On 11/8/15, Mark, Wes, and Dylan were rejoined by Matt Teichman to continue the thread of our ep. #126 on Saul Kripke. Our primary text was his 1975 article "The Meaning of Meaning," with secondary emphasis on his earlier, preparatory essays, "It Ain't Necessarily So" (1962) and "Is Semantics Possible?" (1970).
If Kripke was concerned primarily with debunking the descriptivist theory of meaning put forward by Russell (whose essay about this I will read to you) and Frege, Putnam concurs with this project (and Kripke was actually riffing off of Putnam's two earlier essays here) and then adds a positive theory of his own.
To remind you of some key terminology here, "meaning" is in analytic philosophy circles taken as having two components: these are the modern variants of Frege's "sense" and "reference." A term (let's consider just general class terms for simplicity here) has an extension, meaning its referents, the things in the world that it actually picks out, and its intension, which is something like a function for picking out things: a description. The common illustration for this is "creatures with hearts" and "creatures with kidneys." Apparently (so I read), these terms pick out all the same animals, so in that sense they mean the same thing, i.e., have the same extension. But in the more obvious sense, the terms obviously don't mean the same thing: they have different intensions. (So this doesn't mean "intention" like motivation, nor does it refer to an "intentional object" of consciousness like in Husserl and his friends.)
On the Frege/Russell theory of meaning, intension is some meaning we hold in our heads (which is not to say it's a psychological construct and different in each one of us; it's a public, linguistic thing, which is open for any of us to grasp, so my intension/Fregean sense will be the same as yours, even though we have different other psychological characteristics), and that intension determines what extension is being picked out. Think of intension as a function in mathematics: you would look at each thing in the world, and the function asks "is this a creature with kidneys?" and then the output of the function is "yes" or "no," and so after doing that, you get a set of the "yes" objects. That's the extension.
On Putnam's view of meaning, the situation is reversed, in that the extension comes first. Terms (per Kripke) don't use intensions to pick out extensions, but instead, reference is primary, so we use the word "sheep" just to refer to some set of animals. Maybe we don't even know that they're animals. We're pointing at a prototypical sheep or flock of sheep and use that word to refer to things that are like that. So the "that" there is a demonstrative, an act of pointing, aka an ostensive definition. Or, to use the example Kripke and Putnam talk most about, when we talk about water, we're talking about this stuff that runs in our rivers and streams, that falls from the sky in rain, and that we drink.
Kripke used modal language, language about possible worlds, to tease apart what goes into this act of meaning, and Putnam uses a similar thought experiment by talking about Twin Earth. Imagine that there's a planet somewhere in the actual world, right now, where the stuff that runs in rivers and streams, falls in rain, is safe to drink, and moreover tastes and otherwise looks just like water, is actually not H2O, but some other chemical compound, call it XYZ. And imagine we actually visit that planet and taste this XYZ stuff. Would we be correct in calling it "water"? Putnam and Kripke say no. When, on our earth, we refer to water, what we mean is "whatever it is that has the same underlying structure as this stuff." If Twin Earth people use the term "water" to refer to XYZ, they have the same idea in mind, i.e., "whatever has the same underlying structure as this stuff," but "this stuff" is pointing to different stuff, i.e., what runs in their rivers and streams. The technical term for this simple kind of relativism in language is "indexical." The word "I" is indexical, because though it in some sense means the same thing (has the same dictionary definition) whoever uses it, it changes referent depending on who's saying it. Ditto for "here," "this," "yesterday," etc. So Putnam is arguing that class terms have a hidden indexical character.
Because of this, we can say that (beyond the point I already made about Fregean senses/intensions being public, linguistic entities and not private psychological states, even if the actual grasping of an intension is of course a psychological act) that meanings are not in our head. We literally don't know what we mean when we say a term, because we're pointing at some objects in the external world, and we potentially don't know everything relevant about those objects. In our discussion, Matt brought up the term semantic externalism to capture this idea.
