It’ll be a game of two halves this party conference season.

Labour’s annual gathering in Brighton looks set to be anything but fraternal as the chasm between the party’s MPs and membership widens. By comparison the SNP conference in Aberdeen will be a seamless robe, a steady as she goes event with much mention of the SNP’s achievements in both parliaments and well-crafted speeches by party leaders, MPs and Holyrood candidates lambasting the Tories’ welfare and trade union “reforms.”, and next to none of the fractious debate set to dog Labour as delegates gather this weekend to consider the divisive issue of Trident.

Jeremy Corbyn wants to scrap plans to renew Britain’s nuclear deterrent but his shadow defence and foreign affairs secretaries oppose that position and some shadow ministers have privately suggested they might resign if there’s policy change. Those divisions have doubtless intensified since last weekend’s bizarre intervention by a military chief suggesting an armed coup might occur if a government opted to scrap Trident.

A Labour party aide has predicted: “There could be blood on the wall if this [debate] goes ahead. Just when we need to show some kind of discipline, it has the potential to show just how divided we are.”

Which makes you wonder why Labour’s conference committee put Trident on the agenda. Are they all Corbynistas – or just well-meaning party servants who know that truly big questions must be openly debated and democratically resolved?

A similar situation occurred in 2012 when the SNP leadership wanted to change the party’s anti-Nato stance and put its case to the annual conference in Perth. The result was one of the most dramatic, well-argued and passionate debates I have ever heard. The leadership position narrowly won the day but some members and two MSPs left the party. Yet despite visible dissent, support for the SNP continued to rise. Why? Perhaps it did the party good to show it had the courage to hold an important debate in public – and the articulate and committed members on both sides to do the subject justice... unlike the hesitant, covert, stage-managed Labour Party.

Now the boot appears to be on the other foot.

Next week Labour will have some heated, full-blooded debates for the first time in decades. That will prompt thousands to tune in and get engaged. By contrast the SNP conference in October will likely contain very little real dissent.

That’s partly because it doesn’t have the massive internal divisions that afflict Labour. The SNP doesn’t have to straddle the huge cultural and political divides that have reduced most UK parties to bit players north of the Border. The SNP doesn’t have to appeal to Middle England. It can unequivocally call for the House of Lords to be scrapped because it has no members. Nicola Sturgeon is so sure of loyal party support that she can even pledge to block Tory plans to scrap the Human Rights Act knowing her principled stand to protect the rights of other British citizens will only improve the SNP’s standing in next May’s Holyrood elections. With a higher positive rating than any other UK politician, there is no dissent anywhere about the SNP’s choice of leader.

But if politics is the language of priorities there will always be differences amongst SNP members and – more importantly – amongst the Scottish people. Scots have been encouraged to regard the SNP as Scotland’s Party and that carries the responsibility of being big enough to handle disagreement openly. And there are plenty of big issues – not just the timing of the next indyref or the possible rejection of the Scotland Bill if it falls short of Lord Smith’s proposals for devolution.

I spoke earlier this week at a meeting in Rothesay on Bute, where 90% of fields, hills, lochs, forests and foreshore are owned by a Trust set up by the Marquis of Bute – who spends most of his time in Switzerland. That same day proposals for two community wind turbines were rejected by Argyll and Bute’s planning committee. No councillor from Bute was involved. In Scotland, diktat by remote authority hardly provokes debate – yet archaic systems of land ownership and local democracy stifle initiative and prompt stagnation and despair as surely as domination by Westminster parties Scots don’t support.

All of this cries out for unrestrained, public debate. But that’s unlikely to happen at the SNP conference – though 70,000 new members may surprise.

Alex Salmond was doubtless correct when he said on Question Time that divided parties don’t win elections.

But where is genuine debate to take place? On websites run by volunteers? In newspapers with shoestring budgets?

If governments and political parties cannot handle the full range of debate for fear of looking unelectable, they must have the courage to back the agents of civic society who can.