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26. Natural Theory / B. Natural Kinds / 7. Critique of Kinds

[objections to dividing nature into 'kinds']

12 ideas
Natural kinds are not special; they are just well-defined resemblance collections [Abelard, by King,P]
     Full Idea: In Abelard's view a natural kind is a well-defined collection of things that have the same features, so that natural kinds have no special status, being no more than discrete integral wholes whose principle of membership is similarity.
     From: report of Peter Abelard (works [1135]) by Peter King - Peter Abelard 2
     A reaction: I take a natural kind to be a completely stable and invariant class of things. Presumably this invariance has an underlying explanation, but Abelard seems to take the Humean line that we cannot penetrate beyond the experienced surface.
If there are borderline cases between natural kinds, that makes them superficial [Ellis]
     Full Idea: There cannot be any borderline cases between the real essences of different natural kinds because, if there were, the distinctions between the kinds would be superficial, like the blue/green distinction.
     From: Brian Ellis (Scientific Essentialism [2001], 1.05)
     A reaction: His particular target here is biological natural kinds, in which he doesn't believe, because they blur across time, in the evolutionary process. Personally I am inclined to relax the notion of a natural kind, otherwise they are too basic to explain.
Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett]
     Full Idea: In my view, Kripke's promotion of 'natural kinds', coverning chemical substances and animal and plant species, is unfortunate, since these are rather different types of things, and words used for them behave differently.
     From: Michael Dummett (Could There Be Unicorns? [1983], 2)
     A reaction: My view is that the only significant difference among natural kinds is their degree of stability in character. Presumably particles, elements and particular molecules are fairly invariant, but living things evolve.
Nominal essence may well be neither necessary nor sufficient for a natural kind [Kripke, by Bird]
     Full Idea: Kripke's tiger example shows that a nominal essence is not necessary for the existence of a natural kind; examples from Putnam show that a nominal essence is not sufficient either.
     From: report of Saul A. Kripke (Naming and Necessity lectures [1970]) by Alexander Bird - Philosophy of Science Ch.3
     A reaction: None of the characteristics of a tiger is essential to it. The appearance of water doesn't fix its reference. The move is towards an external view, that what matters for natural kinds is the real essence, not human conventions about it. I agree.
Species do not have enough constancy to be natural kinds [Harré/Madden]
     Full Idea: We know from biology that naturally occurring species do not exhibit the constancy required by the concept of natural kind.
     From: Harré,R./Madden,E.H. (Causal Powers [1975], 8.IV)
     A reaction: This view has been challenged recently. How much constancy does a natural kind need? Even protons decay eventually, it seems. I think a natural kind just needs a fair degree of stability over a reasonable time-period. Tigers qualify.
Natural kinds are decided entirely by the intentions of our classification [Dupré]
     Full Idea: The question of which natural kind a thing belongs to ....can be answered only in relation to some specification of the goal underlying the intent to classify the object.
     From: John Dupré (The Disorder of Things [1993], Intro)
     A reaction: I don't think I believe this. The situation is complex, and our intents are relevant, but to find an intent which no longer classifies tigers into the same category is wilful silliness.
Cooks, unlike scientists, distinguish garlic from onions [Dupré]
     Full Idea: It would be a severe culinary misfortune if no distinction were drawn between garlic and onions, a distinction that is not reflected in scientific taxonomy.
     From: John Dupré (The Disorder of Things [1993], 1)
     A reaction: Not every persuasive. We distinguish some cows from others because they taste better, but no one thinks that is a serious way in which to classify cows.
Borders between species are much less clear in vegetables than among animals [Dupré]
     Full Idea: The richest source of illustrations is the vegetable kingdom, where specific differences tend to be much less clear than among animals, and considerable developmental plasticity is the rule.
     From: John Dupré (The Disorder of Things [1993], 1)
     A reaction: Nice. Just as the idea that laws of nature are mathematical suits physics, but founders on biology, so natural kinds founder in an area of biology to which we pay less attention. He cites prickly pears and lilies. I'm thinking oranges, satsumas etc.
Wales may count as fish [Dupré]
     Full Idea: The claim that whales are not fish is a debatable one
     From: John Dupré (The Disorder of Things [1993], 1)
     A reaction: A very nice challenge to an almost unquestioned orthodoxy.
Even atoms of an element differ, in the energy levels of their electrons [Dupré]
     Full Idea: Even if we claim that it is really isotopes not atoms that are the natural kinds (thus divorcing chemistry from ordinary language), atoms are said to differ with respect to such features as energy levels of the electrons.
     From: John Dupré (The Disorder of Things [1993], 2)
     A reaction: So we can't just pick out the features of one atom, and say that is the essence. Essence always involves some selection. I say the essence arises from the explanation of the atom's behaviour.
Ecologists favour classifying by niche, even though that can clash with genealogy [Dupré]
     Full Idea: To the extent that the occupants of a particular niche do not coincide with the members of a particular genealogical line, a possibility widely acknowledged to occur, ecologists must favour a method of classification lacking genealogical grounding.
     From: John Dupré (The Disorder of Things [1993], 2)
     A reaction: Zoo keepers probably classify by cages, or which zoo owns what, but that doesn't mean that they reject genealogy. Don't assume ecologists are rejecting any underlying classification that differs from theirs. Compare classification by economists.
Natural kinds are social institutions [Kusch]
     Full Idea: Natural kinds are social institutions.
     From: Martin Kusch (Knowledge by Agreement [2002], Ch.11)
     A reaction: I can see what he means, but I take this to be deeply wrong. A clarification of what exactly is meant by a 'natural kind' is needed before we can make any progress with this one. Is a village a natural kind? Or a poodle? Or a shoal?