96 ideas
| 7001 | If you begin philosophy with language, you find yourself trapped in it [Heil] |
| 7037 | Parsimony does not imply the world is simple, but that our theories should try to be [Heil] |
| 7038 | A theory with few fundamental principles might still posit a lot of entities [Heil] |
| 9955 | Contextual definitions replace a complete sentence containing the expression [George/Velleman] |
| 10031 | Impredicative definitions quantify over the thing being defined [George/Velleman] |
| 7004 | The view that truth making is entailment is misguided and misleading [Heil] |
| 10098 | The 'power set' of A is all the subsets of A [George/Velleman] |
| 10101 |
Cartesian Product A x B: the set of all ordered pairs |
| 10099 | The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman] |
| 10103 | Grouping by property is common in mathematics, usually using equivalence [George/Velleman] |
| 10104 | 'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman] |
| 10096 | Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman] |
| 10097 | Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman] |
| 10100 | Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman] |
| 17900 | The Axiom of Reducibility made impredicative definitions possible [George/Velleman] |
| 10109 | ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman] |
| 7035 | God does not create the world, and then add the classes [Heil] |
| 10108 | As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman] |
| 10111 | Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman] |
| 10129 | A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman] |
| 10105 | Differences between isomorphic structures seem unimportant [George/Velleman] |
| 10119 | Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman] |
| 10126 | A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman] |
| 10120 | Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman] |
| 10127 | A 'complete' theory contains either any sentence or its negation [George/Velleman] |
| 10106 | Rational numbers give answers to division problems with integers [George/Velleman] |
| 10102 | The integers are answers to subtraction problems involving natural numbers [George/Velleman] |
| 10107 | Real numbers provide answers to square root problems [George/Velleman] |
| 9946 | Logicists say mathematics is applicable because it is totally general [George/Velleman] |
| 10125 | The classical mathematician believes the real numbers form an actual set [George/Velleman] |
| 17899 | Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman] |
| 10128 | The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman] |
| 17902 | A successor is the union of a set with its singleton [George/Velleman] |
| 10133 | Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman] |
| 10130 | Set theory can prove the Peano Postulates [George/Velleman] |
| 10089 | Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman] |
| 10131 | If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman] |
| 10092 | In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman] |
| 10094 | The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman] |
| 10095 | Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman] |
| 17901 | Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman] |
| 10114 | Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman] |
| 10134 | Much infinite mathematics can still be justified finitely [George/Velleman] |
| 10123 | The intuitionists are the idealists of mathematics [George/Velleman] |
| 10124 | Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman] |
| 7017 | The reductionist programme dispenses with levels of reality [Heil] |
| 7003 | There are levels of organisation, complexity, description and explanation, but not of reality [Heil] |
| 7045 | Realism says some of our concepts 'cut nature at the joints' [Heil] |
| 7065 | Anti-realists who reduce reality to language must explain the existence of language [Heil] |
| 7020 | Concepts don't carve up the world, which has endless overlooked or ignored divisions [Heil] |
| 7007 | I think of properties as simultaneously dispositional and qualitative [Heil] |
| 7015 | A predicate applies truly if it picks out a real property of objects [Heil] |
| 7042 | A theory of universals says similarity is identity of parts; for modes, similarity is primitive [Heil] |
| 7023 | Powers or dispositions are usually seen as caused by lower-level qualities [Heil] |
| 7025 | Are a property's dispositions built in, or contingently added? [Heil] |
| 7034 | Universals explain one-over-many relations, and similar qualities, and similar behaviour [Heil] |
| 7039 | How could you tell if the universals were missing from a world of instances? [Heil] |
| 7009 | Similarity among modes will explain everthing universals were for [Heil] |
| 7041 | Similar objects have similar properties; properties are directly similar [Heil] |
| 7032 | Objects join sets because of properties; the property is not bestowed by set membership [Heil] |
| 7008 | Trope theorists usually see objects as 'bundles' of tropes [Heil] |
| 7018 | Objects are substances, which are objects considered as the bearer of properties [Heil] |
| 7019 | Maybe there is only one substance, space-time or a quantum field [Heil] |
| 7046 | Rather than 'substance' I use 'objects', which have properties [Heil] |
| 7047 | Statues and bronze lumps have discernible differences, so can't be identical [Heil] |
| 7048 | Do we reduce statues to bronze, or eliminate statues, or allow statues and bronze? [Heil] |
| 7028 | If properties were qualities without dispositions, they would be undetectable [Heil] |
| 7029 | Can we distinguish the way a property is from the property? [Heil] |
| 7030 | Properties don't possess ways they are, because that just is the property [Heil] |
| 7051 | Objects only have secondary qualities because they have primary qualities [Heil] |
| 7044 | Secondary qualities are just primary qualities considered in the light of their effect on us [Heil] |
| 7052 | Colours aren't surface properties, because of radiant sources and the colour of the sky [Heil] |
| 7053 | Treating colour as light radiation has the implausible result that tomatoes are not red [Heil] |
| 8800 | If you would deny a truth if you know the full evidence, then knowledge has social aspects [Harman, by Sosa] |
| 7066 | If the world is just texts or social constructs, what are texts and social constructs? [Heil] |
| 7021 | If the world is theory-dependent, the theories themselves can't be theory-dependent [Heil] |
| 7026 | Science is sometimes said to classify powers, neglecting qualities [Heil] |
| 7060 | One form of explanation is by decomposition [Heil] |
| 7010 | Dispositionality provides the grounding for intentionality [Heil] |
| 7054 | Intentionality now has internalist (intrinsic to thinkers) and externalist (environment or community) views [Heil] |
| 7011 | Qualia are not extra appendages, but intrinsic ingredients of material states and processes [Heil] |
| 7061 | Philosophers' zombies aim to show consciousness is over and above the physical world [Heil] |
| 7063 | Zombies are based on the idea that consciousness relates contingently to the physical [Heil] |
| 7064 | Functionalists deny zombies, since identity of functional state means identity of mental state [Heil] |
| 7027 | Functionalists say objects can be the same in disposition but differ in quality [Heil] |
| 7062 | Functionalism cannot explain consciousness just by functional organisation [Heil] |
| 7059 | The 'explanatory gap' is used to say consciousness is inexplicable, at least with current concepts [Heil] |
| 7012 | If a car is a higher-level entity, distinct from its parts, how could it ever do anything? [Heil] |
| 7043 | Multiple realisability is actually one predicate applying to a diverse range of properties [Heil] |
| 7058 | Externalism is causal-historical, or social, or biological [Heil] |
| 7057 | Intentionality is based in dispositions, which are intrinsic to agents, suggesting internalism [Heil] |
| 10110 | Corresponding to every concept there is a class (some of them sets) [George/Velleman] |
| 7013 | The Picture Theory claims we can read reality from our ways of speaking about it [Heil] |
| 7002 | If propositions are states of affairs or sets of possible worlds, these lack truth values [Heil] |
| 7016 | The standard view is that causal sequences are backed by laws, and between particular events [Heil] |
| 7036 | The real natural properties are sparse, but there are many complex properties [Heil] |