66 ideas
11147 | Naturalistic philosophers oppose analysis, preferring explanation to a priori intuition [Margolis/Laurence] |
8721 | An 'impredicative' definition seems circular, because it uses the term being defined [Friend] |
8680 | Classical definitions attempt to refer, but intuitionist/constructivist definitions actually create objects [Friend] |
3678 | Reductio ad absurdum proves an idea by showing that its denial produces contradiction [Friend] |
8705 | Anti-realists see truth as our servant, and epistemically contrained [Friend] |
8713 | In classical/realist logic the connectives are defined by truth-tables [Friend] |
8708 | Double negation elimination is not valid in intuitionist logic [Friend] |
8694 | Free logic was developed for fictional or non-existent objects [Friend] |
8665 | A 'proper subset' of A contains only members of A, but not all of them [Friend] |
8672 | A 'powerset' is all the subsets of a set [Friend] |
8677 | Set theory makes a minimum ontological claim, that the empty set exists [Friend] |
8666 | Infinite sets correspond one-to-one with a subset [Friend] |
8682 | Major set theories differ in their axioms, and also over the additional axioms of choice and infinity [Friend] |
8709 | The law of excluded middle is syntactic; it just says A or not-A, not whether they are true or false [Friend] |
8711 | Intuitionists read the universal quantifier as "we have a procedure for checking every..." [Friend] |
8675 | Paradoxes can be solved by talking more loosely of 'classes' instead of 'sets' [Friend] |
8674 | The Burali-Forti paradox asks whether the set of all ordinals is itself an ordinal [Friend] |
8667 | The 'integers' are the positive and negative natural numbers, plus zero [Friend] |
8668 | The 'rational' numbers are those representable as fractions [Friend] |
8670 | A number is 'irrational' if it cannot be represented as a fraction [Friend] |
8661 | The natural numbers are primitive, and the ordinals are up one level of abstraction [Friend] |
8664 | Cardinal numbers answer 'how many?', with the order being irrelevant [Friend] |
8671 | The 'real' numbers (rationals and irrationals combined) is the Continuum, which has no gaps [Friend] |
8663 | Raising omega to successive powers of omega reveal an infinity of infinities [Friend] |
8662 | The first limit ordinal is omega (greater, but without predecessor), and the second is twice-omega [Friend] |
8669 | Between any two rational numbers there is an infinite number of rational numbers [Friend] |
8676 | Is mathematics based on sets, types, categories, models or topology? [Friend] |
8678 | Most mathematical theories can be translated into the language of set theory [Friend] |
8701 | The number 8 in isolation from the other numbers is of no interest [Friend] |
8702 | In structuralism the number 8 is not quite the same in different structures, only equivalent [Friend] |
8699 | Are structures 'ante rem' (before reality), or are they 'in re' (grounded in physics)? [Friend] |
8696 | Structuralist says maths concerns concepts about base objects, not base objects themselves [Friend] |
8695 | Structuralism focuses on relations, predicates and functions, with objects being inessential [Friend] |
8700 | 'In re' structuralism says that the process of abstraction is pattern-spotting [Friend] |
8681 | The big problem for platonists is epistemic: how do we perceive, intuit, know or detect mathematical facts? [Friend] |
8712 | Mathematics should be treated as true whenever it is indispensable to our best physical theory [Friend] |
8716 | Formalism is unconstrained, so cannot indicate importance, or directions for research [Friend] |
8706 | Constructivism rejects too much mathematics [Friend] |
8707 | Intuitionists typically retain bivalence but reject the law of excluded middle [Friend] |
8704 | Structuralists call a mathematical 'object' simply a 'place in a structure' [Friend] |
11141 | Modern empiricism tends to emphasise psychological connections, not semantic relations [Margolis/Laurence] |
19000 | Read 'all ravens are black' as about ravens, not as about an implication [Belnap] |
17897 | Analytic explanation is wholes in terms of parts; synthetic is parts in terms of wholes or contexts [Belnap] |
11142 | Body-type seems to affect a mind's cognition and conceptual scheme [Margolis/Laurence] |
8685 | Studying biology presumes the laws of chemistry, and it could never contradict them [Friend] |
11121 | Language of thought has subject/predicate form and includes logical devices [Margolis/Laurence] |
8688 | Concepts can be presented extensionally (as objects) or intensionally (as a characterization) [Friend] |
11120 | Concepts are either representations, or abilities, or Fregean senses [Margolis/Laurence] |
11122 | A computer may have propositional attitudes without representations [Margolis/Laurence] |
11124 | Do mental representations just lead to a vicious regress of explanations [Margolis/Laurence] |
11123 | Maybe the concept CAT is just the ability to discriminate and infer about cats [Margolis/Laurence] |
11125 | The abilities view cannot explain the productivity of thought, or mental processes [Margolis/Laurence] |
11140 | Concept-structure explains typicality, categories, development, reference and composition [Margolis/Laurence] |
11128 | Classically, concepts give necessary and sufficient conditions for falling under them [Margolis/Laurence] |
11130 | Typicality challenges the classical view; we see better fruit-prototypes in apples than in plums [Margolis/Laurence] |
11129 | The classical theory explains acquisition, categorization and reference [Margolis/Laurence] |
11131 | It may be that our concepts (such as 'knowledge') have no definitional structure [Margolis/Laurence] |
11132 | The prototype theory is probabilistic, picking something out if it has sufficient of the properties [Margolis/Laurence] |
11133 | Prototype theory categorises by computing the number of shared constituents [Margolis/Laurence] |
11134 | People don't just categorise by apparent similarities [Margolis/Laurence] |
11135 | Complex concepts have emergent properties not in the ingredient prototypes [Margolis/Laurence] |
11136 | Many complex concepts obviously have no prototype [Margolis/Laurence] |
11137 | The theory theory of concepts says they are parts of theories, defined by their roles [Margolis/Laurence] |
11138 | The theory theory is holistic, so how can people have identical concepts? [Margolis/Laurence] |
11139 | Maybe concepts have no structure, and determined by relations to the world, not to other concepts [Margolis/Laurence] |
11146 | People can formulate new concepts which are only named later [Margolis/Laurence] |