30 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] |
17377 | All descriptive language is classificatory [Dupré] |
17376 | We should aim for a classification which tells us as much as possible about the object [Dupré] |
8526 | We might treat both tropes and substances as fundamental, so we can't presume it is just tropes [Daly] |
8527 | More than one trope (even identical ones!) can occupy the same location [Daly] |
8528 | If tropes are linked by the existence of concurrence, a special relation is needed to link them all [Daly] |
17390 | Natural kinds don't need essentialism to be explanatory [Dupré] |
17389 | A species might have its essential genetic mechanism replaced by a new one [Dupré] |
17388 | It seems that species lack essential properties, so they can't be natural kinds [Dupré] |
17374 | The possibility of prediction rests on determinism [Dupré] |
17378 | Presumably molecular structure seems important because we never have the Twin Earth experience [Dupré] |
17381 | Phylogenetics involves history, and cladism rests species on splits in lineage [Dupré] |
17385 | Kinds don't do anything (including evolve) because they are abstract [Dupré] |
17375 | Natural kinds are decided entirely by the intentions of our classification [Dupré] |
17379 | Borders between species are much less clear in vegetables than among animals [Dupré] |
17384 | Even atoms of an element differ, in the energy levels of their electrons [Dupré] |
17387 | Ecologists favour classifying by niche, even though that can clash with genealogy [Dupré] |
17382 | Cooks, unlike scientists, distinguish garlic from onions [Dupré] |
17380 | Wales may count as fish [Dupré] |
17383 | Species are the lowest-level classification in biology [Dupré] |
17386 | The theory of evolution is mainly about species [Dupré] |