Scorpion and Frog fable provides a warning about John Swinney's talk of healing division – Euan McColm

The scorpion’s having none of it. “Why would I do that? If I sting you, you’ll die and I’ll drown.” The frog is persuaded and invites the scorpion to scuttle onto his back. Halfway across, the scorpion stings the frog. “Oh, for f…” says the frog, “what did you do that for?” “I couldn’t help it,” replies the scorpion, “it’s in my nature.”

On his installation by colleagues on Monday as the new leader of the SNP, John Swinney did a lot of talking about change. If his party didn’t change the way it was going about things, then the future was bleak. Something else that had to change was the polarisation of Scotland’s politics.

Swinney does humility far better than Humza Yousaf, with whom you could always see the parts move, and so our new First Minister even conceded that he had “contributed” to the toxic nature of Scotland’s politics. Contributed is quite the understatement. Swinney is one of the architects of an SNP strategy that has demonised opponents, accusing critics of government failure of attacking Scotland, herself.

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Referendum result ignored

Scottish nationalists are often heard talking about how the 2014 referendum campaign was a most joyous celebration of democracy. But for every Scot who feels like that, one-and-a-bit of a Scot does not. For many of those who supported the Union, the referendum was a stressful process, made worse by the tone dictated by the SNP-led Yes movement.

When angry nationalists crowded, jostled and intimidated unionist politicians or screamed abuse in the real and virtual worlds, Swinney was silent. And the SNP’s post-referendum strategy – ignore the result, treat the majority’s preference with contempt, and continually demand a second vote which most people did not want – has only cemented division.

Swinney indicates his SNP government will reach out to unionists to pass laws and budgets

As Deputy First Minister under Nicola Sturgeon between 2014-23, Swinney had ample opportunity to try to bring together a nation divided by the constitutional clash. Instead, throughout that time, the Scottish Government preferred to fuel grievance than to reach out to – or even consider the wishes of – the majority.

Polarisation suited SNP

No political party can avoid some share of the blame for the miserable state of our national discourse but things reached what even Swinney recognises to be a new low under 17 years of the SNP in power. In order to succeed, nationalism requires division. It is fuelled by grievance, by the belief that one is being held back or done down by the “other”. Polarisation has suited the SNP for years.

In fact, rancorous division was nothing to be worried about until a couple of weeks ago when Humza Yousaf tore up the Bute House Agreement, ending the SNP’s power-sharing agreement with the Scottish Greens. The incoming First Minister now needs his opponents if he’s to pass legislation.

But when opposition parties hear John Swinney call for cooperation, they may wonder whether he’s more scorpion than peacemaker.