41 ideas
| 5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
| 15647 | Truth definitions don't produce a good theory, because they go beyond your current language [Halbach] |
| 15649 | In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach] |
| 15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach] |
| 15654 | If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach] |
| 15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach] |
| 15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
| 15656 | Deflationists say truth merely serves to express infinite conjunctions [Halbach] |
| 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] |
| 15657 | To prove the consistency of set theory, we must go beyond set theory [Halbach] |
| 15652 | We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach] |
| 15651 | Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach] |
| 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] |
| 12056 | An ancestral relation is either direct or transitively indirect [Wiggins] |
| 12050 | Substances contain a source of change or principle of activity [Wiggins] |
| 12052 | We never single out just 'this', but always 'this something-or-other' [Wiggins] |
| 12055 | Sortal predications are answers to the question 'what is x?' [Wiggins] |
| 12059 | A river may change constantly, but not in respect of being a river [Wiggins] |
| 12063 | Sortal classification becomes science, with cross reference clarifying individuals [Wiggins] |
| 12051 | If the kinds are divided realistically, they fall into substances [Wiggins] |
| 12053 | 'Human being' is a better answer to 'what is it?' than 'poet', as the latter comes in degrees [Wiggins] |
| 12054 | Secondary substances correctly divide primary substances by activity-principles and relations [Wiggins] |
| 12047 | We refer to persisting substances, in perception and in thought, and they aid understanding [Wiggins] |
| 12057 | Matter underlies things, composes things, and brings them to be [Wiggins] |
| 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] |
| 12064 | The category of substance is more important for epistemology than for ontology [Wiggins] |
| 12049 | Naming the secondary substance provides a mass of general information [Wiggins] |
| 12065 | Seeing a group of soldiers as an army is irresistible, in ontology and explanation [Wiggins] |
| 5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |