96 ideas
| 18559 | Philosophy is empty if it does not in some way depend on matters of fact [Machery] |
| 10073 | There cannot be a set theory which is complete [Smith,P] |
| 10616 | Second-order arithmetic can prove new sentences of first-order [Smith,P] |
| 10075 | A 'partial function' maps only some elements to another set [Smith,P] |
| 10074 | A 'total function' maps every element to one element in another set [Smith,P] |
| 10612 | An argument is a 'fixed point' for a function if it is mapped back to itself [Smith,P] |
| 10076 | The 'range' of a function is the set of elements in the output set created by the function [Smith,P] |
| 10605 | Two functions are the same if they have the same extension [Smith,P] |
| 10615 | The Comprehension Schema says there is a property only had by things satisfying a condition [Smith,P] |
| 10595 | A 'theorem' of a theory is a sentence derived from the axioms using the proof system [Smith,P] |
| 10602 | A 'natural deduction system' has no axioms but many rules [Smith,P] |
| 10613 | No nice theory can define truth for its own language [Smith,P] |
| 10078 | An 'injective' ('one-to-one') function creates a distinct output element from each original [Smith,P] |
| 10077 | A 'surjective' ('onto') function creates every element of the output set [Smith,P] |
| 10079 | A 'bijective' function has one-to-one correspondence in both directions [Smith,P] |
| 10070 | If everything that a theory proves is true, then it is 'sound' [Smith,P] |
| 10086 | Soundness is true axioms and a truth-preserving proof system [Smith,P] |
| 10596 | A theory is 'sound' iff every theorem is true (usually from true axioms and truth-preservation) [Smith,P] |
| 10598 | A theory is 'negation complete' if it proves all sentences or their negation [Smith,P] |
| 10597 | 'Complete' applies both to whole logics, and to theories within them [Smith,P] |
| 10069 | A theory is 'negation complete' if one of its sentences or its negation can always be proved [Smith,P] |
| 10609 | Two routes to Incompleteness: semantics of sound/expressible, or syntax of consistency/proof [Smith,P] |
| 10080 | 'Effective' means simple, unintuitive, independent, controlled, dumb, and terminating [Smith,P] |
| 10087 | A theory is 'decidable' if all of its sentences could be mechanically proved [Smith,P] |
| 10088 | Any consistent, axiomatized, negation-complete formal theory is decidable [Smith,P] |
| 10081 | A set is 'enumerable' is all of its elements can result from a natural number function [Smith,P] |
| 10083 | A set is 'effectively enumerable' if a computer could eventually list every member [Smith,P] |
| 10084 | A finite set of finitely specifiable objects is always effectively enumerable (e.g. primes) [Smith,P] |
| 10085 | The set of ordered pairs of natural numbers <i,j> is effectively enumerable [Smith,P] |
| 10601 | The thorems of a nice arithmetic can be enumerated, but not the truths (so they're diffferent) [Smith,P] |
| 10600 | Being 'expressible' depends on language; being 'capture/represented' depends on axioms and proof system [Smith,P] |
| 10599 | For primes we write (x not= 1 ∧ ∀u∀v(u x v = x → (u = 1 ∨ v = 1))) [Smith,P] |
| 10610 | The reals contain the naturals, but the theory of reals doesn't contain the theory of naturals [Smith,P] |
| 10619 | The truths of arithmetic are just true equations and their universally quantified versions [Smith,P] |
| 10618 | All numbers are related to zero by the ancestral of the successor relation [Smith,P] |
| 10608 | The number of Fs is the 'successor' of the Gs if there is a single F that isn't G [Smith,P] |
| 10849 | Baby arithmetic covers addition and multiplication, but no general facts about numbers [Smith,P] |
| 10850 | Baby Arithmetic is complete, but not very expressive [Smith,P] |
| 10852 | Robinson Arithmetic (Q) is not negation complete [Smith,P] |
| 10851 | Robinson Arithmetic 'Q' has basic axioms, quantifiers and first-order logic [Smith,P] |
| 10068 | Natural numbers have zero, unique successors, unending, no circling back, and no strays [Smith,P] |
| 10603 | The logic of arithmetic must quantify over properties of numbers to handle induction [Smith,P] |
| 10848 | Multiplication only generates incompleteness if combined with addition and successor [Smith,P] |
| 10604 | Incompleteness results in arithmetic from combining addition and successor with multiplication [Smith,P] |
| 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] |
| 10617 | The 'ancestral' of a relation is a new relation which creates a long chain of the original relation [Smith,P] |
| 18570 | There may be several ways to individuate things like concepts [Machery] |
| 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] |
| 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] |
| 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] |
| 6649 | Chomsky now says concepts are basically innate, as well as syntax [Chomsky, by Lowe] |
| 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] |