60 ideas
4036 | What matters is not how many entities we postulate, but how many kinds of entities [Armstrong, by Mellor/Oliver] |
10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
11011 | Same say there are positive, negative and neuter free logics [Read] |
11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
10986 | Not all validity is captured in first-order logic [Read] |
10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
10973 | A theory is logically closed, which means infinite premisses [Read] |
11007 | Quantifiers are second-order predicates [Read] |
10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
10988 | Any first-order theory of sets is inadequate [Read] |
10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
11016 | Would a language without vagueness be usable at all? [Read] |
11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
15754 | Without properties we would be unable to express the laws of nature [Armstrong] |
4034 | Whether we apply 'cold' or 'hot' to an object is quite separate from its change of temperature [Armstrong] |
8535 | To the claim that every predicate has a property, start by eliminating failure of application of predicate [Armstrong] |
8537 | Tropes fall into classes, because exact similarity is symmetrical and transitive [Armstrong] |
8538 | Trope theory needs extra commitments, to symmetry and non-transitivity, unless resemblance is exact [Armstrong] |
8539 | Universals are required to give a satisfactory account of the laws of nature [Armstrong] |
8529 | Deniers of properties and relations rely on either predicates or on classes [Armstrong] |
8532 | Resemblances must be in certain 'respects', and they seem awfully like properties [Armstrong] |
8530 | Change of temperature in objects is quite independent of the predicates 'hot' and 'cold' [Armstrong] |
8536 | We want to know what constituents of objects are grounds for the application of predicates [Armstrong] |
8531 | In most sets there is no property common to all the members [Armstrong] |
10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
15753 | Essences might support Resemblance Nominalism, but they are too coarse and ill-defined [Armstrong] |
11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
10989 | The standard view of conditionals is that they are truth-functional [Read] |
10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
11017 | Some people even claim that conditionals do not express propositions [Read] |
10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
3102 | Why don't we experience or remember going to sleep at night? [Magee] |
8533 | Predicates need ontological correlates to ensure that they apply [Armstrong] |
4035 | There must be some explanation of why certain predicates are applicable to certain objects [Armstrong] |
11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
8540 | The introduction of sparse properties avoids the regularity theory's problem with 'grue' [Armstrong] |
8541 | Regularities theories are poor on causal connections, counterfactuals and probability [Armstrong] |