So that means we have a relatively limited topic: What is the semantic meaning of proper names? What do names themselves mean? My name is "Larry" and presumably that word, "Larry," has meaning; so what is it? Youíd think that would be a fairly clear and straightforward question. Youíd think the question is not at all mysterious, since, for example, the name "Larry" means me! So I am the meaning of the name. That makes sense, right? Well, it may not be so simple. Weíre still not done considering complications.
I just got done alluding to a view about the meaning of proper names, which we can formulate as the following theory:
The referential theory of proper names is the view that the meaning of a proper name is the individual to which it refers (denotes, picks out).
Another name for the theory is the "Fido"-Fido theory -- because the name "Fido" refers to, or denotes, or picks out, well, that little dog Fido. So the name "Fido" means the dog Fido. But now wait a minute. Lots of dogs have been named "Fido." Lots of people have been named "Larry." The referential theory talks about proper names as though thereís only one thing that any proper name, such as "Fido," can mean. Right? It says: "the meaning of a proper name is the individual," that one item, "to which it refers." But then isnít that wrong, to say that a proper name like "Fido" can mean any one dog in particular?
Not really, because when we use proper names, we usually understand by the total context which individual weíre using the proper name to pick out. So when I said that the name "Larry" means me, you all understood, of course, that when I used the name "Larry" it meant one of the gazillions of guys named "Larry." But just to be clear, letís update the statement of the referential theory, so it includes this stuff about context. Weíll put it like this:
The referential theory of proper names is the view that the meaning of a given use of a proper name is the individual to which, in the context of the use, it refers (denotes, picks out).
So this is better. It might be the case that the name "Fido" picks out lots of different dogs; but a given use of the name refers to just one of the animals named "Fido."
I suppose this looks like a very reasonable theory. But consider now the following objection, which is due to the extremely influential German philosopher and logician, Gottlob Frege, who worked around the turn of the century. He wrote a famous article called "On Sense and Reference," in which he said that proper names have two different kinds of meaning: not only their reference, but also their sense. So Frege said that there was more to the meaning of proper names than what they referred to. You also have to consider their sense, he said.
Consider examples like the following. Suppose you know that the name "Cicero" refers to a famous ancient Roman statesman. Well if you didnít know that then you do now. Suppose I tell you next that the name "Tully" refers to an ancient philosopher who was also an orator. Iím sure most of you didnít know that. But now consider. If I were to tell you, "Cicero is Cicero," youíd say, "Yeah, so?" You havenít learned anything then. But if I tell you, "Cicero is Tully," then you have learned something -- and thatís a matter of fact, indeed Cicero is Tully; the manís full name was Marcus Tullius Cicero. Well, the argument goes, the only way it can be informative to say that Cicero is Tully is if the two names, "Cicero" and "Tully," differ somehow in their meanings. They have, as Frege said, different senses.
Let me give you another example. Both of the examples are totally hackneyed but if youíre going to get a traditional introduction to the theory of meaning then youíve got to be exposed to them! There is bright point of light which appears in the morning sky, just before sunrise, called "the Morning Star"; and similarly, just after sunset sometimes you can see a bright point of light in the sky, and this has been called "the Evening Star." And so the proper name, "the Morning Star," refers to a particular celestial object that appears the morning; and the proper name, "the Evening Star," refers to a particular celestial object that appears in the evening. And well, youíve probably guessed it -- in fact the Morning Star is the Evening Star, and they are both the planet Venus and not a star at all.
So youíve been informed and enlightened; youíve been told that the two different names actually refer to the same thing, and you (probably) didnít know that before. If the two names had exactly the same meaning, though, how could it be informative or enlightening to be told that the two names refer to the same thing? They couldnít. So "the Evening Star" must differ somehow in its meaning from "the Morning Star." Since they refer to the same thing, namely Venus, it must be something else about their meaning that differs. And this other thing we call sense. So the sense of "the Morning Star" differs from the sense of the "Evening Star." Frege then said that a proper name denotes its reference and expresses its sense.
So then what sort of thing is a sense? Itís basically like a description of a thing the word refers to; you can regard the following as a definition of "sense":
The sense of a proper name is a set of properties that can be expressed as a description that picks out the reference of the name.
To take an example: the sense of "the Morning Star" would be a set of properties that can be expressed as a description; and that description would pick out the planet Venus from among all the other stars and planets in the sky. So the description might be: "the brightest natural object in the sky, aside from the sun and the moon, which appears occasionally before sunrise." Something like that description would express the sense of "the Morning Star." And then how would the description of the sense of "the Evening Star" go? Maybe like this: "the brightest natural object in the sky, aside from the sun and the moon, which appears occasionally after sunset."
Now remember, we started out our discussion of proper names with the referential theory, the "Fido"-Fido Theory, which says that the meaning of a proper name is simply the thing to which it refers. But now if we say, with Frege and some others, that proper names have a sense as well as a reference, then we have to change our theory. So hereís the new theory:
The descriptivist theory of proper names is the view that the meaning of a given use of a proper name is constituted by (1) the individual to which, in the context of the use, it refers (denotes, picks out), and (2) a set of properties that can be expressed as a description that picks out the reference of the name. (1) is the reference and (2) is the sense.
