18 ideas
10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
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] |
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] |
8361 | What is true used to be possible, but it may no longer be so [Wright,GHv] |
21788 | The moral will is self-determining, but the ethical will is met in society [Houlgate] |
8363 | p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv] |
8364 | We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv] |
8366 | The very notion of a cause depends on agency and action [Wright,GHv] |
8362 | We give regularities a causal character by subjecting them to experiment [Wright,GHv] |
8360 | We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv] |
8365 | Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv] |