Reflexivity, Indexicality and Names

Reflexivity, Indexicality and Names John Perry [In Direct Reference, Indexicality and Proposition Attitudes edited by Wofgang Kunne, Martin Anduschus, and Albert Newen. Stanford, CA: CSLI-Cambridge University Press, 1997.] 1 Introduction Consider: (1) “I am a computer scientist.” (said by David Israel) (2) “David is a computer scientist.” (said by someone who is referring to David Israel with “David”) It has been persuasively argued by David Kaplan and others that the proposition expressed by statements like (1) is a singular proposition, true in just those worlds in which a certain person, David Israel, is a computer scientist. Call this proposition P . The truth of this proposition does not require that the utterance (1) occur, or even that Israel has ever said anything at all. Marcus, Donnellan, Kripke and others have persuasively argued for a view of proper names that, put in Kaplan’s terms and applied to this example, implies that the proposition expressed by (2) is also simply P .1 The thesis that expressions of a certain category (names, indexicals, demonstra- tives, pronouns, descriptions, etc.) are referential 2holds that these expressions con- tribute the object to which they refer, rather than a mode of presentation of that object, to the propositions expressed by statements containing them. The thesis that indexicals and names are referential creates the challenge of explaining the difference in cognitive significance between statements like (1) and (2), that express the same proposition[Wettstein, 1986]. The problem has two parts, which 1[Marcus, 1961], [Donnellan, 1970],[Kripke, 1980] 2David Kaplan’s term is directly referential. Kaplan has a precise concept of “directness” in mind, but unless one is focusing on his exact words, the term “directly” is likely to suggest that there is no semantic mechanism intervening between the expression and its referent. This is pretty clearly not the case with indexicals, as Kaplan’s own analysis shows; it may be more plausible for proper names. Using terminology introduces in Section 3 we can say: Kaplan’s language suggests that directly referential terms name,butwhat he really says is simply that they refer. 1 I’ll call “cognitive motivation” and “cognitive impact”. The problem of cognitive motivation is that in many circumstances, the beliefs and desires that might lead a competent user of English to assert (1) differ from those that might lead one to assert (2). The problem of cognitive impact is that in many circumstances the beliefs and desires a competent listener would acquire (and would be expected to acquire) from hearing (1) differ from those she would acquire from hearing (2). If (1) and (2) express exactly the same proposition, why should this be so? Let’s look at our example in some detail. First note that differences in David’s beliefs might lead him to assert (1) rather than (2) or vice versa. Suppose David has amnesia. He might have figured out what his profession was, but not have remembered his name. Then he would be in a position to assert (1) but not (2). Or he might have figured out that a certain person, David Israel, was a computer scientist, without realizing that he is that person. Then he would be in a position to assert (2) but not (1). In the normal case, in which David does not have amnesia, differences in desire could motivate him to assert (1) rather than (2), or vice versa. In normal circumstances, if Israel wants to tell someone his profession, he will use (1) and not (2). Suppose, for example, that David has made some interesting points following a paper by a guest lecturer at CSLI. After the session he chats with the speaker, who seems unsure that he can trust what David says about programming languages. It would be natural for David to say (1), and odd for him to say (2). He wants to reassure his interlocutor about the reliability of what he says about programming languages. (1) will do that; (2) might not. I’ll call this example Case 1. There are easily imaginable circumstances in which David’s desires would lead him to use (2) but not (1). Suppose a government bureaucrat has the job of identifying computer scientists, who will then be sent a letter offering a well-paid job building the Information Highway. The bureaucrat himself has a clear antipathy towards computer scientists. He reads David names from a list of people who work at SRI and asks if they were then or ever had been computer scientists. When he gets to “David Israel”, Israel might just say (2), figuring that the information that he was the person in question was simply irrelevant and would lead the bureaucrat to be rude to him. Here David would not want his interlocutor to know that he, the person being talked to, was a computer scientist but he would want him to know the individual who is designated by the token of “David Israel” on the list is a computer scientist. He thinks that he will pass on that information with (2). I’ll call this Case 2. Given that David knows that he is David Israel, his choice between (1) and (2) is based on the effect he wants his utterance to have on the beliefs of his interlocutor— what I am calling its “cognitive impact”. He thinks that if he utters (1), his interlocutor will realize that the person he is talking to is a computer scientist. If he utters (2), his interlocutor might not realize that, even if he believes what David says. In fact Israel is well-known as a computer scientist, but looks and acts more like a philosopher. A competent speaker who hears (1) may well be skeptical about what he hears, even though he readily assents to (2), or even asserts it himself, having read articles by Israel. How is this difference possible, if the propositions expressed by (1) and (2) are the same? 2 My thesis in this paper is that to understand the difference in cognitive significance between (1) and (2), we need to acknowledge several different kinds of content.The paper develops a line of argument put forward in the later papers of [Perry, 1993]. In those papers a distinction is made between reflexive and incremental content, and it is argued that the former is relevant to cognitive significance. This distinction is most intuitive in the case of indexicals. In this paper I show how the basic idea can be ex- tended to deal with proper names, without treating them as if they were indexicals. This requires examining the difference between reflexivity and indexicality, and explaining how the concept of reflexivity can be applied to expressions that are not indexicals. But I will start with indexicals, and then move to consider names. 2 Indexicals (A) captures most of what a competent English speaker knows about the word “I”: (A) A use u of “I” designates x iff x is the speaker of u. From this, we see that (1), will be true iff Q:Thereisanxsuch that i) x is the speaker of (1); ii) x is a computer scientist. Q is not the proposition expressed by (1); as we saw, that is P . The truth values of P and Q will agree in the actual world, but may disagree in other possible worlds. In the worlds in which Israel is a computer scientist, but does not utter (1), P is true and Q is false. This does not mean that Q is irrelevant to the cognitive significance of (1), however. Q gives us what a competent user of English who hears (1) will know, just on the basis of those facts, about its truth conditions. Someone who knows English and hears (1), but isn’t in a position to see who said it, would still realize that Q captured the conditions under which it was true. Such a person might express this knowledge by saying “This utterance is true, iff its speaker is a computer scientist.” The truth conditions he associates with (1) are reflexive in that Q is about the utterance (1) itself. Because he doesn’t know who the speaker is, he cannot “detach” the truth conditions of (1) from (1) itself. In contrast, someone who learns that Israel is the speaker of (1), can get at the truth conditions of (1) in a non-reflexive way: “This utterance is true iff Israel is a computer scientist.” I call this the incremental truth conditions of (1), given that Israel is the speaker. “Incremental” is used here in the sense of “additional”. Given that Israel is the speaker of u,whatmore hastobetrueforuto be true? Answer: Israel has to be a computer scientist. This is just the proposition P , the proposition expressed by both (1) and (2). The incremental truth conditions correspond to the ordinary philosophical concept of truth conditions; they are what is said by the speaker of the utterance. I’ll also call this “official content”. 3 The difference between Cases 1 and 2 above has to do with the mode of presentation that Israel wanted his hearer to associate with the belief that he was a computer scientist. In Case 1, Israel wanted the hearer to recognize that the person spoken about was also the person speaking. The plan of understanding that he has in mind goes roughly like this: The hearer will perceive my utterance, and, as a competent speaker of En- glish will recognize that it is true iff the person who makes it is a computer scientist (Q). He will also see that I, the person in front of him and talking to him, is the speaker of the utterance.

Load more