It's called the salami effect. You take a piece of salami and cut a thin slice. The salami still seems the same size. Then you take another thin slice. Then another. Before anyone has really noticed, the salami is gone.
We seem to have been playing a lot of salami politics in this country in recent months.
First there was the 'Border poll' on the possibility of a united Ireland, which was suggested by Sinn Féin in the immediate wake of the Brexit result.
At least it seemed prepared for all eventualities regarding Brexit, a feat which was beyond the Government, which was so paralysed in the wake of the shock result that the Taoiseach flapped wildly while talking about the mysterious 'contingency plans' he had up his sleeve.
Then came the announcement of the planned change in our voting rules.
Should the diaspora have the right to vote in presidential elections? Should Irish citizens living abroad be allowed to vote in general elections?
Then there was the talk, once dormant but now revived, of allowing people in the North to vote in presidential elections.
It's all part of the same, ever decreasing salami, the end goal being, of course, a united Ireland.
Talk of a united Ireland seems to have almost come from nowhere in recent times, as various political interest groups exploit the febrile atmosphere created by the Brexit result.
But within a few short months - if even that - the media, political and academic classes are now not only discussing the idea as a theory, but warning the rest of us 'down South' to play nice, as if this is already some foregone conclusion.
Having spent long decades watching people try to force a united Ireland with a bang, it now appears as if we are meant to sit idly by and watch it being introduced with a whimper.
What we are currently witnessing is a classic, hysterical overreaction from an establishment that has been caught on the hop by Sinn Féin's gains in the Assembly, the aforementioned 'B' word and even Scotland's renewed calls for independence from the UK.
To a conspiratorial eye, it almost looks as if the groundwork has already been done and now we're just being softened up.
There are, however, plenty of flies in this ointment and the irony is that our leaders haven't learned the lesson of the Brexit poll, and still refuse to listen to the people.
Apart from anything else, a recent BBC poll found that 53pc of Northern Catholics had no interest in a united Ireland.
Then there are the economic realities - a united Ireland would mean a poorer Republic and a poorer Northern Ireland. It would place an unworkable financial burden on any new government. It would revive the resting but not dead spectre of sectarian violence once more erupting onto the streets. It would be an administrative and logistical nightmare.
But even more than that, it flies in the face of one of the great unspoken truths down South - most of us just don't really care about Northern Ireland.
One of the great shibboleths of this nation is a misty-eyed longing for the four green fields to once more be as one. But that's about as accurate as people declaring on their census form that they are Catholics who speak Irish, when most of them don't go to Mass and struggle with a cúpla focal - a comforting delusion that has little bearing on reality.
The actual reality is that we are two different entities with at least three different types of people sharing the same space.
To put it bluntly, the North is a foreign country where they do things differently. It has a different cultural background, obviously. It has a different history. It has its own unique virtues and failures and it is a separate state to us, one which deserves to be recognised on its own rights, without us enveloping them like a green-tinged amoeba.
Certainly, for anyone who grew up in the 1980s, the North was a place best kept at as far a remove as possible.
Out of sight, out of mind was the general philosophy, broken only by the latest senseless atrocity that then dominated the headlines until something else more gruesome happened in one of the world's other grim trouble spots.
The assumption, for example, that working-class people in the South were more Republican than the middle class always ignored the fact that the people who cared about the North cared about it the loudest.
In other words, it was usually easier to just keep the head down and not publicly admit that, actually, you didn't really care one way or the other.
It was a policy of benign indifference that occasionally morphed into outright resentment, particularly when confronted by Northern nationalists who seemed utterly incapable of grasping the fact that, for most of us 'Free Staters', our aspirations for Northern Ireland extended only as far as hoping that they would stop killing each other, and no further than that.
That used to be heresy, but no more.
Now we have a generation which is lucky enough to never have known a time when car bombs were synonymous with two cities - Belfast and Beirut.
But that doesn't mean they want a united Ireland any more than those old enough to remember those dark days.
To express such benign indifference to the North is not to display contempt or enmity. Far from it.
It is merely a realisation that many of us feel no more kinship with Northerners than we do with Welsh or Scottish or English people. Or, indeed, Americans or Australians.
It is also a rejection of inherited debts.
I was once condemned by a nationalist colleague for my apathy when it came to the 'Northern question'. Was it fair, she asked, that because of an accident of birth, she was born on the 'wrong' side of the Border, while I was not?
It was a bizarre argument, but not an isolated one. The idea that we Free Staters should tremble with fraternal solidarity about these people made as much sense to me as someone in the Creggan worrying about the state of our health service. In other words, we are where we are and we deal with it as best we can.
Northern Ireland is a separate country, with a separate identity.
Different countries. Different people. Let's keep it that way.