18 ideas
| 10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg] |
| 10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
| 10759 | There are at least seven possible systems of semantics for second-order logic [Rossberg] |
| 10753 | Logical consequence is intuitively semantic, and captured by model theory [Rossberg] |
| 10752 | Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg] |
| 10754 | In proof-theory, logical form is shown by the logical constants [Rossberg] |
| 10756 | A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg] |
| 10758 | If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg] |
| 10761 | Completeness can always be achieved by cunning model-design [Rossberg] |
| 10755 | A deductive system is only incomplete with respect to a formal semantics [Rossberg] |
| 6968 | Some people think there are ethical facts, but of a 'queer' sort [Ayer] |
| 6972 | A right attitude is just an attitude one is prepared to stand by [Ayer] |
| 6973 | Moral theories are all meta-ethical, and are neutral as regards actual conduct [Ayer] |
| 6974 | Moral judgements cannot be the logical consequence of a moral philosophy [Ayer] |
| 6971 | I would describe intuitions of good as feelings of approval [Ayer] |
| 6969 | Approval of historical or fictional murders gives us leave to imitate them [Ayer] |
| 6970 | Moral judgements are not expressions, but are elements in a behaviour pattern [Ayer] |
| 20239 | Unlike us, the early Greeks thought envy was a good thing, and hope a bad thing [Hesiod, by Nietzsche] |