Meaning, as I shall use the term, is a property of expressions--that is of types rather than tokens or utterances. Meaning is what is fixed by the conventions for the use of expressions that we learn when we learn a language. In contrast, content is a property of individual utterances. Content is tied to truth-conditions. The content of a statement--a specific use of a declarative sentence--is a proposition that embodies its truth-conditions. The contents of utterances of subsentential expressions--terms and predicates--is the contribution they make to truth-conditions; it's the things that utterances of names designate and the conditions expressed by utterances of predicates and definite descriptions.
Any part of speech can have an indexical element, but I'll focus on the role of such expressions as ``I'' and ``you'' and ``that man'' in simple statements. This will allow us to compare indexicals with the categories of expression most studied in the philosophy of language: proper names and definite descriptions--phrases of the form the so and so.
First I need to make some distinctions and develop some concepts about propositions. I will not need to adopt a specific and detailed ontology of propositions and their components for the purposes of this essay. There are two main approaches to propositions in the literature today, the classic conception of a proposition as a set of possible worlds, and a number of conceptions of structured propositions. I'll think of propositions structurally, but borrow the possible worlds conception when convenient to get clear about things. The distinctions I need can be made in any number of more detailed approaches.
Consider:
(1) is a statement of mine, referring to my son Jim Perry and to Lincoln, Nebraska. On the now standard view of proper names (which I'll discuss below), (1) expresses a singular proposition, a proposition that is about Jim himself and Lincoln itself, rather than any descriptions or attributes of them. In some of the possible worlds in which this proposition is true Jim will not be named ``Jim''; in some he will look different than he in fact does, act differently than he in fact does, have a different job than he in fact has, and so forth. And in some of the worlds Lincoln may be named ``Davis'' or ``McClellan'' and may not be the capital of Nebraska. As long as Jim was born in Lincoln in a given world then the proposition is true in that world, whatever he is like and whatever he is called in that world, and whatever Lincoln is like and whatever it is called.
On the possible worlds conception of propositions, this proposition just is the set of worlds in which Jim was born in Lincoln. On a structural conception of propositions, one could think of the proposition expressed by (1) as an ordered pair of a sequence of objects and a condition:
Jim Perry, Lincoln 
, x was born in 
Such propositions are true if the sequences of objects in the first member of the pair meets the condition that is the second member. It is natural to say that Jim himself is a constituent of the proposition, on the structural conception. Although on the this conception we don't identify the proposition with a set of worlds, it is still natural to talk about the worlds in which it is true.
In fact, Jim is the manager of Kinko's
, and Lincoln is the
capital of Nebraska. So consider,
On the standard account of definite descriptions,
(2) expresses a general proposition, a proposition
that is not specifically about Jim and Lincoln, but about
being the manager of Kinko's, and being the capital of
Nebraska. This proposition is true in worlds in which
someone--it doesn't have to be Jim--is the manager of
Kinko's and some city--it doesn't have to be Lincoln--is
the capital of Nebraska, and the someone was born in the
city. Consider the possible world in which Omaha is the
capital of Nebraska, and Marlon Brando or Henry Fonda or
Saul Kripke or some other native Omahan manages the Kinko's in Lincoln. In these
worlds (2) would be true, wherever my son might be born.
Let a mode of presentation be a condition that has uniqueness built into it, so that at most one thing can meet it, such as x is the manager of Kinko's or x is the capital of Nebraska. We can think of the proposition expressed by (2) as an ordered pair of a sequence of modes of presentation and a condition:
x is the manager of Kinko's, y is the
capital of Nebraska , x was born in
The distinction between singular and general propositions is helpful, but a bit too simple. Consider,
This would usually be called a singular proposition; being singular is sort of a dominant characteristic, so that if at least one argument role of a condition is filled by an object, the result is singular even if the other argument roles are filled by modes of presentation. I will speak this way, but we have to keep in mind that the basic concept is that of an argument role being filled either by an object or by a mode of presentation of an object.
Now consider,
(4) and (5) express conditions rather than propositions. But we need to draw a distinction between them. (4) is a singular condition, because it incorporates the city, Lincoln, as a constituent, while (5) is a general condition, with the modes of presentation, y is the capital of Nebraska as a constituent.
For our final point, look closely at (2). (2) expresses a general proposition--both argument roles of the condition x was born in y are filled by modes of presentation. But these modes of presentation themselves are singular, involving Kinko's and Nebraska as constituents, respectively. I'll say that a proposition or condition is purely qualitative if as one goes down through the hierarchy of conditions involved in it, one never encounters an object, only more conditions. I'll call it lumpy if one encounters an object. The proposition expressed by (2), though general, is lumpy.
Now compare
I use ``designate'' as a general word for the relations between singular terms and the objects they stand for. Thus the subject terms of both (1) and (6) designate the same person, Jim Perry. Both (1) and (6) assert the same thing of the same person, and in that sense (1) and (6) have the same truth conditions.
In spite of this, (1) and (6) are quite different, because
the singular terms in them work quite differently. I'll
express this difference by saying ``Jim'',
the name in (1), names and refers to
Jim Perry, but neither denotes nor describes
him. ``The manager of Kinko's'' denotes and
describes him, but neither names him nor
refers to him. Let me explain these terms.
Definite descriptions and names have quite different sorts of meaning. Language associates definite descriptions with modes of presentation. Definite descriptions are only indirectly associated with the objects they designate, as the objects that meet the mode of presentation associated by meaning. So, in virtue of its meaning, ``The manager of Kinko's '' is associated with a certain mode of presentation. It designates Jim Perry not simply in virtue of its meaning, but in virtue of its meaning and his job.
With names it is quite different. The convention I invoke, when I use
``Jim'' to refer to my oldest son, is not a convention that associates the
name with a condition which, as it happens, he fulfills. It's just a
convention that says that ``Jim'' is his name--a convention
established when he was born and that name was used on the
birth certificate.
There are then two quite different forms an answer to the question ``Why does term t designate object a,'' may take:
I use the terms denoting for the form of designation corresponding to the first, two part, answer, and the term naming for the form of designation corresponding to the second, one part, answer.
Our second distinction has to do with the contribution terms make to what I shall call ``the official content'' of a statement. The official content of a statement is what we would take the speaker as having asserted or said, or, as it is sometimes put, ``what is said'' by the statement.
On standard accounts, at least, the official contents of (1) and (6) are different. The proposition expressed by (1) is a singular proposition about Jim, while that expressed by (6) is a general proposition about being the manager of Kinko's. As we saw above, these are different propositions, true in different possible worlds.
I use ``refers'' and ``describes'' to mark this
distinction. These terms pertain to the contribution a
term makes to the official content of statements of which
it is a part. Names refer; that is, they contribute to
official content the individual they
designate. Definite descriptions describe;
that is, they contribute to official content the mode of presentation their
meaning associates with them.
If we ignore indexicals, confining our attention to names
and definite descriptions, our two distinctions line up, and may seem
to amount to the same thing. Definite descriptions denote and
describe, names name and refer. But in the case of
indexicals the distinction is needed. For as we shall see,
indexicals are like definite descriptions in that they denote, but
like names in that they refer.