12 ideas
| 20947 | Thoughts are learnt through words, so language shows the limits and shape of our knowledge [Herder] |
| 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] |
| 20653 | Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson] |
| 20949 | Study the use of words, not their origins [Herder] |
| 7669 | We cannot attain all the ideals of every culture, so there cannot be a perfect life [Herder, by Berlin] |
| 7668 | Herder invented the idea of being rooted in (or cut off from) a home or a group [Herder, by Berlin] |