64 ideas
21959 | Metaphysics is the most general attempt to make sense of things [Moore,AW] |
9955 | Contextual definitions replace a complete sentence containing the expression [George/Velleman] |
10031 | Impredicative definitions quantify over the thing being defined [George/Velleman] |
10098 | The 'power set' of A is all the subsets of A [George/Velleman] |
10099 | The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman] |
10101 | Cartesian Product A x B: the set of all ordered pairs in which a∈A and b∈B [George/Velleman] |
10103 | Grouping by property is common in mathematics, usually using equivalence [George/Velleman] |
10104 | 'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman] |
10096 | Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman] |
10097 | Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman] |
10100 | Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman] |
17900 | The Axiom of Reducibility made impredicative definitions possible [George/Velleman] |
10109 | ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman] |
10108 | As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman] |
10111 | Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman] |
10129 | A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman] |
10105 | Differences between isomorphic structures seem unimportant [George/Velleman] |
10119 | Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman] |
10126 | A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman] |
10120 | Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman] |
10127 | A 'complete' theory contains either any sentence or its negation [George/Velleman] |
10106 | Rational numbers give answers to division problems with integers [George/Velleman] |
10102 | The integers are answers to subtraction problems involving natural numbers [George/Velleman] |
10107 | Real numbers provide answers to square root problems [George/Velleman] |
9946 | Logicists say mathematics is applicable because it is totally general [George/Velleman] |
10125 | The classical mathematician believes the real numbers form an actual set [George/Velleman] |
17899 | Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman] |
10128 | The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman] |
17902 | A successor is the union of a set with its singleton [George/Velleman] |
10133 | Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman] |
10130 | Set theory can prove the Peano Postulates [George/Velleman] |
10089 | Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman] |
10131 | If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman] |
10092 | In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman] |
10094 | The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman] |
10095 | Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman] |
17901 | Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman] |
10114 | Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman] |
10134 | Much infinite mathematics can still be justified finitely [George/Velleman] |
10123 | The intuitionists are the idealists of mathematics [George/Velleman] |
10124 | Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman] |
4938 | Prior to language, concepts are universals created by self-mapping of brain activity [Edelman/Tononi] |
21958 | Appearances are nothing beyond representations, which is transcendental ideality [Moore,AW] |
4934 | Cultures have a common core of colour naming, based on three axes of colour pairs [Edelman/Tononi] |
4924 | A conscious human being rapidly reunifies its mind after any damage to the brain [Edelman/Tononi] |
4932 | A conscious state endures for about 100 milliseconds, known as the 'specious present' [Edelman/Tononi] |
4931 | Consciousness is a process (of neural interactions), not a location, thing, property, connectivity, or activity [Edelman/Tononi] |
4923 | The three essentials of conscious experience are privateness, unity and informativeness [Edelman/Tononi] |
4941 | Consciousness can create new axioms, but computers can't do that [Edelman/Tononi] |
4930 | Consciousness arises from high speed interactions between clusters of neurons [Edelman/Tononi] |
4929 | Dreams and imagery show the brain can generate awareness and meaning without input [Edelman/Tononi] |
4940 | Physicists see information as a measure of order, but for biologists it is symbolic exchange between animals [Edelman/Tononi] |
4935 | The sensation of red is a point in neural space created by dimensions of neuronal activity [Edelman/Tononi] |
4936 | The self is founded on bodily awareness centred in the brain stem [Edelman/Tononi] |
4939 | A sense of self begins either internally, or externally through language and society [Edelman/Tononi] |
4925 | Brains can initiate free actions before the person is aware of their own decision [Edelman/Tononi] |
4933 | Consciousness is a process, not a thing, as it maintains unity as its composition changes [Edelman/Tononi] |
4928 | Brain complexity balances segregation and integration, like a good team of specialists [Edelman/Tononi] |
4927 | Information-processing views of the brain assume the existence of 'information', and dubious brain codes [Edelman/Tononi] |
4922 | Consciousness involves interaction with persons and the world, as well as brain functions [Edelman/Tononi] |
10110 | Corresponding to every concept there is a class (some of them sets) [George/Velleman] |
5793 | Concepts and generalisations result from brain 'global mapping' by 'reentry' [Edelman/Tononi, by Searle] |
4926 | Concepts arise when the brain maps its own activities [Edelman/Tononi] |
4937 | Systems that generate a sense of value are basic to the primitive brain [Edelman/Tononi] |