ALL politics divides into Us and Them. The Berlin Wall and its big brother, the vastly longer armed border dividing East and West Germany, are visible topographical boundaries. On the low-ceiling flight from Frankfurt to Berlin, the death-strip dividing West from East is in full view - a scarlike swath which, until recently, no one dared cross without being shot, blown up by mines, or otherwise disposed of.
But the nature of these dividers is not essentially topographical. It is better caught by another nomenclature as the Iron Curtain - the armed German borders representing the ideological fault line between East and West, between European communism and capitalist democracy, the Soviet empire and the friends of the United States.
The division between Us and Them is not always so deadly. Historically speaking, however, it often is.
In the United States the issue of slavery came to represent two fundamentally different views of treating humans. The Gettysburg address - delivered on Nov. 19, 1863, its anniversary this Sunday - reminds us how geography can come to represent the combat of ideas.
``Now we are engaged in a great civil war,'' Abraham Lincoln said on that occasion, ``testing whether that nation, or any nation so conceived and so dedicated, can long endure. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live.'' He concluded with the appeal ``that this nation, under God, shall have a new birth of freedom - and that government of the people, by the people, and for the people, shall not perish from the earth.''
Political parties gather into coalitions the fragments of Us and Them. Issues like abortion come to be represented by loaded terminologies like pro-life and pro-choice. Divisions can run along ethnic and religious lines, as between the Boston's Brahmins and Irish. They can appear instinctual - the differences long subsumed in the history of the political warfare itself.
This subject of Us and Them is raised now by the need to understand what rationale exists for the political differences implicit in the Berlin and border walls. The Germans themselves are trying hard to understand, among themselves, who is Us and who is Them.
``I don't trust these people,'' Horst Eppard, an auto-industry manager from Frankfurt, was saying to me on the telephone this week, referring to the East German government leadership.
``Our people don't believe the East can make the reforms as quickly as they say,'' he added. ``The East's economy is so way down. That is their main problem. The people want a better life; but they will have to work for it. I don't know that they have the patience for that. They may have to suffer for the next five years.''
Last Sunday at noon the West German program ``Press Club'' was for the first time broadcast from East Berlin. ``The commentators cannot speak up as much as they want to,'' Eppard said after watching it. ``The East's politicians have said the only real existing socialism is in East Germany. Now they talk about a `human socialism.' Everybody knows socialism does not work. Central economic planning activities cannot work. Planning is an ideal to strive for. But how can it work without individual initiative?
``Here in West Germany the big problem is with living quarters. It's not just the people coming from East Germany. So many people asking West Germany for political asylum, people from all over the world. Only 3 percent are granted political asylum, but the rest are not sent back. From Turkey. Sri Lanka. They have to sit here and stay five years until they find out whether they are granted asylum. This costs a lot of money. Every month this year, 10,000 people asked for political asylum in West Germany.''
``Helmut Kohl is doing okay,'' my friend responds when I ask about how the West German political leadership is handling the situation. ``But not everybody likes him. It's not `in' to be a conservative these days.''