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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.”


The Thing I Love About Technology

…is how it makes our lives so much easier.

So, I think Dreamhost, or possibly WordPress, has done something that made my contact form stop sending me email. Problem is, I’m not sure *when* this happened; I have, at least, some hits on the contact form that didn’t result in my receiving any emails.


  1. Best not to use the contact form for now. If you want to contact me, and you don’t want to do it via a comment, email me directly (see below).
  2. If you’ve already used the contact form to contact me, and you haven’t received a reply, I’m really, really sorry–I think your email got lost in the void. If it’s not wildly inconvenient, please resend, again by emailing me directly (see below).

My email address:  My first name <at> avromroyfaderman <dot> com. Again, my apologies.

A Sinking Feeling

Songwriters, I’m sure, know it well, that tweak of deja vu when they listen to their last hook. It seems familiar, they think to themselves. Does it just seem familiar because I’ve been playing it so much, or is it that it’s an advertising jingle I heard when I was three?

At any rate, I’ve been having that same sinking feeling when I read back over my last two posts on decision theory. The arguments seem somehow…familiar, and I’m not quite sure if it’s just that they seem natural and right to me, or that <shudder> I’ve seen the arguments somewhere before. I’ve been out of this game for ten years, and I worry that, if you know what I mean, I remember more than I remember that I remember. A cursory search, which is all I can really do as a non-academic, has turned up nothing, and I certainly can’t for the life of me place where I might have heard them, but, you know. I worry.

At any rate, this is a plea: If you believe that in either of those posts, or in any post in this blog, I’m using the ideas of others without properly crediting them, please let me know. You can comment on the post, or you can contact me directly. I have far, far less than no interest in plagiarizing anyone, and promise that I will never do so intentionally. If I do so unintentionally, I hope that, with your help, I can set the record straight and make amends.

At any rate, enough paranoia. Back to your regularly scheduled blog.

Dealing with Asymmetric Death in Damascus

So, I’ve been obsessed lately with a couple of really good posts over on Thoughts, Arguments, and Rants about decision theory. In particular, there’s this post about a game Brian Weatherson calls (for reasons that are clear if you read the post) “Asymmetric Death in Damascus.”

Weatherson’s Original Example

Here’s a quick summary of the game. Predictor has placed money in two boxes, and gives you a choice of picking Box A or picking Box B. (He hates mixed strategies, so won’t put any money in the boxes if he thinks you’re going to use one). He allocates the money as follows:

  • If he predicts you’re going to choose Box A, he puts $100 in A and $1400 in B.
  • If he predicts you’re going to choose Box B, he puts $800 in A and $700 in B.

Now, I think there’s an obvious right choice here–box B. Note that the standard “two-boxing” argument doesn’t argue for either A or B, and the standard “one- boxing” argument argues for B. But as Weatherson points out, there’s a problem with following the “one-boxing” argument: one-boxing arguments don’t work.

Still, though, the intuitive pull of Box B is pretty strong here. And note that, while Weatherson demolishes the argument that chosing Box B is rational (at least for us two-boxers out there), he doesn’t actually present an argument that it’s not rational. It’s just that the standard techniques (such as ratifiability) available to two-boxers don’t endorse it.

What would be really cool is if we had a plausible general account of rational decisions that mandated two-boxing in Newcomb’s paradox, but also mandated picking Box B in Asymmetric Death in Damascus (and, dare we dream, ensured that any game with a finite set of choices had at least one rational choice?). And I think I do.


A Stronger Claim about Projectability

So, I recently wrote a post that was intended to be an attack on Quine’s argument for natural kinds. And tucked away in the very last paragraph, I think I put the most important statement of the post: It’s really not just an attack on Quine’s argument. It’s an attack on a much more general strategy for solving Goodman’s Paradox. I want to make a separate post to call that out–so here it is.

The real thrust of the arguent is that projectability is not a property of predicates. To give you an idea of how realatively broad that is, I’ll note that not only is it a refutation of Quine’s solution to Goodman’s Paradox, it’s also a refutation of Goodman’s own (radically different) solution. Whether the account of projectability is as realist as Quine’s “Projectable claims involve natural kinds” or as constructivist as Goodman’s “Projectable claims involve entrenched predicates,” if you think that you can pick out a unary property of predicates that allows them to participate in projectable claims, I think you’re going to run into trouble with my argument.