On 10/11/15 we were rejoined by Elucidations' Matt Teichman to talk about one of the most readable yet still very weird texts in the canon of analytic philosophy, Saul Kripke's Naming and Necessity, which is a series of three lectures from 1972, adapted into a book that was published in 1980.
It starts off talking about a topic that seems obscure: Why do words refer to the things they do? Well, social convention, of course. But how does the referring actually happen? Is it because when you use a word, you have an image in your head of the thing? Do you have some description of the thing in mind, and is that mental content what makes it refer?
According to Aristotle, a definition of a thing is a series of necessary and sufficient conditions, i.e., a description that uniquely picks out that kind of thing and conveys its essence. One way to think about essences that was in vogue by Kripke's time is to ask "if in some possible world, the thing I'm thinking of didn't have that quality, would it still be the same kind of thing?" Like if you say that man is a rational animal, then if you think about a world where people weren't animals, or rather the things that look and act like people (androids?) weren't actually animals, would they still be people? If "animality" is really an essential property of man, then you'd have to say no, even if they look like people, they're not people, not "man."
So it was a common view, spelled out for one by J.S. Mill, that you can analyze a class term like "human" into a definition, and that having that definition in mind is what makes you correctly refer to that class. But what about proper names, i.e., individuals, not classes? Mill thought that those did not involve descriptions, but simply referred to that specific individual, so that "Mark Linsenmayer" doesn't mean "the host of the Partially Examined Life" or anything like that, but just refers to me. But what about cases where a name has no referent, like "Santa Claus" or "King Unicorn?" If the meaning of a name is just the individual referred to, then those names would have no meaning at all. Or what about "Borat" and "Ali G?" If those names both just meant that comedian Sacha Baron Cohen, and having that meaning in mind is the only way to successfully refer to that individual, then ignorant people interviewed by one of Cohen's comic personas couldn't successfully refer to that guy at all.
Because of this, Gottlob Frege (listen to our episode on this topic) distinguished between the referent of a name and its "sense," so that Ali G and Borat and Bruno could all be different senses of the same referent. Bertrand Russell tried to make the notion of sense concrete by turning it into a descriptive phrase (PEL Citizens can listen to me read his 1905 article "On Denoting" where he lays this out). So, maybe when you refer to Aristotle, you have in mind "the student of Plato and teacher of Alexander the Great that wrote the Metaphysics, Politics, etc."
But what if Aristotle hadn't actually taught Alexander? He would still be Aristotle, right? It's not true by the definition of "Aristotle" that he did this particular thing. Later descriptivists (Kripke mentions Wittgenstein among others) thought that, well, it's not a specific definition like this, but a cluster of properties. If we imagine a possible world where some guy did most (the majority? some important ones?) of those things, then that's Aristotle.
Kripke denies all forms of descriptivism. Even if, in an imagined alternate history (that's all a possible world is: a counterfactual, not some alleged parallel universe) Aristotle hadn't done any of the things we attribute to him, the word Aristotle, spoken by us now about that situation, would still refer to that guy. Kripke agrees with Mill, then, that names do not pick out individuals via some description, but just directly. Some particular description might be used to fix the referent in our minds, but the referent is just that thing, and that description wouldn't be part of the meaning of the name.
Kripke even extends this beyond names (unlike Mill) to class terms. As soon as we came up with the idea of "man" (i.e., people), then we were referring to that species, whatever characteristics science or philosophy may discover that that species ends up having. Kripke thinks that gives us license to speculate à la Aristotle about essential properties: He would rule that the correct description of the possible world in which the bipeds walking around and talking that are actually androids is not that in that world people are androids, but that in that world there are no people at all, because an essential quality of "man" (you can translate that to "humans" instead of "people" if you prefer) is that they're animals. (He's not willing to follow Aristotle about the rational part, or at least doesn't say this; he's more interested in essential properties as discovered by science.) Whether or not you agree with any of Kripke's particular judgments about what properties of what types of things are essential, you can still buy the idea that this kind of talk is philosophically respectable: Kripke is seen as ushering in a new wave of doing actual metaphysics in this way, instead of just talking about the meanings of words à la the followers of Wittgenstein.
