Forget the brain tumor—did you know that whenever you use a cellular telephone you're destroying your own existence? Convenience dissolves contingency, and as the facts of your current state fade to insignificance you are melting! melting! Who knew you were so soluble?

It started with the telegraph. For about ninety-eight percent of our history and all our existence before that, the top speed at which news could generally travel was that of a rider on a horse. Except for a little semaphore here and there until around 1840 nobody ever heard about any event until somebody else came to them and physically brought the word. This meant the event at point A could have no effect at point C until it had come through and affected point B. And, like any other effect of living matter, news was impeded or sped by geography, weather and season.

This bound the human world tightly to the physical world; there was a necessary mapping between the two, and human events could never happen without the mediation of their environment. This made society a solid; as in a crystal, where each atom has a fixed position, the degree of relationship between two places tended to be determined by their distance and placement.

The invention and development of instantaneous communication obliterated this bond. Now the news of an event can arrive at all points simultaneously, sparking a global reaction-flash. Society is now a gas, with no necessary relationship between different places and a tendency for any event to happen both in its place and everywhere else. The world hasn't grown smaller—it's become infinitely small; we inhabit a point.

Obviously the effect isn't absolute; we're still subject to limits and relationships in our need to move physical things around from place to place. Still, we've reduced these relationships too with machine transport, and as a rule the specific space that needs to be crossed matters less now than the characterless time necessary to cross it.

The telephone was an improvement on the telegraph and refined the effect, and getting telephones into houses amplified it. And then information instantaneity reached essential perfection with portable telephony—beyond this there's no place to go but straight into your head.

The ordinary telephone is a limited space eradicator. Whenever you use one you erupt violently and immediately into the dimensionless presence of your callee, but both of you do have to be at home, in your offices, or some other particular, specific place, and your two loci can't change or the connection breaks. Ordinary telephones are like mountain overlooks—they give an inordinately large range to your informational capabilities but they only work when you go to them. There are still limits—if you call someone when they aren't at home you can't talk to them; if you're expecting an important call you can't go out before it comes. There is still space and spatial discipline.

With cell phones you carry your overlook wherever you go; Zarathustra need never come down from his mountain. You're never not home and you're never not at your desk; you're in constant potential contact with everyone who knows you and many who don't. It's very convenient—none of the contingencies of your living can interfere with your universal access to everyone.

But while you're out of touch less this way, you're also less in touch. When calls are made on ordinary phones you both know at least where the other is, possibly what the environment is there, and something about what they're doing—most importantly they're talking to you. You're both someplace in particular, the telephone is a bridge between your respective, state-creating places, and the difference between your two states determines part of your relationship to each other.

But when you're using a cell phone your location and situation are irrelevant except as a matter of possible curiosity. It doesn't matter where either of you is since you haven't had to be there on purpose to make the call. You could be at home, but since it's irrelevant whether you are or not you get no state of at-homeness—you get a state of nowhere-in-particularness.

This is most true of the most common use of cell phones: talking while in transit. Modern transportation already makes travel more a matter of generic duration than of crossing real places; when you then link yourself to someone in an irrelevantly different place to kill that time, you eliminate the space and the time components of your state, leaving only the dimension of chat. As long as you don't lose that connection you don't care where you are or how long you're there, because the travelling that you're doing isn't what you're doing anyway—though the conversation is also not what you're doing since you need to watch the road. Now people have taken this dimensionless travel out of their cars and begun practicing it on foot, so everywhere you can see them walking around not being where they are, neither with the people they're talking to nor apart from them.

With cell phones the opportunity cost of talking to someone is effectively zero—that's what convenience is. But without opportunity costs there's no such thing as priority: since they can happen any time and any place, all conversations are reduced to the Incidental level of importance. No conversation can be so important that you'll need to change other plans in order to have it. At the same time, no plans will ever be important enough that you'll abandon a potential conversation—you were going to bring your phone anyway.

This is a big step towards a loss of importance for all activities. When you decide to marry someone it's very nice that you're choosing to spend the rest of your life with someone, but the real significance comes from the fact that you're choosing not to do that with everyone else that you might; you're saying "This one is worth more than all those together." That's why people object to adultery—your tawdry flings void the opportunity cost that makes the marriage valuable.

I was out with a friend recently, having a beer and discussing airline mergers, when his little phone rang. It was a coworker of his who had called to get his opinion about the guy she was right at that moment out on a date with. For about five minutes my friend discussed her situation with her. He was no longer with me, and the coworker was no longer with her date; I'd been evaporated and the date was being two-timed before there was even a relationship. For this to be possible means that my friend was never entirely with me to begin with, since this or a similar call could have come at any time, nor was the coworker entirely on her date. In another year or two it'll be possible for her to send a quick Instant Message to all her friends' phones at once, describing the dude and asking them to vote on him on the spot. So where, at that point, will she come into it anymore? The total communication system makes her—and every—presence ghostly and superfluous.

This isn't a problem of manners; people have always been rude or polite, and the ways they do so go in and out of style with the things they use. This is a matter of the discipline imposed by places and environmental contingencies. They provide a structure that we have (had) to determine ourselves against; not-us stuff that we need to account for and deal with if we're ever going to do anything. All our tools are for overcoming or ameliorating the limitations and conditions of Nature, enabling us to live in a human World, but it's only in relationship to those limitations and conditions that we're human—in isolation we're nothing but a collection of processes. Any process which is capable of amplifying its own action—like erosion, finance, or conformity—will inevitably do so until it runs against an external limitation that breaks the positive-feedback loop; in a collection of processes the ones that do this will quickly take over, dwarfing or destroying the ones that don't. So without the constraint of limitations not chosen by us, such as distance and unavailability, our activity (and our thought) is free to boil out into unbounded, positive-feedback tumescences.

That's not human. And that's the real reason you should hang up and drive.