26 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] |
5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
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] |
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] |
5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
16422 | The necessity of a proposition concerns reality, not our words or concepts [Stalnaker] |
16423 | Conceptual possibilities are metaphysical possibilities we can conceive of [Stalnaker] |
16421 | Critics say there are just an a priori necessary part, and an a posteriori contingent part [Stalnaker] |
16429 | A 'centred' world is an ordered triple of world, individual and time [Stalnaker] |
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] |
12583 | Belief truth-conditions are normal circumstances where the belief is supposed to occur [Papineau] |
16428 | Meanings aren't in the head, but that is because they are abstract [Stalnaker] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
16432 | One view says the causal story is built into the description that is the name's content [Stalnaker] |
16430 | Two-D says that a posteriori is primary and contingent, and the necessity is the secondary intension [Stalnaker] |
16431 | In one view, the secondary intension is metasemantic, about how the thinker relates to the content [Stalnaker] |