16 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] |
15567 | Some events involve no change; they must, because causal histories involve unchanges [Lewis] |
15561 | The events that suit semantics may not be the events that suit causation [Lewis] |
15565 | Events have inbuilt essences, as necessary conditions for their occurrence [Lewis] |
15566 | Events are classes, and so there is a mereology of their parts [Lewis] |
15564 | An event is a property of a unique space-time region [Lewis] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
15563 | Properties are very abundant (unlike universals), and are used for semantics and higher-order variables [Lewis] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
15562 | Causation is a general relation derived from instances of causal dependence [Lewis] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |