A LOT of people get the wrong idea about an argument.

They can't see, or hear, past a single dull definition of the noun: the altercation, argy-bargy, the "heated exchange" over opposing views. That kind of argument is a fight with words. No finesse is required. At the moment, Scotland has no shortage of these verbal punch-ups.

The other meaning of the word ought to be more useful. It is certainly more testing for anyone interested in the truth rather than cheap propaganda. That version of argument is, broadly, a dispassionate attempt to persuade with facts, reason and logic. In this country, this year, there's a scarcity of the commodity.

You can tell as much from the number of people who have yet to decide how to vote in September's referendum. Depending on the poll, they might account for between one in seven and one in five of those who will choose Scotland's future. Time and again, these folk say they need more facts, more information, more clarity. What they really mean, I think, is that they want to hear arguments that are more than shouting matches. They want help in reaching that decision.

It probably says something about our society that we are still catching up with a Greek who died almost 2400 years ago. The dialogues created by Plato in the name of Socrates are sophisticated question-and-answer exercises designed to persuade audiences to think. In these works, point-scoring is for comic effect, often enough to demonstrate that point-scoring is pointless. Watch modern politics in action, on TV or social media, and you would think ancient wisdom was long lost.

Who still believes Holyrood's First Minister's Questions is a useful event? Why has John Bercow, Speaker of the Commons, just berated backbenchers for goonish behaviour at the equivalent Westminster event? What's the point now of the tag-match "debating" offered by the BBC's Question Time? Who, producers aside, watched STV's Scotland Tonight last week and failed to wince? More to the point, who was enlightened or persuaded?

STV, in fairness, made no attempt to disguise the nature of its presentation. Here was a "head to head" between Nicola Sturgeon, Deputy First Minister, and Johann Lamont, Scottish Labour's leader. Here they were "crossing swords in debate", with a pair of political editors looking on like boxing commentators. If someone said "Let battle commence", I missed it, but the general idea was plain. This was argument as combat.

Towards the end, each woman was invited to "cross-examine" the other. It made for a very slight change of pace in the hubbub of voices as two senior politicians sought to talk down and talk over any statement that didn't suit. Such is what passed for argument. It was irritating, even obnoxious, but it was also pointless. Sturgeon and Lamont might just as well have exchanged scripts in the first two minutes and gone home.

Had I been undecided as to the referendum, I might have been left wondering why I was wasting time. What we got, what we always get, was prepared rhetoric intended solely to defend a position. Might the undecided viewer have worked out that there is more to the Yes movement than a series of SNP policies? Was it clear that the No camp embraces people who despise Lamont's party? Was there the slightest attempt to raise the issue of self-determination above factional interest?

Throw that kind of rhetorical question at a politician and the pretence of bafflement will ensue. They are all staunch supporters of respectful, reasoned argument with a positive purpose. Not for them grubby point-scoring and verbal street-fighting. They care only for the facts and want - "passionately", as a rule - only to inform the electorate. Heckling people, talking over people, disparaging people with a third-rate one-liner from a paid hack? They deplore that kind of thing.

Amid all this Socratic virtue, the phenomenon of the undecided referendum voter remains to be explained. What does it mean to say "I don't know" when facts are available by the ton? There is now a flood of "information". It isn't hard to find. In fact, it's hard to escape. But help in making sense of statements is rare thanks to the desire - as Bernard Ponsonby, STV's political editor, put it last week - for "an old-fashioned rammie".

The politicians are trapped. Most of the time they are trapped by the instinct to say, like children in a playground fight, that the other lot started it. They are trapped by the desire for a good headline. They are trapped by voters and journalists who mistake a political debate for a TV talent contest. They are trapped by the unwritten rule that to agree with the other side even once is an admission of defeat. So debate becomes worthless.

A foreigner who doesn't know the territory would tell you ideological differences between the SNP and Scottish Labour are trivial, referendum or not. The imaginary foreigner would notice that profound historical, economic and cultural issues await resolution by an electorate entitled, in theory, to more than endless name-calling and negative campaigning. Then our observer would probably step back in astonishment, shaking their head at ritualistic nonsense.

The politicians are trapped, but also juvenile. In America, cajoling them into presidential TV debates worth the name requires weeks and months of negotiation. In Britain, the same juvenile haggling took place in 2010 and the result was Nick Clegg winning the talent contest. If Salmond ever gains his televised encounter with Cameron - the chances remain slim - all sorts of rules will have to be devised just to establish a difference between argument and argy-bargy. And it still won't work.

As real, living politics yields ground to virtual theatre, that useful definition of argument becomes history; the shouting match is the only debate in town. This probably doesn't matter if you have a TV programme to produce, but it leaves those undecided voters with a grievance. They need and want to make a choice, but find themselves shrouded in an electronic fog where people throw insults and slogans around.

That suits some. For my money, the No campaign have no interest in dealing with the larger issues. In my opinion, they poison the wells of discourse by indulging in party-political habits. But they would probably say - or shout - the same about me. Everyone claims to want that idealised argument, founded on the intrinsic merits of the case, without bluster or stunts, but no-one dares to risk such a thing.

It is now commonplace to say Scotland's future will be decided by those who are now undecided. Frustrating as such people can be, they have earned the right. Convince me, they say; show me how to decide as a mature, informed voter, but don't insult me with children's games. There is a while to go, I suspect, before that piece of Socratic wisdom sinks in.