22 ideas
19115 | You can 'rebut' an argument's conclusion, or 'undercut' its premises [Antonelli] |
19119 | We infer that other objects are like some exceptional object, if they share some of its properties [Antonelli] |
19111 | Reasoning may be defeated by new premises, or by finding out more about the given ones [Antonelli] |
19113 | Weakest Link Principle: prefer the argument whose weakest link is the stronger [Antonelli] |
19114 | Should we accept Floating Conclusions, derived from two arguments in conflict? [Antonelli] |
19116 | Non-monotonic core: Reflexivity, Cut, Cautious Monotonicity, Left Logical Equivalence, Right Weakening [Antonelli] |
19117 | We can rank a formula by the level of surprise if it were to hold [Antonelli] |
19118 | People don't actually use classical logic, but may actually use non-monotonic logic [Antonelli] |
10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg] |
10759 | There are at least seven possible systems of semantics for second-order logic [Rossberg] |
10751 | Second-order logic needs the sets, and its consequence has epistemological problems [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] |
19110 | In classical logic the relation |= has Monotony built into its definition [Antonelli] |
19112 | Cautious Monotony ignores proved additions; Rational Monotony fails if the addition's negation is proved [Antonelli] |
1757 | The Electra: she knows this man, but not that he is her brother [Eucleides, by Diog. Laertius] |
3028 | The chief good is unity, sometimes seen as prudence, or God, or intellect [Eucleides] |