MY father never forgot the night he answered a knock at the door during the Irish civil war.

A voice from the darkness muttered that his brother should go by the lough that night, not by the road. His brother was in the Free State Army. The voice was that of a cousin who had joined a flying column of the IRA. His brother went by the lough. The road was ambushed.

It is a tale before mobile phones - or any phones at all in that remote part of west Ireland. But the story of a family divided by politics is played out in too many countries in too many eras. It is happening here and it is happening now. And yet here there is no fear of bloodshed. We are witnessing the most civilised of constitutional upheavals - thus far.

But I watched with some sadness the BBC's Big Debate on Sunday evening. The studio audience was seated in separate banks: on one side No, on the other Yes. Throughout the discussion each responded in unison, with one side jeering or silent as the other cheered and vice versa.

But the BBC's demonstration of even handedness in its audience selection also presented starkly the clear fissure that has split our (until now) cohesive society. The usual mixture of individuals at pre-referendum political discussion programmes had become two opposing tribes.

Let's hope they never turn into two opposing mobs.

It was a glimpse of a division that could outlast the referendum. Whichever way the vote falls, wouldn't that be the saddest outcome of all?

During my upbringing - perhaps informed by their early experiences - I never knew how my parents voted. I could hazard a guess about my father but my mother's views remain unknown to me. As for asking how she cast her vote, it would have been as unthinkable as suggesting she read aloud the contents of her diary.

My parents' attitude was typical of their time. Then, as now, there were political activists who trumpeted their views but everyone else kept their voting intentions to themselves. It was a private matter.

What a contrast with today. Walk down any street and you will see windows of houses and flats plastered with stickers. People are wearing badges and bracelets. I've seen cars with Saltires flying from their windows. At the weekend I passed a huge Union flag planted in the middle of a field and a few miles further on a giant Yes on the top of a hill.

Personal convictions are broadcast on Twitter and Facebook, often with all the passion of the very recently converted. The famous, wealthy or influential declare their intentions to the media.

All this public identification with one side or the other makes us appear a binary society. It suggests that we are more polarised than we are.

For, in truth, aren't many of us on a journey?

Elaine C Smith said as much during Sunday's debate. Before the Millennium she was a vocal Labour supporter involved in bringing us devolution. Then she became a convert to the cause of independence. Her evolution must be shared by many - though not all shifted in the same direction.

If we cast an eye back on Scottish voting patterns it is clear how the country has changed its beliefs. Within living memory Scotland was a stronghold of Conservatism. Then it became a Labour heartland. Certainly there have been surges of support for the SNP but, until recent years, they have rolled in and rolled out again like a spring tide.

The Union has had clear majority support, until now.

And now, according to opinion polls, about half the country is supporting the call to ditch it in favour of independence. On both sides of the argument, supporters are putting their convictions in their front window or on their lapel or broadcasting it across the internet.

I know that announcing where you are, what you are doing and what you think about everything from Wonga to world events is the new normality. It is a mark of the freedom of thought and freedom of speech that we enjoy. People don't think twice about advertising their views. Sharing their voting intention has become part of their personal branding in this age of the individual.

But voting isn't about individuals. Voting is about majorities.

What matters for Scotland is how many of us think one way or the other - not which of us thinks which way. I would argue that it is better, healthier, to be focused on the trend, not individual opinion.

We have a private ballot for a reason. It is easy for people who live in cities in a free society to feel confident about saying what they think. It's harder for those who inhabit small communities or who live in sections of society where one view holds sway.

For people who are voting against the view of their employer or of their parents - or even of the bulk of their friends - privacy matters. Surely it is better for discretion to be normality than to be expected to declare your stance.

The Ballot Act of 1872 was an aid to true democracy. A secret ballot is a guard against intimidation and bribery. It's also a protection against silent pressures, like fear of being ostracised or knowing it might cost you a promotion.

Being expected to declare voting intention can cause people to be hypocritical or - worst of all - cast their vote against their true belief.

Besides, why do people label themselves by a snapshot in time? Even people with the deepest convictions find themselves mellowing and morphing. Could the never-never man, The Rev Ian Paisley, have dreamed that Martin McGuinness would mourn his death as a friend?

The vote on Thursday demands honesty and sincerity from us all. On its outcome rests all our futures. I have listened and weighed and measured. I will go to the polls to cast the fairest vote I can manage. But no, I won't tell you where I will put my cross. The referendum demands that I support Yes or No but I find virtue and failings on both sides of the argument.

Yes or No does not define me or my thinking. I'm certain most voters don't fit neatly into one or other camp. That's why this rush to labelling themselves is less than the true picture and is therefore reductive and false. It gives the impression of a divided society, one with little middle ground when, in fact, that's where most of us probably stand.

When this is behind us the losers will have a sense of grievance. Wouldn't it be better that they knew the zeitgeist was against them but didn't know for certain which of their friends and neighbours comprised it?

Many other countries would already be blood stained by now. How has Scotland remained so civilised? I think it is because the Yes-No voting divide doesn't exactly fit any other that exists, whether religious, class or political.

This is a new configuration of the population. It is a new divide - apparently close to 50-50. The quieter we are about our personal vote, the quicker we will be re-mingled. Whether the result is Yes or No, it can't be too soon for me.