| 12375 | Whatever holds of a kind intrinsically holds of it necessarily [Aristotle] |
| 5446 | For essentialists two members of a natural kind must be identical [Ellis] |
| 5480 | The whole of our world is a natural kind, so all worlds like it necessarily have the same laws [Ellis] |
| 17053 | Gold's atomic number might not be 79, but if it is, could non-79 stuff be gold? [Kripke] |
| 4964 | 'Cats are animals' has turned out to be a necessary truth [Kripke] |
| 15292 | We can base the idea of a natural kind on the mechanisms that produce natural necessity [Harré/Madden] |
| 11907 | Maybe the identity of kinds is necessary, but instances being of that kind is not [Mackie,P] |