It is afternoon and I am sitting in a hotel room in Mexico City. (The first sentence should actually have read: "It was afternoon and I was sitting at a desk in a hotel room in Mexico City," but who wants to split hairs?) My mind seems to be working well, but I am not at all sure in which fashion I should start filling up the page of hotel stationary waiting in front of me. Finally, I select as the subject of my first sentence, my most recent act and I write: "I have just set this cigarette in that ashtray." I then add three variations:

I have just set this cigarette in this ashtray.

I have just set that cigarette in that ashtray.

I have just set that cigarette in this ashtray.

While I am writing these sentences, across the 19th-century park in front of the hotel there is a demonstration in progress. What is important to me about the demonstration is that I choose not to watch it, preferring to stay inside this curtained room, scratching at this page. It, the demonstration, matters to me, but only as an event I choose not to attend, even as a spectator. There is something shameful in my even mentioning it here. I would do much better to mention the book about Sartre I was just reading.

That book about Sartre I was just reading is sitting across the room from this desk. In a treacherous world, one of the few things I am certain of is that this desk will remain this desk as long as I am sitting at it, though later, when I will be across the room reading that book about Sartre, this desk will become that desk, as that book about Sartre will become this book about Sartre. Would it be wrong to conclude from this that the difference between this and that is approximately 15 feet?

In the interval between cigarettes, let us suppose that there are two ashtrays on this table. Although they are separated by no more than a few inches, I would refer to them as "this ashtray" and "that ashtray." In fact, we needn't go to the trouble of supposing a second ashtray - there is one already available across the room. If I wished I could bring it over to this desk and place it next to this ashtray. Note: while I was on the other side of the room getting that ashtray, "this desk" would have become "that desk," "this ashtray" would have become "that ashtray" and "that ashtray" would have become "this ashtray." When I would have placed both ashtrays on this desk, I would have to remain attentive or otherwise risk experiencing a vertiginous exchange of articles between them.

I have lit another cigarette and placed it in the ashtray. I do not know why the object that a moment ago was "this ashtray" has now become "that ashtray." It must have something to do with the cigarette. I take a drag on the cigarette and try to imagine conditions under which this desk could become that desk, without me moving away from it. It would not be sufficient to posit the presence of a second desk in the room. No, what I would have to do would be to gaze at this desk as if it were the first one I had ever seen and say: "why, look at that . . . desk!" (Which reminds me of someone I once knew who often used to refer to books she admired, but wished to distance herself from because they were such obvious objects of admiration (at least I think this was her motive), as "that book by X." For example, she would say, "Have you read that book by William Gass?" and I would instantly know that she was referring to On Being Blue, which had just come out.) "This desk" might also become "that desk" were I to include it in a list of the things around me (this ashtray, that pack of cigarettes, these matches, that desk, this page) but this would only be an arbitrary shifting of articles.

I have an appointment to meet someone soon, so I had better start formulating some conclusions. The placement of these articles (this/that, these/those) is generally determined by the object's relative distance from the speaker. We are thus supplied with a basic method of categorizing the world, a method which separates the less intimate from the more intimate, joining us to certain phenomena, dividing us from others. Unexpectedly, the despotic categorization effected through these small words is what makes solidarity possible. Let us suppose, lighting another cigarette, the existence of a book from which the words this and that were excluded. (A helicopter just flew over the hotel.) I suspect that their absence would render the book unbearably impersonal. The author would have to use words like one, the and a. The world would be pushed ever farther away:

This ashtray is made of glass.

That ashtray is made of glass.

The ashtray is made of glass.

An ashtray is made of glass.

(Another helicopter just flew past, very low.) For the people marching on the other side of the 19th-century park, "that demonstration" is "this demonstration." In a few minutes, having demonstrated (I can also use the word for what I'm doing) perhaps nothing more than my own predilection for the sound of the letter T (this, that, cigarette, Sartre), I will have to leave this desk to go meet someone in the hotel bar. There isn't enough time to do anything about the space between this and that. The rules of proximity and distance I follow are laid out as rigidly as the lawns and paths in the park across the street. If, in the process of making a barricade, someone pulled down a tree, I don't think I would know how to refer to it. This tree, that tree, a tree, tree. If a fusillade rang out, I would still complete this sentence. If blood ran, I would still be here, sharing this room with that book about Sartre, that dispersing smoke, that supposed reader, this completed page.