14 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] |
| 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] |
| 10494 | Several words may label a category; one word can name several categories; some categories lack words [Ellen] |
| 16078 | Clay is intrinsically and atomically the same as statue (and that lacks 'modal properties') [Rudder Baker] |
| 16077 | The clay is not a statue - it borrows that property from the statue it constitutes [Rudder Baker] |
| 16080 | Is it possible for two things that are identical to become two separate things? [Rudder Baker] |
| 16076 | Constitution is not identity, as consideration of essential predicates shows [Rudder Baker] |
| 16081 | The constitution view gives a unified account of the relation of persons/bodies, statues/bronze etc [Rudder Baker] |
| 16082 | Statues essentially have relational properties lacked by lumps [Rudder Baker] |