17 ideas
| 14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
| 10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
| 10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
| 10429 | It is best to say that a name designates iff there is something for it to designate [Sainsbury] |
| 10425 | Definite descriptions may not be referring expressions, since they can fail to refer [Sainsbury] |
| 10438 | Definite descriptions are usually rigid in subject, but not in predicate, position [Sainsbury] |
| 10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
| 10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
| 13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
| 10833 | Many concepts can only be expressed by second-order logic [Boolos] |
| 15642 | If kinds depend only on what can be observed, many underlying essences might produce the same kind [Eagle] |
| 15645 | Nominal essence are the observable properties of things [Eagle] |
| 15643 | Nominal essence mistakenly gives equal weight to all underlying properties that produce appearances [Eagle] |
| 10432 | A new usage of a name could arise from a mistaken baptism of nothing [Sainsbury] |
| 10434 | Even a quantifier like 'someone' can be used referentially [Sainsbury] |
| 10431 | Things are thought to have a function, even when they can't perform them [Sainsbury] |
| 15641 | Kinds are fixed by the essential properties of things - the properties that make it that kind of thing [Eagle] |