Natural Kinds
Bird (Alexander) & Tobin (Emma)
Source: Stanford Encyclopaedia of Philosophy, 2008-17
Paper - Abstract

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Authors’ Introduction1

  1. Scientific disciplines frequently divide the particulars they study into kinds and theorize about those kinds. To say that a kind is natural is to say that it corresponds to a grouping that reflects the structure of the natural world rather than the interests and actions of human beings. We tend to assume that science is often successful in revealing these kinds; it is a corollary of scientific realism that when all goes well the classifications and taxonomies employed by science correspond to the real kinds in nature. The existence of these real and independent kinds of things is held to justify our scientific inferences and practices.
  2. Putative examples of kinds may be found in all scientific disciplines. Chemistry provides what are taken by many to be the paradigm examples of kinds, the chemical elements, while chemical compounds, such as H2O, are also natural kinds2 of stuff. (Instances of a natural kind3 may be manmade, such as artificially synthesized ascorbic acid (vitamin C); but whether chemical kinds all of whose instances are artificial are natural kinds4 is open to debate. The synthetic transuranium elements, e.g. Rutherfordium, seem good candidates for natural kinds5, whereas artificial molecular kinds such as Buckminsterfullerene, C60, seem less obviously natural kinds6.) The standard model in quantum physics reveals many kinds of fundamental particles (electron, tau neutrino, charm quark), plus broader categories such as kinds of kind (lepton, quark) and higher kinds (fermion, boson). Astronomy classifies the heavenly bodies: galaxies, for example, can be either elliptical, lenticular, or spiral.
  3. Since kinds are revealed by science, a science can revise which kinds it holds exist: phlogisticated air was regarded as a kind until after Lavoisier's chemical revolution. A science can even question a whole category of kinds. Before being superseded in this regard by the chemical elements, biological species were taken to be the best exemplars of kindhood. Yet now it is somewhat controversial to state that species are natural kinds7. As the world changes, its kinds may change too. Rapidly mutating microorganisms demand new classification systems. Kinds in the social sciences, such as economics or sociology, are even more problematic, since the changing norms and practices of individuals and societies may also be held to be constitutive factors in kind membership, and these norms and practices may themselves respond to our classification of people into kinds. These examples are troublesome because there is some tension between the existence of kinds and the mutability of the particulars which are supposed to fall under those kinds. In the case of atoms or galaxies, the particulars under study are typically long-lived and only slowly changing; viruses and economic structures, on the other hand, are more dynamic.
  4. This article divides philosophical discussions of natural kinds8 into three areas: metaphysics, philosophy of science, and philosophy of language.
    1. The metaphysics of natural kinds9 asks whether we should think of our supposed natural kinds10 as genuinely natural. And if they are, what are natural kinds11? And, finally, do natural kinds12 have essences?
    2. Philosophy of science is concerned with natural kinds13 because, as mentioned above, it is the use of natural kinds14 by the individual (‘special’) sciences that generates our interest in them. So we may ask, whether the kinds appearing in our best scientific theories do indeed satisfy the theories of natural kinds15 proposed by the metaphysicians.
    3. Philosophy of language takes an interest in natural kinds16 because basic issues are raised by the semantics17 of natural kind18 terms. For example, if we think of naming an entity and describing it as, semantically speaking, fundamentally different ways of talking about it, should we think of natural kind19 terms as functioning like names or like descriptions?

  1. The Metaphysics of Natural Kinds20
    • 1.1 Natural Classifications
    • 1.2 Natural Kind21 Realism
    • 1.3 Essentialism
  2. Natural Kinds22 in the Special Sciences
  3. The Semantics27 of Natural Kind28 Terms
    • 3.1 Descriptivism and Internalism
    • 3.2 Arguments Against Descriptivism
    • 3.3 Direct Reference and Externalism
    • 3.4 From Reference to Essence?

Detailed Contents & Notes29
  1. The Metaphysics of Natural Kinds30
    • 1.1 Natural Classifications
      • 1.1.1 Naturalism (weak realism)
        1. Members of a natural kind31 should have some (natural) properties in common.
        2. Natural kinds32 should permit inductive inferences
        3. Natural kinds33 should participate in laws of nature
        4. Members of a natural kind34 should form a kind
        5. Natural kinds35 should form a hierarchy
        6. Natural kinds36 should be categorically distinct
      • 1.1.2 Conventionalism (aka constructivism or constructionism)
        1. Weak Conventionalism (epistemological)
        2. Strong Conventionalism (metaphysical)
        3. Mode of dependence on human activity
          1. Material dependence: we make the kinds.
          2. Causal dependence: the relevant facts are caused to be true by the fact that they are believed to be true.
          3. Constitutive dependence: conventions exist in virtue of people holding that they do
      • 1.1.3 Promiscuous Realism:
        1. "Dupre (John) - The Disorder of Things: Metaphysical Foundations of the Disunity of Science".
        2. Not conventionalist, but the structure of the world is vastly complex and can be categorized in many different crosscutting ways, according to the different theoretical interests we happen to be pursuing.
    • 1.2 Natural Kind37 Realism: this is strong realism. It’s not just that there’s a real distinction between kinds of things that is naturally drawn, irrespective of human interests, but that the natural kinds38 themselves really exist. So, not just a collection of gold things, but gold. It’s possible to be a nominalist about natural kinds39 (as abstract entities), while being a realist about the natural classification of individuals into kinds. The analogy is with properties and universals40 (as against classification and natural kinds41).
      • 1.2.1 Quine on Natural Kinds42 and Induction: Kinds are sets. Kind and similarity are essentially one notion. Degrees of similarity. Natural kinds43: Goodman’s grue & Hempel’s raven paradox. Exemplars of natural kinds44 “more similar” than those of gerrymandered kinds. Induction confirmed by natural properties and their instances.
      • 1.2.2 Cluster Kind Realism: a natural kind45 is formed by a cluster of co-occurring properties. Best examples are biological species. Intrinsic and extrinsic homeostatic mechanisms.
      • 1.2.3 Fundamentalism and Reductionism: reductionismnatural kinds46 are species of, or are reducible to, universals47. Natural kind48 fundamentalism denies this. Three views:-
        1. Armstrong: weak realism, but no universals49.
        2. Hawley & Bird: natural kinds50 are complex universals51.
        3. Lowe: natural kinds52 are substantial universals53, an irreducible ontological category. Ellis: also fundamentalist – three hierarchical categories; substantive, dynamic and property kinds.
    • 1.3 Essentialism
  2. Natural Kinds54 in the Special Sciences
  3. The Semantics59 of Natural Kind60 Terms
    • 3.1 Descriptivism and Internalism
    • 3.2 Arguments Against Descriptivism
    • 3.3 Direct Reference and Externalism
    • 3.4 From Reference to Essence?


In-Page Footnotes

Footnote 1: Footnote 29:

Text Colour Conventions (see disclaimer)

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