So according to the descriptivist theory of meaning, thereís a description of the sense of proper names, and that description would, like a definition, pick out the reference of the proper name. In fact, if you will remember that distinction we drew between the extension and the intension of a general term; reference and sense is the same sort of distinction, only applied to proper names, rather than general terms. The extension of a general term like "dog" is just all the dogs that are out there; the extension is what the word can be used to refer to. The intension of a general term is basically a description of what all dogs have in common; itís what the definition expresses. So you can think of the sense of a proper name something like an identifying description of an individual -- as it were, a definition of a name. So the sense of my name, "Larry," would list some salient facts about me, that picked me out, that distinguished me from other people. And then to return to what the descriptivist theory of meaning says: it says that in order to say what the name "Larry" means, not only would you have to say that it means me; youíd also have to specify the sense of the name, that is, youíd have to give that identifying description of me.
Now, there have been a lot of philosophers who have denied that there is anything like a sense of proper names. Instead, they advocate the so-called causal theory, which Iíll define in a little bit. But first I want to say what the causal theorists deny. The causal theorists say: in order to give the meaning of a proper name, you donít have to express the sense; you donít have to give an identifying description of the individual that bears the name. They think that, in order to say what a name means, we can just stick with the referential theory; and then all you have to do is account for what causes proper names to refer to the individuals to which they refer. Why, they ask, does any given proper name refer to the individual that it does? So the causal theorists, the people who think that proper names donít have senses, still feel they have to ask: How do proper names come to refer to the individuals that they do refer to?
So how would a causal theorist answer that question? Well, something like this. In naming a newborn baby, traditionally we have taken the baby to a priest or pastor who baptizes and names the baby, say "Jane Doe." So the pastor says, "This childís name is ĎJane Doeí." And henceforth everyone calls the little girl "Jane." With that initial act, the act of christening as itís called, the pastor gives the girl her name. This seems all fairly straightforward. So we were asking: How do proper names come to refer to the individuals that they do refer to? In the case of our Jane, how does the name "Jane Doe" come to refer to Jane? The answer is obvious: Jane was christened "Jane."
However, not everyone who knows Jane was at Janeís christening. So how is it that when they use the name "Jane Doe," they are referring to Jane? Well, thatís obvious as well: there is a causal chain that passes from the original observers of Janeís christening to everyone who uses her name. For example, maybe Janeís friend Jill wasnít at the christening, but Jill learns Janeís name from Janeís mother, who was at the christening.
The causal theory says, then, that all proper names get their meaning -- their reference is fixed, made rigid as Kripke says -- by an initial act of christening. Whether youíre naming a person, a ship, a town, a planet, or whatever: thereís that original act of naming, and then the thing named has its name rigidly, so that the name is called a rigid designator of what it refers to. Thatís a technical term: rigid designator. Hereís a definition:
A name is a rigid designator iff it denotes its reference in all possible worlds.
So the name "Jane Doe" is a rigid designator; which means that it denotes Jane in all possible worlds. And what that means is that, throughout all kinds of possible changes that Jane might undergo, all the different ways that she is or might have been, the name will refer to her.
So then itís not the sense of the name "Jane," not any particular set of properties of Jane, that we use to refer to Jane. Because those properties might change -- they might have been totally different. But Jane would still be Jane. In fact, we can refer to Jane without knowing anything about her -- except the fact that sheís called Jane. So itís possible to refer to Jane without knowing anything like a sense of the name "Jane." And the reason, Kripke said, that thatís possible, is that there was that original baptismal act, when Jane was given her name; and in order for us to succeed in referring to her, there just has to be a causal chain leading from our present use of the name and that original baptism.
So if you want the causal theory of names stated briefly, here it is:
The causal theory of proper names is the view that the meaning of a given use of a proper name is constituted by the individual to which, in the context of the use, it refers (denotes, picks out); and the nameís reference is originally fixed by a baptismal act, whereupon the name becomes a rigid designator of the reference; and later uses of the name succeed in referring to the reference by being linked by a causal chain to that original baptismal act.
Well, I donít have time to say anything else about the theory of meaning. Iíve just given you a sample of one problem within the theory of meaning -- the problem of the meaning of proper names. This is to say nothing, or very little anyway, about the meaning of, for example, whole sentences.
But letís talk a little about the meaning of whole sentences, because our next topic is truth, and itís whole sentences that weíre going to want to say are true or not. That makes sense, right? Individual words and phrases arenít true or false; only whole sentences are true and false.
And not just any old sentences are candidates for truth; they have to be meaningful as well. You can take the following as a principle: "A sentence can be true or false only if it is meaningful." In other words, if a sentence is just nonsense, then it canít be either true or false. So thatís one very important connection between meaning and truth: being meaningful is a prerequisite of truth or of falsehood.
You might object, "Well, wait a minute. Hereís a nonsense sentence: ĎThe slithy toves did gyre and gimble in the wabe.í Why couldnít we just say that that is false?" Well, hereís why that nonsense sentence canít be false: if itís false then its opposite has to be true. Hereís another principle you can take home with you: "If P is false, then not-P is true." So just apply that principle to the nonsense sentence I gave you. We want to say "The slithy toves did gyre and gimble in the wabe" -- thatís our P -- is false. Well then, not-P must be true. So then it must be true that the slithy toves did not gyre and gimble in the wabe. Yes indeed, I strenuously insist, the slithy toves did not gyre and gimble! Nope! And if they did gyre or gimble it certainly wasnít in the wabe! Well, thatís just nonsense as you can see. So, in order to be true or false, as I said, a sentence has to be meaningful. And as I said, thatís a very important connection between the topics of meaning and truth.