42 ideas
| 19199 | Some say metaphysics is a highly generalised empirical study of objects [Tarski] |
| 19193 | Disputes that fail to use precise scientific terminology are all meaningless [Tarski] |
| 19179 | For a definition we need the words or concepts used, the rules, and the structure of the language [Tarski] |
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| 19178 | Definitions of truth should not introduce a new version of the concept, but capture the old one [Tarski] |
| 19177 | A definition of truth should be materially adequate and formally correct [Tarski] |
| 19186 | A rigorous definition of truth is only possible in an exactly specified language [Tarski] |
| 19194 | We may eventually need to split the word 'true' into several less ambiguous terms [Tarski] |
| 19180 | It is convenient to attach 'true' to sentences, and hence the language must be specified [Tarski] |
| 19181 | In the classical concept of truth, 'snow is white' is true if snow is white [Tarski] |
| 19196 | Scheme (T) is not a definition of truth [Tarski] |
| 19183 | Each interpreted T-sentence is a partial definition of truth; the whole definition is their conjunction [Tarski] |
| 19182 | Use 'true' so that all T-sentences can be asserted, and the definition will then be 'adequate' [Tarski] |
| 19198 | We don't give conditions for asserting 'snow is white'; just that assertion implies 'snow is white' is true [Tarski] |
| 19184 | The best truth definition involves other semantic notions, like satisfaction (relating terms and objects) [Tarski] |
| 19191 | Specify satisfaction for simple sentences, then compounds; true sentences are satisfied by all objects [Tarski] |
| 19188 | We can't use a semantically closed language, or ditch our logic, so a meta-language is needed [Tarski] |
| 19189 | The metalanguage must contain the object language, logic, and defined semantics [Tarski] |
| 10824 | If listing equivalences is a reduction of truth, witchcraft is just a list of witch-victim pairs [Field,H on Tarski] |
| 19190 | We need an undefined term 'true' in the meta-language, specified by axioms [Tarski] |
| 19197 | Truth can't be eliminated from universal claims, or from particular unspecified claims [Tarski] |
| 19185 | Semantics is a very modest discipline which solves no real problems [Tarski] |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| 19195 | Truth tables give prior conditions for logic, but are outside the system, and not definitions [Tarski] |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| 19192 | The truth definition proves semantic contradiction and excluded middle laws (not the logic laws) [Tarski] |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| 19187 | The Liar makes us assert a false sentence, so it must be taken seriously [Tarski] |
| 13804 | A property is essential iff the object would not exist if it lacked that property [Forbes,G] |
| 13805 | Properties are trivially essential if they are not grounded in a thing's specific nature [Forbes,G] |
| 13808 | A relation is essential to two items if it holds in every world where they exist [Forbes,G] |
| 13806 | Trivially essential properties are existence, self-identity, and de dicto necessities [Forbes,G] |
| 13807 | A property is 'extraneously essential' if it is had only because of the properties of other objects [Forbes,G] |
| 13809 | One might be essentialist about the original bronze from which a statue was made [Forbes,G] |
| 13810 | The source of de dicto necessity is not concepts, but the actual properties of the thing [Forbes,G] |