20 ideas
10928 | Maybe we can quantify modally if the objects are intensional, but it seems unlikely [Quine] |
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
10925 | Failure of substitutivity shows that a personal name is not purely referential [Quine] |
10926 | Quantifying into referentially opaque contexts often produces nonsense [Quine] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
10930 | Quantification into modal contexts requires objects to have an essence [Quine] |
14645 | To be necessarily greater than 7 is not a trait of 7, but depends on how 7 is referred to [Quine] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
9201 | Whether 9 is necessarily greater than 7 depends on how '9' is described [Quine, by Fine,K] |
10927 | Necessity only applies to objects if they are distinctively specified [Quine] |
9203 | We can't quantify in modal contexts, because the modality depends on descriptions, not objects [Quine, by Fine,K] |
22480 | Possessing the virtue of justice disposes a person to good practical rationality [Foot] |
22477 | Calling a knife or farmer or speech or root good does not involve attitudes or feelings [Foot] |
22478 | The essential thing is the 'needs' of plants and animals, and their operative parts [Foot] |
22479 | Observing justice is necessary to humans, like hunting to wolves or dancing to bees [Foot] |
10931 | We can't say 'necessarily if x is in water then x dissolves' if we can't quantify modally [Quine] |