62 ideas
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] |
7334 | Anti-realism needs an intuitionist logic with no law of excluded middle [Dummett, by Miller,A] |
15592 | The usual Tarskian interpretation of variables is to specify their range of values [Fine,K] |
15593 | Variables can be viewed as special terms - functions taking assignments into individuals [Fine,K] |
15590 | It seemed that Frege gave the syntax for variables, and Tarski the semantics, and that was that [Fine,K] |
15591 | In separate expressions variables seem identical in role, but in the same expression they aren't [Fine,K] |
15595 | The 'algebraic' account of variables reduces quantification to the algebra of its component parts [Fine,K] |
15594 | 'Instantial' accounts of variables say we grasp arbitrary instances from their use in quantification [Fine,K] |
10973 | A theory is logically closed, which means infinite premisses [Read] |
15599 | Cicero/Cicero and Cicero/Tully may differ in relationship, despite being semantically the same [Fine,K] |
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] |
10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
10975 | Compactness does not deny that an inference can have infinitely many premisses [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] |
3303 | For anti-realists there are no natural distinctions between objects [Dummett, by Benardete,JA] |
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] |
10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
15603 | I can only represent individuals as the same if I do not already represent them as the same [Fine,K] |
15604 | If Cicero=Tully refers to the man twice, then surely Cicero=Cicero does as well? [Fine,K] |
11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
10989 | The standard view of conditionals is that they are truth-functional [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] |
15602 | Mental files are devices for keeping track of basic coordination of objects [Fine,K] |
15588 | You cannot determine the full content from a thought's intrinsic character, as relations are involved [Fine,K] |
15596 | The standard aim of semantics is to assign a semantic value to each expression [Fine,K] |
15587 | That two utterances say the same thing may not be intrinsic to them, but involve their relationships [Fine,K] |
15589 | The two main theories are Holism (which is inferential), and Representational (which is atomistic) [Fine,K] |
15598 | We should pursue semantic facts as stated by truths in theories (and not put the theories first!) [Fine,K] |
15600 | Referentialist semantics has objects for names, properties for predicates, and propositions for connectives [Fine,K] |
15601 | Fregeans approach the world through sense, Referentialists through reference [Fine,K] |
11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
15605 | I take indexicals such as 'this' and 'that' to be linked to some associated demonstration [Fine,K] |
10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |