{"agent_id":"kripke","agent_name":"Saul Kripke","slug":"natural-kind-terms","label":"Natural kind terms: are they rigid designators in the same sense as proper names, and do theoretical identifications come out necessary?","topic":"Natural kind terms","question":"Are they rigid designators in the same sense as proper names, and do theoretical identifications come out necessary?","position":"Natural kind terms — \"water,\" \"gold,\" \"tiger,\" \"heat\" — are *rigid designators* of the kinds they refer to, much as proper names are rigid designators of individuals. The reference is fixed at the actual world by samples (this stuff is water; that stuff is gold) plus the implicit methodological commitment that what matters for being of the kind is its underlying nature, discoverable empirically. Theoretical identifications between rigidly designating natural-kind terms are thus *necessary if true*, though typically discovered a posteriori: \"water is H2O,\" \"gold is the element with atomic number 79,\" \"heat is molecular motion.\" A possible world in which something looks like water, behaves like water, and yet is not H2O is a world in which something *resembles* water but is not water; the same kind is wherever H2O is, regardless of superficial properties.","paragraphs":[[{"t":"Natural kind terms — \"water,\" \"gold,\" \"tiger,\" \"heat\" — are *rigid designators* of the kinds they refer to, much as proper names are rigid designators of individuals.","n":[1,2]},{"t":"The reference is fixed at the actual world by samples (this stuff is water; that stuff is gold) plus the implicit methodological commitment that what matters for being of the kind is its underlying nature, discoverable empirically.","n":[]}],[{"t":"Theoretical identifications between rigidly designating natural-kind terms are thus *necessary if true*, though typically discovered a posteriori: \"water is H2O,\" \"gold is the element with atomic number 79,\" \"heat is molecular motion.\" A possible world in which something looks like water, behaves like water, and yet is not H2O is a world in which something *resembles* water but is not water; the same kind is wherever H2O is, regardless of superficial properties.","n":[3,4]}]],"texts":"*Naming and Necessity* (1980), Lecture III; \"Identity and Necessity\" (1971, *Philosophical Troubles* Ch 1). Reception: Hilary Putnam's \"The Meaning of 'Meaning'\" (1975) as an independent parallel development of natural-kind externalism; Scott Soames's *Beyond Rigidity* Ch 9-11, arguing that there is no natural way to extend the singular-term concept of rigidity to predicates that vindicates the central N&N doctrines; Joseph LaPorte's *Natural Kinds and Conceptual Change* (2004); Michael Devitt and Kim Sterelny on natural kinds; the broader scientific-realism literature on essentialism about chemical and biological kinds.","works":["*Naming and Necessity* (1980), Lecture III","\"Identity and Necessity\" (1971, *Philosophical Troubles* Ch 1)"],"reception":"Hilary Putnam's \"The Meaning of 'Meaning'\" (1975) as an independent parallel development of natural-kind externalism; Scott Soames's *Beyond Rigidity* Ch 9-11, arguing that there is no natural way to extend the singular-term concept of rigidity to predicates that vindicates the central N&N doctrines; Joseph LaPorte's *Natural Kinds and Conceptual Change* (2004); Michael Devitt and Kim Sterelny on natural kinds; the broader scientific-realism literature on essentialism about chemical and biological kinds.","status":"The central insight — that theoretical identifications between natural-kind terms are necessary a posteriori, and that the natural sciences uncover necessary truths about the world — survives in the post-Kripke and post-Putnam literature as a near-consensus. The technical claim that natural-kind terms are rigid in the same sense as singular terms is more contested. Soames argues at length in *Beyond Rigidity* Ch 9 that there is no natural concept of rigidity for predicates that does the work N&N attributes to it — that all natural-kind predicates come out rigid, while familiar descriptive predicates like *is a bachelor* do not, and that theoretical identifications involving rigid predicates must be necessary. Soames offers a more limited vindication; I find the critique persuasive on the formulation while continuing to hold the underlying necessary-a-posteriori claim.","era":"1940-2022","discipline":"Philosophy","refs":[{"n":1,"work":"Naming and Necessity","page":"pp. 147–148","canonical":"","quote":"Only such anti-scientific fundamentalists as Bryan cast aspersions on the effort.) More important, the species-name may be passed from link to link, exactly as in the case of proper names, so that many who have seen little or no gold can still use the term. Their reference is determined by a causal (historical) chain, not by use of any items.","label":"Naming and Necessity, pp. 147–148"},{"n":2,"work":"Naming and Necessity","page":"pp. 136–137","canonical":"","quote":"More recent philosophy has followed suit, except that, in the case of both proper names and natural kind terms, it often replaces the notion of defining properties by that of a cluster of properties, only some of which need to be satisfied in each particular case. My own view, on the other hand, regards Mill as more-or-less right about 'singular' names, but wrong about 'general' names.","label":"Naming and Necessity, pp. 136–137"},{"n":3,"work":"Reference and Existence","page":"p. 45","canonical":"","quote":"Tigers are a natural kind, and to be a tiger one must be of that natural kind. So it is not the case that any animal looking like this need be a tiger by defi nition. Of course, we may hope or believe that no such perfect ringers exist. Th e less they do, the easier it is to identify species by their appearances.","label":"Reference and Existence, p. 45"},{"n":4,"work":"Reference and Existence","page":"p. 46","canonical":"","quote":"I recall reading a couple of references that att ribute to Putnam the idea that only impurities in the gold around us produce the apparent yellow color, and that chemically pure gold would not be yellow. Epistemically, this is certainly a possibility, and an elegant way of bringing out the point that 'gold is yellow' is not *a priori* certain.","label":"Reference and Existence, p. 46"}],"answer":null,"siblings":[{"slug":"rigid-designation","label":"Rigid designation: are proper names synonymous with descriptions, or do they designate the same individual across all possible worlds?"},{"slug":"necessity-vs-apriority","label":"Necessity vs apriority: are necessary truths always knowable a priori, or do they come apart?"},{"slug":"the-wittgenstein-rule-following-paradox","label":"The Wittgenstein rule-following paradox: is there a fact about what I mean by a word that fixes how I should apply it to new cases?"},{"slug":"vacuous-names-and-fictional-entities","label":"Vacuous names and fictional entities: do names like 'Sherlock Holmes' or 'Vulcan' refer to anything, and if so, to what?"},{"slug":"a-puzzle-about-belief","label":"A Puzzle about Belief: does Pierre believe that London is pretty? What does the case show about reference and belief?"}]}