25 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] |
1630 | We can only see an alien language in terms of our own thought structures (e.g. physical/abstract) [Quine] |
5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
5735 | Maybe names and predicates can capture any fact [Melia] |
5747 | "No entity without identity" - our ontology must contain items with settled identity conditions [Quine, by Melia] |
7925 | There is no proper identity concept for properties, and it is hard to distinguish one from two [Quine] |
13387 | Our conceptual scheme becomes more powerful when we posit abstract objects [Quine] |
8277 | I prefer 'no object without identity' to Quine's 'no entity without identity' [Lowe on 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] |
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] |
17503 | Theories can never represent accurately, because their components are abstract [Cartwright,N, by Portides] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
1631 | You could know the complete behavioural conditions for a foreign language, and still not know their beliefs [Quine] |
1632 | Translation of our remote past or language could be as problematic as alien languages [Quine] |