15 ideas
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
8361 | What is true used to be possible, but it may no longer be so [Wright,GHv] |
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] |
1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |