Using any reasonably objective criteria, devolution has been a success.

I think back to 1996 at Westminster, before devolution, when we had three bills that pertained directly to Scotland.

We've had over 360 pieces of legislation in Holyrood in the last 25 years. 

Some of that legislation has been groundbreaking.

Forgive me for being modest enough to raise the fact that we have free personal care.

We have free tuition fees. We've had the minimum unit pricing of alcohol, and the ban on smoking in public places.

Now these are all first-class pieces of legislation upon which there was real unity of purpose and a unity of outcome.

In addition, I also noticed recently that over 2,000 petitions have been received by the parliament.

This is a way of Scotland engaging in a more direct way than had been achieved previously.

The most important point about devolution was that it made the most significant dent in the massive centralisation of Westminster that we'd seen over the last 300 years.

So I take the long view and the long view will show Scotland becoming more impressive and making more progress.

However, when we look at the performance of the government and the parliament, I think there are some question marks.

I along with many other people wanted to see a new politics in Scotland. That simply hasn't happened.

The politics are toxic and it’s as tribal at Westminster, if not worse, at times.

I remember when you had political opponents, now you have political enemies.

And all the parties need to take some responsibility for that.

Maybe it was naive to think that a new institution, a new future, new ideas would give us a new politics.

What we've got is a reminder of what's happening elsewhere in Europe and in the US, where this whole question of grudge and grievance, resentment and revenge seems to surface on too many occasions.

Now, for a parliament with a big future and a nation with a big future, that's got to end.

One of the most divisive issues has been the whole question of independence.

Read more: Scottish Parliament 25 years on: opening day remembered

To be fair, the SNP has been electorally successful since 2007. You can't take that away from them.

What has happened is that I feel they've been too busy campaigning on independence and not effectively governing Scotland.

I like to think that politics should be in some respects be a unifying force but Scotland is more politically divided today than it has been in the last 25 years.

Now, I say that with regret because I have no idea what Scotland will be like in 15, 20, 25 years. I have no crystal ball, but this is certainly not a time for independence to be the most important issue in politics and especially for  the SNP.

There are huge public policy areas, including local government, including health, including education, and many more, where quite simply the focus on independence has meant that we've been distracted as a government, as a parliament, as a nation away from what is the most important issue, and that indeed, is building a devolved Scotland.

The Herald: First Minister of Scotland Alex Salmond and Prime Minister David Cameron sign a referendum agreement at St Andrew's House in Edinburgh on October 15, 2012 First Minister of Scotland Alex Salmond and Prime Minister David Cameron sign a referendum agreement at St Andrew's House in Edinburgh on October 15, 2012 (Image: PA)

Devolution needs to take another bold step forward. We need to write a new chapter in devolution.

We’ve got to be much more imaginative. We've got to make it exciting. We've got to spell out the meaning.

By nature, I’m an optimist. I'm passionate about Scotland. I'm passionate about the future of politics as well.

But I do think politicians have got to step back and think, ‘what is the purpose behind what we're doing?’

And it seems to me the overwhelming purpose is for the union of the United Kingdom is to be more competent and respectful than it currently is.

In 1603, we had the union of the crowns. In 1707 the union of the parliament. Is it not beyond the ken of politics to have now a union of nations? That's never been the case so far.

And that’s a challenge to Westminster, to see the whole of the United Kingdom through a different lens.

And it's also for the Scottish Parliament to actually move forward, build the nation and carry on the primary purpose which was to bring a legislature back to Scotland and enjoy the benefits.

Read more: Scotland should be proud of 25 years of devolution

If you look at devolution in phases, there was the first phase when Donald and I were involved. There was the second phase with Jack up to 2007. You've got the Alex Salmond years up to 2014.

In 2014, something critical happened. Clearly, the vote in the referendum was too close for some people. And then of course in 2015, the SNP won 56 out of the 59 Scottish seats, a quite unprecedented achievement.

For the last decade intergovernmental relations have deteriorated. Hostility and conflict have emerged.

That’s why I think the Scottish Parliament and the SNP have not served Scotland well and that's why we have some of the issues that John Swinney says he's going to tackle now.

What we've got to do in Scotland is to secure ourselves back to the original ideas of devolution, and look at how an ambitious nation like Scotland can perform more effectively.

And that means addressing some of the substantial policy issues that I think have been neglected.

That's not too much to ask. But the SNP if it's reaching out, will have to have a responsive set of other parties. I would ask them to cooperate and take Scotland forward.

This is a time for reflection. Regardless of what might be the political and constitutional future of Scotland, this is the time for Scotland to be the priority.

Henry McLeish is a former Labour MSP who served as First Minister from 2000 to 2001