12 ideas
| 13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
| 13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
| 15086 | Absolute necessity might be achievable either logically or metaphysically [Hale] |
| 8261 | Maybe not-p is logically possible, but p is metaphysically necessary, so the latter is not absolute [Hale] |
| 15081 | A strong necessity entails a weaker one, but not conversely; possibilities go the other way [Hale] |
| 15080 | 'Relative' necessity is just a logical consequence of some statements ('strong' if they are all true) [Hale] |
| 15082 | Metaphysical necessity says there is no possibility of falsehood [Hale] |
| 15085 | 'Broadly' logical necessities are derived (in a structure) entirely from the concepts [Hale] |
| 15088 | Logical necessities are true in virtue of the nature of all logical concepts [Hale] |
| 15087 | Conceptual necessities are made true by all concepts [Hale] |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |