The Fiction of Borders
It is a fact of life that borders only really exist if the protection of them is enforced. This does not necessarily mean oppression human interaction; the Atlantic and Pacific Oceans are both fabulously protective borders even without the Coast Guard. But is especially true borders between countries that offer easy passage back and forth are essentially meaningless except as symbolic divisions of geography. That is the principle theme which the novel is getting at it with invention of two separate cities occupying the same geographic space. Residents of the two cities in the story are required by law to interact only within their own city and to merely admit that the other city exists—to psychically rather than physically acknowledge the border separating one from the other is punishable crime known as breaching. Breaching becomes the metaphor by which the novel primarily explores its overarching them of the fictional status of borders in our reality.
The Nature of Perception
The nature of these two cities occupying one space is complicated especially as it relates to how one can be in two cities at once while interacting only within the confines of one and not the other. Basically this is accomplished through concentrated powers of perception. Residents of the respective cities must master the technique of “unseeing” which is a conscious effort to literally not see anything which is related to the other city. This can be quite a task as this can mean developing the ability to not consciously perceive what is literally right in front of you. The thematic point being made here is that people actually do this all the time and it is hardly specific or unique to the twin cities in the book. “Unseeing” is a commentary on the social condition of urban living in crowded cities in which people pass by even the most horrific sights by willy ignoring them and pretending they don’t see it or it isn’t there.
Crime and Punishment
The single most egregious crime that can be committed in either city is breaching. This constitutes not so much a violation of respecting the “border” separating the two cities as it is an existential violation of the entire notion of autonomous self-contained, self-governing bodies. Every community from the smallest one stoplight rural town to the most populous nations are constructed upon a collective agreement that they actually exist and have been given various amounts of authority over individual which comprise the population. If everybody in the most populous nation decided not to recognize this authority it would produce the same effect as if everybody in the smallest town had done so: society would as known would cease to exist because nobody would have any recognized authority over anybody else.
Essentially, this is the concept which makes borders so important because every autonomous society has them, whether they be a thousand mile stretch of desert or two square miles of city limits. Corruption runs rampant in both cities because no crime is recognized as more threatening to the stability of each city than maintaining the illusion of autonomy through the enforcement of belief in the fictional border separating them. And once more, of course, from this theme can be extrapolated a number of ways in which the same holds true in the world we live in.
