| 15170 | We distinguish species by their nominal essence, not by their real essence [Locke] |
| Full Idea: Our ranking, and distinguishing natural substances into species consists in the nominal essences the mind makes, and not in the real essences to be found in things themselves. | |
| From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 3.06.11) | |
| A reaction: Note that, as far as I can see, Locke never denies the existence of real essences, or even that we might occasionally know them. He is here merely describing, fairly accurately, I think, his empiricist view of how these categories have come about. |
| 16937 | You can't base kinds just on resemblance, because chains of resemblance are a muddle [Quine] |
| Full Idea: If kinds are based on similarity, this has the Imperfect Community problem. Red round, red wooden and round wooden things all resemble one another somehow. There may be nothing outside the set resembling them, so it meets the definition of kind. | |
| From: Willard Quine (Natural Kinds [1969], p.120) | |
| A reaction: [ref. to Goodman 'Structure' 2nd 163- , which attacks Carnap on this] This suggests an invocation of Wittgenstein's family resemblance, which won't be much help for natural kinds. |
| 13583 | There might be uninstantiated natural kinds, such as transuranic elements which have never occurred [Ellis] |
| Full Idea: There are reasons to believe that there are natural kinds that might never be instantiated, such as a transuranic element, capable of existing for some fraction of a second, but which has never actually existed anywhere. | |
| From: Brian Ellis (Scientific Essentialism [2001], 2.05) | |
| A reaction: He cautiously claims that kinds are ontologically prior to their individual members. I would say that there is no natural kind of the type that he describes. He says you have at least some grounds for predicting what kinds are possible. |
| 11860 | Lawlike propensities are enough to individuate natural kinds [Wiggins] |
| Full Idea: For all the purposes of identity and individuation of things that belong to natural kinds..., it is enough to have regard for the lawlike propensities of members of the kind. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.1) | |
| A reaction: This may have got things in reverse, since it is hard to see how you could pick out any laws if you didn't assume the existence of natural kinds which were causing the regularities in the behaviour. |
| 15693 | One sample of gold is enough, but one tree doesn't give the height of trees [Gelman] |
| Full Idea: We can confidently determine the chemical composition of gold from just a single sample, but we cannot determine the height of trees from just a single tree. | |
| From: Susan A. Gelman (The Essential Child [2003], 06 'The role') | |
| A reaction: The tricky word here is 'confidently'. If you meet one Latvian who is nice, do you assume they are all nice? At what point do you decide gold etc. really are natural kinds, where one sample tells all? Evolution of species... |
| 6769 | In the Kripke-Putnam view only nuclear physicists can know natural kinds [Bird] |
| Full Idea: In the Kripke-Putnam view, it is very difficult for anyone except nuclear physicists to pick out natural kinds, since everything else is made out of compounds of different isotopes. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: The concept of a rigid 'natural kind' does not have to be sacred. Tin might be considered a natural kind, despite having 21 isotopes. What matters is protons, not the neutrons. |
| 6774 | Darwinism suggests that we should have a native ability to detect natural kinds [Bird] |
| Full Idea: Creatures that are able to recognise natural kinds and laws have a selective advantage, so Darwinism suggests that we should have some native ability to detect natural kinds. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: This seems right, but it makes 'natural kind' a rather instrumental concept, relative to our interests. True natural kinds cut across our interests, as when we discover by anatomy that whales are not fish, or that rubies and sapphires are both corundum. |
| 14956 | Explanation by kinds and by clusters of properties just express the stability of reality [Ladyman/Ross] |
| Full Idea: Philosophers sometimes invoke natural kinds as if they explain the possibility of explanation. This is characteristically neo-scholastic. That anything can be explained, and that properties cluster together, express one fact: reality is relatively stable. | |
| From: J Ladyman / D Ross (Every Thing Must Go [2007], 5.6) | |
| A reaction: Odd idea. I would have thought that if there are indeed kinds and clusters, this would explain a great deal more than mere stability. Or, more accurately, they would invite a more substantial explanation than mere stability would seem to need. |
| 13285 | Natural kinds support inductive inferences, from previous samples to the next one [Koslicki] |
| Full Idea: Natural kinds are said to stand out from other classifications because they support legitimate inductive inferences ...as when we observe that past samples of copper conduct electricity and infer that the next sample will too. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.3.1) | |
| A reaction: A slightly more precise version of the Upanishad definition of natural kinds which I favour (Idea 8153). If you can't predict the next one from the previous one, it isn't a natural kind. You can't quite predict the next tiger from the previous one. |