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] |
| 12270 | Being is one [Melissus, by Aristotle] |
| 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] |
| 18969 | How do you distinguish three beliefs from four beliefs or two beliefs? [Quine] |
| 18967 | A 'proposition' is said to be the timeless cognitive part of the meaning of a sentence [Quine] |
| 18968 | The problem with propositions is their individuation. When do two sentences express one proposition? [Quine] |
| 3059 | There is no real motion, only the appearance of it [Melissus, by Diog. Laertius] |
| 5100 | The void is not required for change, because a plenum can alter in quality [Aristotle on Melissus] |
| 18970 | The concept of a 'point' makes no sense without the idea of absolute position [Quine] |
| 456 | Nothing could come out of nothing [Melissus] |