| 10398 | Natural kinds are not special; they are just well-defined resemblance collections [Abelard, by King,P] |
| 13575 | If there are borderline cases between natural kinds, that makes them superficial [Ellis] |
| 16954 | Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett] |
| 6765 | Nominal essence may well be neither necessary nor sufficient for a natural kind [Kripke, by Bird] |
| 15299 | Species do not have enough constancy to be natural kinds [Harré/Madden] |
| 17375 | Natural kinds are decided entirely by the intentions of our classification [Dupré] |
| 17382 | Cooks, unlike scientists, distinguish garlic from onions [Dupré] |
| 17380 | Wales may count as fish [Dupré] |
| 17379 | Borders between species are much less clear in vegetables than among animals [Dupré] |
| 17384 | Even atoms of an element differ, in the energy levels of their electrons [Dupré] |
| 17387 | Ecologists favour classifying by niche, even though that can clash with genealogy [Dupré] |
| 10351 | Natural kinds are social institutions [Kusch] |