When we're at our best, politicians can put forward new ideas, test the arguments, hold power to account, and find shared ground where we can co-operate despite our differences.
When we're at our worst, we just bark at one another and let opportunities for progress pass us by.
Sadly the latter way of working is the default position. Over the last month we've seen both. One extraordinary week saw cross-party agreement, and an atmosphere of pride in what we can do when we work together.
A free vote to legalise same-sex marriage saw a huge majority for equality.
But it wasn't just the way MSPs voted which made an impact, it was also the tone of the debate and the respect shown between the politicians and the campaigners.
The very next day, after months of haggling over the budget, Labour and the SNP buried their differences and struck a deal to effectively neutralise the Bedroom Tax.
IT'S not always easy to reach compromise between political opponents, and these two parties are often tribally hostile to one another.
That week showed what was possible when goodwill breaks out.
More recently we've seen the opposite.
The Criminal Justice debate last week saw ugly scenes in the Chamber, as MSPs split over the abolition of the 'corroboration' rule that requires multiple sources of evidence in Scots courts.
Instead of Ministers proposing a clear alternative so that MSPs can judge whether it's an improvement and build a consensus on the right thing to do, the debate descended into a 'stairheid rammy'.
Of all the political issues we face, it's the independence debate where this hostility can be most damaging.
People still making their minds up won't have much chance if they just hear politicians shouting at one another.
Even less appealing is the influence of big business, with banks threatening to leave Scotland if we vote Yes, and airlines demanding even deeper tax breaks than they already enjoy.
We can't let the debate on Scotland's future be reduced to a choice between caving in to one bunch of multinationals or another.
A BETTER debate is possible, on both sides. The debate on independence deserves to be passionate, creative and inspiring.
But it will only achieve that if both sides are willing to listen, think, and set out a positive vision, instead of mindlessly shouting at one another.
Whatever the referendum result, we'll be in a stronger position to go forward if we've let our highest standards lead us, instead of our lowest.