87 ideas
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] |
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] |
10605 | Two functions are the same if they have the same extension [Smith,P] |
10075 | A 'partial function' maps only some elements to another set [Smith,P] |
10076 | The 'range' of a function is the set of elements in the output set created by the function [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] |
10079 | A 'bijective' function has one-to-one correspondence in both directions [Smith,P] |
10077 | A 'surjective' ('onto') function creates every element of the output set [Smith,P] |
10078 | An 'injective' ('one-to-one') function creates a distinct output element from each original [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] |
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] |
10080 | 'Effective' means simple, unintuitive, independent, controlled, dumb, and terminating [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] |
10851 | Robinson Arithmetic 'Q' has basic axioms, quantifiers and first-order logic [Smith,P] |
10852 | Robinson Arithmetic (Q) is not negation complete [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] |
10604 | Incompleteness results in arithmetic from combining addition and successor with multiplication [Smith,P] |
10848 | Multiplication only generates incompleteness if combined with addition and successor [Smith,P] |
16062 | A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow] |
16061 | If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow] |
16060 | Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow] |
16064 | The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow] |
10617 | The 'ancestral' of a relation is a new relation which creates a long chain of the original relation [Smith,P] |
7871 | Perceptual concepts can't just refer to what causes classification [Papineau] |
7852 | The only serious mind-brain theories now are identity, token identity, realization and supervenience [Papineau] |
7864 | Maybe mind and body do overdetermine acts, but are linked (for some reason) [Papineau] |
7873 | Young children can see that other individuals sometimes have false beliefs [Papineau] |
7874 | Do we understand other minds by simulation-theory, or by theory-theory? [Papineau] |
7882 | Researching phenomenal consciousness is peculiar, because the concepts involved are peculiar [Papineau] |
7854 | Whether octopuses feel pain is unclear, because our phenomenal concepts are too vague [Papineau] |
7889 | Our concept of consciousness is crude, and lacks theoretical articulation [Papineau] |
7891 | We can’t decide what 'conscious' means, so it is undecidable whether cats are conscious [Papineau] |
7890 | Maybe a creature is conscious if its mental states represent things in a distinct way [Papineau] |
7885 | The 'actualist' HOT theory says consciousness comes from actual higher judgements of mental states [Papineau] |
7886 | Actualist HOT theories imply that a non-conscious mental event could become conscious when remembered [Papineau] |
7887 | States are conscious if they could be the subject of higher-order mental judgements [Papineau] |
7888 | Higher-order judgements may be possible where the subject denies having been conscious [Papineau] |
7860 | The epiphenomenal relation of mind and brain is a 'causal dangler', unlike anything else [Papineau] |
7862 | Maybe minds do not cause actions, but do cause us to report our decisions [Papineau] |
7870 | Role concepts either name the realising property, or the higher property constituting the role [Papineau] |
7858 | If causes are basic particulars, this doesn't make conscious and physical properties identical [Papineau] |
7865 | Supervenience can be replaced by identifying mind with higher-order or disjunctional properties [Papineau] |
7892 | The completeness of physics is needed for mind-brain identity [Papineau] |
7879 | Mind-brain reduction is less explanatory, because phenomenal concepts lack causal roles [Papineau] |
20971 | Weak reduction of mind is to physical causes; strong reduction is also to physical laws [Papineau] |
7856 | It is absurd to think that physical effects are caused twice, so conscious causes must be physical [Papineau] |
7881 | Accept ontological monism, but conceptual dualism; we think in a different way about phenomenal thought [Papineau] |
7866 | Mary acquires new concepts; she previously thought about the same property using material concepts [Papineau] |
7850 | Thinking about a thing doesn't require activating it [Papineau] |
7851 | Consciousness affects bodily movement, so thoughts must be material states [Papineau] |
7884 | Most reductive accounts of representation imply broad content [Papineau] |
7863 | If content hinges on matters outside of you, how can it causally influence your actions? [Papineau] |
7883 | Verificationists tend to infer indefinite answers from undecidable questions [Papineau] |
7872 | Teleosemantics equates meaning with the item the concept is intended to track [Papineau] |
7869 | Truth conditions in possible worlds can't handle statements about impossibilities [Papineau] |
7868 | Thought content is possible worlds that make the thought true; if that includes the actual world, it's true [Papineau] |
7853 | Causation is based on either events, or facts, or states of affairs [Papineau] |
7857 | Causes are instantiations of properties by particulars, or they are themselves basic particulars [Papineau] |
20976 | The completeness of physics cannot be proved [Papineau] |
20974 | Modern biological research, especially into the cell, has revealed no special new natural forces [Papineau] |
20970 | Determinism is possible without a complete physics, if mental forces play a role [Papineau] |
20975 | Quantum 'wave collapses' seem to violate conservation of energy [Papineau] |