PRETTY much every single sentence of British history ever written is potentially controversial or open to interpretation – especially the history of the British Empire. It is something the National Museum of Scotland now knows only too well.

In an exhibition in its Discoveries gallery, the museum describes the lives of the Scots who were involved in British colonialism. For many Scots, says the museum, the Empire was a chance to build a new career and a better life and to make some money. The exhibition also asserts that the Scottish empire-builders were motivated by personal ambition and what it describes as high principles. It is a view of the history of the Empire that has not gone down well at all.

One recent visitor to the museum, Nicola Perugini, has described his reaction to the display. Mr Perugini says he found the way it was presented, and the idea of empire building as a normal career motived by high principles, as extremely unsettling. “What would those who paid the price for colonialism and imperialism, and their descendants, some of whom live in our post-colonial societies, think of such a way of framing their history of dispossession?” asks Mr Perugini.

It is a reasonable question, although to be fair to the National Museum of Scotland, much of their description is a fair reflection of history. Scots were central to the Empire at all levels and for many of them it represented a chance for advancement and personal wealth. Famously, Robert Burns accepted the offer of a job managing a slave plantation and had dreams of making his fortune and returning to Scotland. For many Scots, the Empire was a job like any other.

However, the museum’s description of the work as principled is trickier, although it is perhaps the precise choice of words that is the problem. Many of the Scots who went out to work in the Empire saw themselves as doing good work, based on the idea of spreading the word of God, British values and “civilising” other nations. To that extent, their work was based on principles – just not principles that we would recognise or welcome now. Indeed, more than 100 years on, most of us would see the principles of the Empire as mis-placed religious certainty, arrogance or ignorance.

The National Museum of Scotland might also like to consider whether they have promoted the positives of the Empire without sufficiently acknowledging the negatives. There were certainly many positive consequences for the countries Britain ruled – bridges, roads, education, democracy – but the darker legacy is stark: the abuse of local populations, the proliferation of slavery, and perhaps even Britain’s continuing involvement in conflicts around the world. And, of course, Scots were right at the heart of it all. The hands that gripped the guns, swords and whips were very often Scottish.

The question is how we respond to this legacy. There is one school of thought that says we should expunge and edit the story by, for example, pulling down statutes to the controversial figures of Empire – the monument in Edinburgh for example to Henry Dundas, the Scottish lawyer and politician who helped delay the abolition of slavery. However, the argument put by Alex Salmond is more reasonable: leave the statues to the villains, but build bigger ones to the heroes.

As for museums that take on the subject of the British Empire, their responsibility is to ensure that their exhibitions and displays reflect the full complexity of the story. Naturally, we should acknowledge and explain the more troubling episodes in Scotland’s history but equally we should not be a prisoner of the certainties that some people assert – that the British Empire was all bad, for instance, or all good. The story is much more complicated than that and whenever it is told in public, we must do our best to make that clear.