74 ideas
18137 | Impredicative definitions are wrong, because they change the set that is being defined? [Bostock] |
18122 | Classical interdefinitions of logical constants and quantifiers is impossible in intuitionism [Bostock] |
18114 | There is no single agreed structure for set theory [Bostock] |
18107 | A 'proper class' cannot be a member of anything [Bostock] |
18115 | We could add axioms to make sets either as small or as large as possible [Bostock] |
18139 | The Axiom of Choice relies on reference to sets that we are unable to describe [Bostock] |
18105 | Replacement enforces a 'limitation of size' test for the existence of sets [Bostock] |
6548 | Physicalism requires the naturalisation or rejection of set theory [Lycan] |
18108 | First-order logic is not decidable: there is no test of whether any formula is valid [Bostock] |
18109 | The completeness of first-order logic implies its compactness [Bostock] |
18123 | Substitutional quantification is just standard if all objects in the domain have a name [Bostock] |
18120 | The Deduction Theorem is what licenses a system of natural deduction [Bostock] |
18125 | Berry's Paradox considers the meaning of 'The least number not named by this name' [Bostock] |
18101 | Each addition changes the ordinality but not the cardinality, prior to aleph-1 [Bostock] |
18100 | ω + 1 is a new ordinal, but its cardinality is unchanged [Bostock] |
18102 | A cardinal is the earliest ordinal that has that number of predecessors [Bostock] |
18106 | Aleph-1 is the first ordinal that exceeds aleph-0 [Bostock] |
18095 | Instead of by cuts or series convergence, real numbers could be defined by axioms [Bostock] |
18099 | The number of reals is the number of subsets of the natural numbers [Bostock] |
18093 | For Eudoxus cuts in rationals are unique, but not every cut makes a real number [Bostock] |
18110 | Infinitesimals are not actually contradictory, because they can be non-standard real numbers [Bostock] |
18156 | Modern axioms of geometry do not need the real numbers [Bostock] |
18097 | The Peano Axioms describe a unique structure [Bostock] |
18148 | Hume's Principle is a definition with existential claims, and won't explain numbers [Bostock] |
18145 | Many things will satisfy Hume's Principle, so there are many interpretations of it [Bostock] |
18149 | There are many criteria for the identity of numbers [Bostock] |
18143 | Frege makes numbers sets to solve the Caesar problem, but maybe Caesar is a set! [Bostock] |
18116 | Numbers can't be positions, if nothing decides what position a given number has [Bostock] |
18117 | Structuralism falsely assumes relations to other numbers are numbers' only properties [Bostock] |
18141 | Nominalism about mathematics is either reductionist, or fictionalist [Bostock] |
18157 | Nominalism as based on application of numbers is no good, because there are too many applications [Bostock] |
18150 | Actual measurement could never require the precision of the real numbers [Bostock] |
18158 | Ordinals are mainly used adjectively, as in 'the first', 'the second'... [Bostock] |
18127 | Simple type theory has 'levels', but ramified type theory has 'orders' [Bostock] |
18144 | Neo-logicists agree that HP introduces number, but also claim that it suffices for the job [Bostock] |
18147 | Neo-logicists meet the Caesar problem by saying Hume's Principle is unique to number [Bostock] |
18146 | If Hume's Principle is the whole story, that implies structuralism [Bostock] |
18129 | Many crucial logicist definitions are in fact impredicative [Bostock] |
18111 | Treating numbers as objects doesn't seem like logic, since arithmetic fixes their totality [Bostock] |
18159 | Higher cardinalities in sets are just fairy stories [Bostock] |
18155 | A fairy tale may give predictions, but only a true theory can give explanations [Bostock] |
18140 | The best version of conceptualism is predicativism [Bostock] |
18138 | Conceptualism fails to grasp mathematical properties, infinity, and objective truth values [Bostock] |
18131 | If abstracta only exist if they are expressible, there can only be denumerably many of them [Bostock] |
18134 | Predicativism makes theories of huge cardinals impossible [Bostock] |
18135 | If mathematics rests on science, predicativism may be the best approach [Bostock] |
18136 | If we can only think of what we can describe, predicativism may be implied [Bostock] |
18132 | The predicativity restriction makes a difference with the real numbers [Bostock] |
18133 | The usual definitions of identity and of natural numbers are impredicative [Bostock] |
6531 | Institutions are not reducible as types, but they are as tokens [Lycan] |
6532 | Types cannot be reduced, but levels of reduction are varied groupings of the same tokens [Lycan] |
6534 | One location may contain molecules, a metal strip, a key, an opener of doors, and a human tragedy [Lycan] |
6529 | I see the 'role'/'occupant' distinction as fundamental to metaphysics [Lycan] |
6549 | I think greenness is a complex microphysical property of green objects [Lycan] |
6543 | Intentionality comes in degrees [Lycan] |
6537 | Teleological views allow for false intentional content, unlike causal and nomological theories [Lycan] |
6546 | Pain is composed of urges, desires, impulses etc, at different levels of abstraction [Lycan] |
6547 | The right 'level' for qualia is uncertain, though top (behaviourism) and bottom (particles) are false [Lycan] |
6527 | If energy in the brain disappears into thin air, this breaches physical conservation laws [Lycan] |
6528 | In lower animals, psychology is continuous with chemistry, and humans are continuous with animals [Lycan] |
6554 | Two behaviourists meet. The first says,"You're fine; how am I?" [Lycan] |
6545 | If functionalism focuses on folk psychology, it ignores lower levels of function [Lycan] |
6541 | Functionalism must not be too abstract to allow inverted spectrum, or so structural that it becomes chauvinistic [Lycan] |
6539 | The distinction between software and hardware is not clear in computing [Lycan] |
6533 | Mental types are a subclass of teleological types at a high level of functional abstraction [Lycan] |
6535 | Teleological characterisations shade off smoothly into brutely physical ones [Lycan] |
6544 | Identity theory is functionalism, but located at the lowest level of abstraction [Lycan] |
6530 | We reduce the mind through homuncular groups, described abstractly by purpose [Lycan] |
6536 | Teleological functionalism helps us to understand psycho-biological laws [Lycan] |
6542 | A Martian may exhibit human-like behaviour while having very different sensations [Lycan] |
18121 | In logic a proposition means the same when it is and when it is not asserted [Bostock] |
6538 | We need a notion of teleology that comes in degrees [Lycan] |
6551 | 'Physical' means either figuring in physics descriptions, or just located in space-time [Lycan] |
7417 | God can't have silly perfections, but how do we decide which ones are 'silly'? [Joslin] |