to abstract elements of our empirical ideas [Gödel] |
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] |
16661 | There are two sorts of category - referring to things, and to circumstances of things [Boethius] |
15035 | If universals are not separate, we can isolate them by abstraction [Boethius, by Panaccio] |
14665 | We can call the quality of Plato 'Platonity', and say it is a quality which only he possesses [Boethius] |
23308 | Reasoning relates to understanding as time does to eternity [Boethius, by Sorabji] |
10486 | If we are rebuilding our ship at sea, we should jettison some cargo [Boolos on Neurath] |
8485 | We must always rebuild our ship on the open sea; we can't reconstruct it properly in dry-dock [Neurath] |
5771 | Knowledge of present events doesn't make them necessary, so future events are no different [Boethius] |
5767 | Rational natures require free will, in order to have power of judgement [Boethius] |
5769 | Does foreknowledge cause necessity, or necessity cause foreknowledge? [Boethius] |
5768 | God's universal foreknowledge seems opposed to free will [Boethius] |
3192 | Basic logic can be done by syntax, with no semantics [Gödel, by Rey] |
5762 | The wicked want goodness, so they would not be wicked if they obtained it [Boethius] |
5770 | Rewards and punishments are not deserved if they don't arise from free movement of the mind [Boethius] |
5764 | When people fall into wickedness they lose their human nature [Boethius] |
5756 | Happiness is a good which once obtained leaves nothing more to be desired [Boethius] |
5763 | The bad seek the good through desire, but the good through virtue, which is more natural [Boethius] |
5759 | Varied aims cannot be good because they differ, but only become good when they unify [Boethius] |
5754 | You can't control someone's free mind, only their body and possessions [Boethius] |
16692 | Divine eternity is the all-at-once and complete possession of unending life [Boethius] |
5752 | Where does evil come from if there is a god; where does good come from if there isn't? [Boethius] |
5757 | God is the supreme good, so no source of goodness could take precedence over God [Boethius] |
5758 | God is the good [Boethius] |
5760 | The power through which creation remains in existence and motion I call 'God' [Boethius] |
5753 | The regular events of this life could never be due to chance [Boethius] |
5765 | The reward of the good is to become gods [Boethius] |
5761 | God can do anything, but he cannot do evil, so evil must be nothing [Boethius] |
5766 | If you could see the plan of Providence, you would not think there was evil anywhere [Boethius] |