The Trouble with Natural Kinds: Putnam’s Version

This post is a continuation of my posts on natrual kinds; see my take on Quine’s account of kinds, and my twoparter on Kripke’s account of kinds.

Putnam’s views on issues of metaphysics and language have actually evolved extensively over time, and his main arguments for realism about natural kinds, which I’ll present here, do not accurately represent his views now, or for that matter, any time since about 1980. “Internal realism,” his current (last I checked) ontology, is extremely nuanced, and I’m not going to talk about it right here. Instead, the opponent whose arguments for natural kinds realism is, specifically, the Putnam of the 1970s. Putnam, in my opinion, deserves great respect for being one of the few philosophers to be completely forthright about changing his mind; he freely admits that his metaphysics has changed dramatically and that, in his opinion, his earlier incarnation was simply wrong.

Why investigate views whose own author has repudiated? The fact is, most of the philosophical community doesn’t agree with Putnam about his own earlier theories. I’d estimate that, currently, the hardcore scientific realist Putnam of the 1970s has more adherents than the internal realist of the 1980s and beyond.

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The Trouble with Natural Kinds: Kripke’s Version, Part 2

In this post, I argued that, contra Kripke, when the baptismal origin of a natural kind term has none of the properties we associate with that term, the term no longer refers to a kind that includes its baptismal origin. I then promised that I argue that, when objects not “of the same kind” (in a realist sense) as the baptismal origin of a natural kind term have all of the properties associated with a kind term, the kind term does (or at least, Kripke didn’t show that it doesn’t) include those objects in its extension. Here’s where I’ll do that.

Kripke’s Original Argument

Kripke’s example is as follows: Consider English as it was spoken pre-Lavoisier. The term “water,” at that point, clearly did not have associated with it the property of having the chemical formula H2O. The set of properties associated with it, at most, involved those properties accessible to people at the time. Now, suppose there was another compound (which Kripke calls XYZ), such that it had all of the properties of water that were accessible to people before the start of modern chemistry.

Kripke takes it as obvious (and I’m pretty much inclined to agree) that XYZ shouldn’t count as water. But should it count as water as the term was used before the start of modern chemistry? Kripke thinks that’s pretty obvious, too. Of course, he claims, the meaning of “water” hasn’t actually changed since the 17th century. So XYZ couldn’t have counted as “water” then, either, even though it had all the properties that were associated with the term.

Continue reading The Trouble with Natural Kinds: Kripke’s Version, Part 2

The Trouble with Natural Kinds: Kripke’s Version

Unlike my attack on Quine’s argument for natural kinds realism, my problems with Kripke’s natural kinds realism did make it into my dissertaion. My focus there wasn’t on natural kinds; it was, instead, on Kripke’s general theory of non-connotativity of certain terms (and natural kind terms are among them). But, at least for Kripke, non-connotativity of natural kind terms and natural kinds realism are closely tied, so the same argument will do for both. For those of you who aren’t terribly excited about the idea of looking up my dissertation, I’ll put a somewhat abridged version of my argument here.

Kripke’s Original Argument

Kripke’s argument for natural kinds realism is, essentially, this: We don’t specify, through anything like definition, the extensions of our natural kind terms. For example (his example), there’s no set of concepts associated with the term “tiger” that uniquely picks out all and only tigers. Indeed, tigers could turn out to have none of the attributes associated with our concepts of them. Although they, for example, appear to eat meat, be related to cats, and be striped, these could (though it’s exceptionally implausible–it’s not impossible, and that’s all he needs) turn out to have none of these attributes. The apparent relation to cats could be a result of our inadequate understanding of genetics, the stripedness could be an optical illusion, and the meat-eating could in fact be something very different (perhaps–remember, we’re allowing the implausible here–tigers’ claws convert the creatures they kill into 100% textured tofu, so they never consume an iota of meat).

(Kripke has another argument, about water, that goes in the other direction–that something can have all the properties we conceptually associate with a kind without being a member of the kind.  I’ll cover that in a separate post.)

How do natural kind terms get their extensions? Well, Kripke wants to present, as opposed to a conceptual model, a causal model. The initial referent of “tiger” (or, more likely, some linguistic ancestor of “tiger”) was a tiger because of something that Kripke called a “baptismal event”–generally an ostention (“I shall call that thing [pointing] a tiger”) but possibly an *initial* description (“I shall call the creature that mauled this water buffalo a tiger”). At any rate, in all likielihood, this baptismal event picked out only a single object, or possibly a small number of objects. The relationship of that term  to other tigers is that other tigers are part of the same natural kind. The extent of that natural kind is a scientific fact to be discovered, not a definitional one to be stipulated. And the relationship of our term “tiger” to tigers is that there’s the right sort of “causal chain” between the initial term’s usage and our current usage of “tiger.”

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