18 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] |
| 22142 | In future, only logical limits can be placed on divine omnipotence [Anon (Par), by Boulter] |
| 12149 | Indexicals are a problem for beliefs being just subject-proposition relations [Perry] |
| 16716 | It is heresy to require self-evident foundational principles in order to be certain [Anon (Par)] |
| 12151 | If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry] |
| 18412 | Indexicals individuate certain belief states, helping in explanation and prediction [Perry] |
| 12150 | Indexicals reveal big problems with the traditional idea of a proposition [Perry] |
| 1866 | It is heresy to teach that history repeats every 36,000 years [Anon (Par)] |
| 15203 | Tense is essential for thought and action [Perry, by Le Poidevin] |
| 15204 | Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin] |
| 1865 | It is heresy to teach that natural impossibilities cannot even be achieved by God [Anon (Par)] |
| 1864 | It is heresy to teach that we can know God by his essence in this mortal life [Anon (Par)] |