32 ideas
| 5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
| 19504 | My modus ponens might be your modus tollens [Pritchard,D] |
| 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] |
| 19503 | An improbable lottery win can occur in a nearby possible world [Pritchard,D] |
| 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] |
| 19505 | Moore begs the question, or just offers another view, or uses 'know' wrongly [Pritchard,D, by PG] |
| 19499 | We can have evidence for seeing a zebra, but no evidence for what is entailed by that [Pritchard,D] |
| 19500 | Favouring: an entailment will give better support for the first belief than reason to deny the second [Pritchard,D] |
| 19502 | Maybe knowledge just needs relevant discriminations among contrasting cases [Pritchard,D] |
| 19498 | Epistemic internalism usually says justification must be accessible by reflection [Pritchard,D] |
| 19506 | Externalism is better than internalism in dealing with radical scepticism [Pritchard,D] |
| 19496 | Disjunctivism says perceptual justification must be both factual and known by the agent [Pritchard,D] |
| 19497 | Metaphysical disjunctivism says normal perceptions and hallucinations are different experiences [Pritchard,D] |
| 19495 | Epistemic externalism struggles to capture the idea of epistemic responsibility [Pritchard,D] |
| 19501 | We assess error against background knowledge, but that is just what radical scepticism challenges [Pritchard,D] |
| 19507 | Radical scepticism is merely raised, and is not a response to worrying evidence [Pritchard,D] |
| 20921 | How can we state relativism of sweet and sour, if they have no determinate nature? [Theophrastus] |
| 5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
| 5990 | Theophrastus doubted whether nature could be explained teleologically [Theophrastus, by Gottschalk] |