Putnam brings up more examples to make his point: Consider gold vs. fool's gold. At this point in history, we can perform a chemical analysis to distinguish the two (just as in our imagined scenario we could come to discover through a little science that H2O is different from XYZ despite their similar appearance). But what about before this test was invented? Did the meaning of the world "gold" before that point actually cover fool's gold as well? No, because again, "gold" referred to "whatever it is that has characteristics similar to this stuff."
To use this example to add more of what's new and positive in Putnam's take on meaning over and beyond anything Kripke said: How can we tell if someone actually knows how to use the term "gold," if that person is linguistically competent in this respect? Putnam says that we use a stereotype of gold, which sounds like the kind of definition that Russell thought served to determine reference (and recall from Kripke that a definition can fix reference in a given circumstance; it just doesn't determine meaning): Gold is a yellow, valuable metal. Now, that doesn't uniquely pick out gold, and in fact (I didn't know this before reading Putnam) gold is nearly white, not yellow, when pure, and only yellow in jewelry because there's copper in it too. So our stereotype can actually be wrong, and yet still serves its function to be the thing that we need to know to be counted as linguistically competent with the word.
Or think about a tiger: A tiger is a four-legged, large cat (and so an animal) with stripes. If that were the definition of tiger, then we would be worried about what to say about a three-legged tiger or a tiger that due to a skin problem had no stripes. But it's not; it's just a stereotype we use for talking about tigers. If a natural disaster were to occur wiping out all the tigers with stripes, leaving only those with the skin condition, then that would become the new norm. So these stereotypes change over time, and moreover, they are to some degree (and this is different from Kripke!) dependent upon our interests in discussing the thing. So "water" could in a chemical context refer only to pure H2O, so that if you actually collected a sample from a stream with the usual impurities, that wouldn't count as water in that context. Or if we were really only concerned with safe drinking with the usual taste, then in that case we might want to say that XYZ is water, or that fool's gold "works" as gold. What matters is the linguistic community and what its standards are for telling whether you understand the term, so that in the fabled Eskimo tribe with 20 words for snow, if you couldn't distinguish them, then members of that tribe wouldn't think you really knew what snow is, whereas we have no such requirements. This is edging into Putnam's pragmatism, which is a topic I really wanted to get into in this discussion (you'll note above that I didn't say what Putnam's response to Kripke's metaphysical claims was), but it's pretty tangential in "The Meaning of Meaning," and it just didn't happen. We'll just have to wait for another podcast to talk about that, presumably after we deal with Richard Rorty, with whom Putnam has substantial dialogue.
But to return to the topic and wrap this up, Putnam's theory of meaning is that to understand a term like "water," we have to understand:
- Its syntax (it's a noun)
- Its semantic markers (it's a natural kind, and liquid)
- Its stereotype (colorless, transparent, tasteless, thirst-quenching, etc.)
- and extension (H2O, give or take impurities)
If we take "meaning" to be "intension" (really, the term "intension" doesn't show up in Putnam's final theory), then the extension is one of four components that determine the intension. This, to recap, is reversed from Russell's claim that intension (qua description) determines extension.
Confusingly, Putnam uses the word "concept" to talk about a speaker's individual, subjective state of mind when using a term. So us speaking about water (H2O) and Twin Earth speakers about water (XYZ) both have the same concept (the same state of mind), but different intensions, because of the different extension involved.
"The Meaning of Meaning" and "Is Semantics Possible" are available in Putnam's Philosophical Papers, Vol. 2: Mind, Language and Reality. "It Ain't Necessarily So" is in Mathematics, Matter and Method (Philosophical Papers, Vol. 1).
Read "The Meaning of Meaning" online.
To get at the metaphysical/pragmatic issues mentioned above, I also read parts of his 1990 book Realism with a Human Face, which includes a recap of his agreements and disagreements with Kripke: "Is water H2O?"