The Scottish Parliament prides itself on its ethics. The way it was built, the way it claims to behave, its aspirations for public health, its green credentials.

Engraved in the gold on the head of the parliament’s ceremonial mace are four words: wisdom, justice, compassion and integrity. These are the ideals that MSPs are expected to live up do.

How can it be right, then, for the MSP pension scheme to give £188,000 to a company whose technology aids lethal drone strikes – a company from which the University of Edinburgh withdrew its funds in 2013? How can MSPs justify backing a firm that makes the reactors that run Trident nuclear submarines to the tune of £244,000?

How do they feel about the £474,000 they lavish on big tobacco, which they banned people from using in public places because of the illnesses and deaths it causes? How about the £271,000 they put into a mining company blamed for social and environmental injustices in Colombia?

How can MSPs reconcile the £2.1 million they invest in fossil fuel firms with their noble pretensions to lead the world in combating climate pollution? Especially when no less than the governor of the Bank of England, Mark Carney, has warned of the high financial risks of continuing to fund fossil fuels?

It simply doesn’t make sense - rationally, financially or morally. The parliament is falling behind the growing international movement involving universities, churches, cities and governments to divest from companies engaged in unethical pursuits.

Some institutions have long avoided giving money to arms and tobacco companies. Last month campaigners said that 450 institutions in 43 countries managing more than £1.7 trillion had pledged to pull money out of fossil fuels.

In this context why has the Scottish Parliament shown so little interest in reforming its pension scheme? It seems it is easier to talk the talk, than walk the walk. It is no wonder that the small number of MSPs who have been fighting for change, like the Independent representative for the Highlands and Islands John Finnie, are becoming frustrated.

The excuses used to block change – it’s our ‘fiduciary duty’ or 'it’s not up to us' – are doubtful to say the least. It should be perfectly possible to reallocate the money to more ethical investments without impacting income.

And surely the parliament, the primary democratic body of our nation, can muster enough power to direct where its pension money is invested? In our view, it’s past time it began the process.