12 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] |
| 7810 | The 'Eumenides' of Aeschylus shows blood feuds replaced by law [Aeschylus, by Grayling] |
| 23601 | Leaders can only attack foreigners who have done wrong (as with their own subjects) [Vitoria] |
| 23569 | The only just cause for a war is a wrong received [Vitoria] |
| 23566 | Princes should not justify a war to their subjects, and doing so would undermine the state [Vitoria] |
| 23576 | Sacking a city is lawful if it motivates the attacking troops [Vitoria] |