93 ideas
| 18559 | Philosophy is empty if it does not in some way depend on matters of fact [Machery] |
| 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] |
| 18564 | Do categories store causal knowledge, or typical properties, or knowledge of individuals? [Machery] |
| 18604 | Are quick and slow categorisation the same process, or quite different? [Machery] |
| 18573 | For each category of objects (such as 'dog') an individual seems to have several concepts [Machery] |
| 18602 | A thing is classified if its features are likely to be generated by that category's causal laws [Machery] |
| 18565 | There may be ad hoc categories, such as the things to pack in your suitcase for a trip [Machery] |
| 8704 | Structuralists call a mathematical 'object' simply a 'place in a structure' [Friend] |
| 18570 | There may be several ways to individuate things like concepts [Machery] |
| 12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
| 18616 | If a term doesn't pick out a kind, keeping it may block improvements in classification [Machery] |
| 18614 | Vertical arguments say eliminate a term if it picks out different natural kinds in different theories [Machery] |
| 18615 | Horizontal arguments say eliminate a term if it fails to pick out a natural kind [Machery] |
| 18609 | Psychologists use 'induction' as generalising a property from one category to another [Machery] |
| 18610 | 'Ampliative' induction infers that all members of a category have a feature found in some of them [Machery] |
| 8685 | Studying biology presumes the laws of chemistry, and it could never contradict them [Friend] |
| 18562 | Connectionists cannot distinguish concept-memories from their background, or the processes [Machery] |
| 18561 | We can identify a set of cognitive capacities which are 'higher order' [Machery] |
| 18574 | Concepts for categorisation and for induction may be quite different [Machery] |
| 18588 | Concept theories aim at their knowledge, processes, format, acquisition, and location [Machery] |
| 18611 | We should abandon 'concept', and just use 'prototype', 'exemplar' and 'theory' [Machery] |
| 8688 | Concepts can be presented extensionally (as objects) or intensionally (as a characterization) [Friend] |
| 18567 | In the philosophy of psychology, concepts are usually introduced as constituents of thoughts [Machery] |
| 18569 | In philosophy theories of concepts explain how our propositional attitudes have content [Machery] |
| 18563 | By 'concept' psychologists mean various sorts of representation or structure [Machery] |
| 18558 | Concept theorists examine their knowledge, format, processes, acquisition and location [Machery] |
| 18557 | Psychologists treat concepts as long-term knowledge bodies which lead to judgements [Machery] |
| 18560 | Psychologist treat concepts as categories [Machery] |
| 18592 | The concepts OBJECT or AGENT may be innate [Machery] |
| 18566 | Concepts should contain working memory, not long-term, because they control behaviour [Machery] |
| 18584 | One hybrid theory combines a core definition with a prototype for identification [Machery] |
| 18585 | Heterogeneous concepts might have conflicting judgements, where hybrid theories will not [Machery] |
| 18578 | Concepts as definitions was rejected, and concepts as prototypes, exemplars or theories proposed [Machery] |
| 18575 | The concepts for a class typically include prototypes, and exemplars, and theories [Machery] |
| 18591 | Classical theory can't explain facts like typical examples being categorised quicker [Machery] |
| 18583 | Many categories don't seem to have a definition [Machery] |
| 18590 | Classical theory implies variety in processing times, but this does not generally occur [Machery] |
| 18594 | Knowing typical properties of things is especially useful in induction [Machery] |
| 18593 | The term 'prototype' is used for both typical category members, and the representation [Machery] |
| 18595 | Prototype theories are based on computation of similarities with the prototype [Machery] |
| 18596 | Prototype theorists don't tell us how we select the appropriate prototype [Machery] |
| 18603 | Maybe concepts are not the typical properties, but the ideal properties [Machery] |
| 18605 | It is more efficient to remember the prototype, than repeatedly create it from exemplars [Machery] |
| 18606 | The prototype view predicts that typical members are easier to categorise [Machery] |
| 18597 | Concepts as exemplars are based on the knowledge of properties of each particular [Machery] |
| 18598 | Exemplar theories need to explain how the relevant properties are selected from a multitude of them [Machery] |
| 18599 | In practice, known examples take priority over the rest of the set of exemplars [Machery] |
| 18600 | Theory Theory says category concepts are knowledge stores explaining membership [Machery] |
| 18601 | Theory Theory says concepts are explanatory knowledge, and concepts form domains [Machery] |
| 18607 | Theory theorists rely on best explanation, rather than on similarities [Machery] |
| 18608 | If categorisation is not by similarity, it seems to rely on what properties things might have [Machery] |
| 18587 | The theory account is sometimes labelled as 'knowledge' or 'explanation' in approach [Machery] |
| 18577 | The word 'grandmother' may be two concepts, with a prototype and a definition [Machery] |
| 18589 | For behaviourists concepts are dispositions to link category members to names [Machery] |
| 18612 | Americans are more inclined to refer causally than the Chinese are [Machery] |
| 18613 | Artifacts can be natural kinds, when they are the object of historical enquiry [Machery] |