27 ideas
5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
5737 | Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia] |
10928 | Maybe we can quantify modally if the objects are intensional, but it seems unlikely [Quine] |
5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
10925 | Failure of substitutivity shows that a personal name is not purely referential [Quine] |
10926 | Quantifying into referentially opaque contexts often produces nonsense [Quine] |
5740 | Second-order logic needs second-order variables and quantification into predicate position [Melia] |
5741 | If every model that makes premises true also makes conclusion true, the argument is valid [Melia] |
5735 | Maybe names and predicates can capture any fact [Melia] |
5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
10930 | Quantification into modal contexts requires objects to have an essence [Quine] |
5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
5738 | We may be sure that P is necessary, but is it necessarily necessary? [Melia] |
5732 | 'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia] |
14645 | To be necessarily greater than 7 is not a trait of 7, but depends on how 7 is referred to [Quine] |
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] |
5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
5734 | Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia] |
5742 | In possible worlds semantics the modal operators are treated as quantifiers [Melia] |
5743 | If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia] |
5749 | Possible worlds could be real as mathematics, propositions, properties, or like books [Melia] |
5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
9203 | We can't quantify in modal contexts, because the modality depends on descriptions, not objects [Quine, by Fine,K] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
10931 | We can't say 'necessarily if x is in water then x dissolves' if we can't quantify modally [Quine] |