What is an "Arbitrary Polarity?"

It's a phrase I have been kicking around in my head for years.
At first, I just liked the sound of the phrase.
But I soon realized that the mental rambling that I had been engaging in that produced the phrase had been onto something at least somewhat significant.
There are polarities that guide our thinking in certain areas for better or for worse.
An important example is the political polarity of Left and Right. Even the terms "Left" and "Right" refer to a visual representation of a polarity.
People who prefer not to think too deeply feel comfortable in the "Middle."
They like to feel "Mainstream."
They are often accused of "straddling the fence."
Most people who claim to be Agnostic make that claim because it makes them feel that they are in the middle of the Atheist/Holy-Roller polarity.
This harkens all the way back to Aristotle's "moderation in all things" ethic, in which he did, indeed, make a thorough case for staying close to the middle of almost any polarity. (See Aristotle's "Nicomachean Ethics.")
Upon close analysis, agnostics really fall into the Atheist camp by definition. An agnostic is not a theist. By definition, an Atheist is one who is not a Theist. (See George Smith's book, "Atheism: The Case Against God.")
Even the Left/Right polarity has been shown to be somewhat arbitrary, as demonstrated by the folks who designed the World's Smallest Political Quiz. (See http://www.theadvocates.org/quiz.html)
Deep analysis in almost any field of thought will reveal polarities that can be shown to be at least somewhat arbitrary.
And many of those polarities are deeply ingrained in our culture - we think of them as the correct way of viewing things.
The phrase "thinking outside of the box" is, in most cases, really just a way of saying "thinking outside of the arbitrary polarities we have been trained to use since early childhood."
War is largely a result of Us-And-Them thinking. (See Pink Floyd's "Dark Side of the Moon"!)
Another arbitrary polarity.
It's either/or thinking.
And you can be sure that, in one way or another, it is holding you back from making important discoveries, decisions, or changes in your own life.