With this point about philosophy of language made, i.e., that words do not refer via descriptions, he uses this talk of possible worlds, also called modal language, e.g., modal words include "must," and "could," to make some interesting points about important identity claims in science. To start with, we're all familiar, pre-scientifically, with water, but it was a discovery that water is in fact H2O. So you might think that before that discovery was made, it was possible that water might have turned out to be some other compound. For Kripke, this confuses metaphysics (the way things are) with epistemology (what we know or don't know about them). If you mean by "possible" metaphysical possibility, then no, given that water is in fact H2O, then it has to be H2O. Think of a possible world: It's one where there is stuff running in rivers and streams, and people drink it, and it's clear, etc., but it's a different compound. Is that a world in which water is not H2O? No, says Kripke, that's a world in which there just isn't any water, but this other stuff instead; his verdict is exactly parallel to my example about the androids.
He gives a similar example re: heat (whatever it is that causes our sensation of heat) and the movement of molecules. In a possible world where creatures like us have that sensation of heat caused by something else, Kripke thinks that it's not that heat itself is no longer properly analyzed as the motion of molecules, but, as I just said in setting up the situation, that people's sensations of heat are caused by something other than what we call heat. It doesn't matter in this circumstance what the people in that world call it; we're reflecting on our shared intuitions about heat, or about water or Aristotle or man or whatever else. He thinks that what he's capturing through his examples is the way that we in fact think and talk about possibility. In that sense, it looks like he is doing philosophy of language or conceptual analysis much like Wittgenstein. But he would claim that he's not talking about language, but instead about the things that language talks about, i.e., about reality.
Lastly, Kripke takes a look at the claim that the mind just is the body. As with other scientific identities (per the above argument), if it's true at all, it's true in all possible worlds, necessarily true. Let's say we discover that some particular brain state in people is correlated with pain. Can we say then that the brain state is the pain? It seems on the face of it that we can imagine cases in which, someone feels a sensation of pain without having that particular brain state. Maybe they're aliens, with very different kinds of brains. Would we really want to say that such creatures necessarily couldn't feel pain at all?
If the identity theorist is right, we have to somehow rule out those imagined possible worlds as legitimate possibilities. It would have to be like the case with heat: We'd have to say that in such a world, the aliens might have something like pain, but it wouldn't actually be pain. But unlike heat, pain actually refers to a feeling. If those creatures had this feeling, then (according to our intuitions as Kripke sees them) they have pain, actual pain, just with some different underlying physical structure. Therefore, pain is not identical to a particular type of brain state.
Now, in the discussion, we didn't really have time after going through all the above to really try to respond to Kripke on this point. I personally don't think our modal intuitions are anywhere near as clear as Kripke thinks: I don't think our intuitions tell us for sure that the androids in the alternate world aren't in that circumstance "man" or that the non-H2O stuff that nonetheless flows and nourishes shouldn't still be called "water" by us, in which case you'd have to say that water is a functional concept, i.e., water is whatever it is that has that appearance and nourishes us, etc., and so there's no sense in saying that it essentially has the properties that science discovers it does in fact have. I might go so far as to deny this whole line of modal inquiry as irrelevant: as telling us nothing about the world, but only, at best, about the cultural assumptions buried in our psychology and/or our language.
Conversely, I see no strong reason to agree with Kripke that in the alternate world, the differently-brained-beings still definitely feel what we call "pain" as opposed something phenomenally similar to pain, which, due exactly to its being underlain by different stuff, we'd really want to call "shmain" instead. It seems to be an arbitrary decision whether we go with Kripke's view or this alternate verdict, because I don't believe our intuitions extend to far-out hypothetical situations in this way, as any good reader of Wittgenstein should know.
Regardless, Kripke's treatment of possible-world-talk is eminently reasonable as this type of talk goes, and if you want a glimpse of how philosophers talk about this kind of thing, as opposed to sci-fi authors, then this is a great place to start, and certainly the question he brings up about the status of scientific identities is absolutely central in philosophy of science, and insofar as I want to admit modal talk at all, I definitely agree that scientific identities are necessary ones: that if water is in fact H2O, then it's necessarily H2O and it doesn't really make sense to say that it could have turned out to be something else, though it's correct that before the discovery, so far as we knew, it could have been something else. This distinction between metaphysics and epistemology seems to be very clear and important.
Here's one response by some identity theorists (by Ned Block and Robert Stalnaker) to Kripke's claim that mind and brain can't be necessarily equal (and so can't be equal at all).