In the course of a long career my father sat in both the Court of Session, as a Senator of the College of Justice, and in the House of Lords, as a Lord of Appeal in Ordinary.

Had he been alive today, depending on his age and position, he might either have been one of the three Scottish judges who this week heard Joanna Cherry’s petition against the prorogation of parliament; or, since the Judicial Committee of the House of Lords has been replaced by the UK Supreme Court, a member of the Supreme Court panel which will hear the government’s appeal against the Scottish ruling next week.

My father was not a political man. He was more interested in the law in its purest application, and in the genealogy and country pursuits with which he spent his leisure time. He would instinctively have opposed Scottish independence, and probably also Brexit, although I don’t believe he had any very strong feelings about Europe. He voted Conservative in the same way that he went to church, out of habit and because it would have never occurred to him to do anything else.

On hearing the ‘senior Number 10 insider’ suggest yesterday that the Scottish judges’ ruling was of questionable impartiality, my father came to mind immediately. The idea that he might have made a politically motivated judgement in such a case is simply unthinkable. Although I knew none of his colleagues well, from the way he often spoke of them I’m certain the same would have been true of them, as I’m certain also that this remains the case throughout the Scottish judiciary.

The idea that he might have made a politically motivated judgement in such a case is simply unthinkable.

Being the eldest son of a judge could have its drawbacks, but one thing I recognised from an early age, and came to value more and more as I grew older, was the iron vein of integrity that ran through my father’s life. Like all those men and women who reach the bench, in Scotland and England, he earned his position through years of intense scrutiny of the facts and precedents and years of forensic argument in the lower courts. By the time he became a judge he knew the law inside out, his already considerable intellect now a finely whetted legal scalpel.

It would be no exaggeration to say that his reverence for the integrity of the law was similar to that of a surgeon’s for the sanctity of human life. The surgeon treats the patient who is brought before him or her regardless of belief or race or political persuasion. The judge interprets the law as she or he finds it, regardless of the pursuer’s (or defender’s) belief or race or political persuasion. This would most certainly have been his creed, as it would be that of the Lords Carloway, Brodie and Drummond Young.

In 2002 my father chaired the House of Lords Committee that investigated the crash of the RAF Chinook helicopter in the Mull of Kintyre in 1994 that killed all 29 on board. His conclusion, which the government of the day chose to ignore, was that the Ministry of Defence, in the person of two Air Marshalls, had acted ultra vires, beyond its authority, in blaming the pilots for the crash. Imagine if that judgement had been held up as some kind of politically motivated attack on the defenders of the realm. 

“When people begin to look into first principles … it becomes rather dangerous for the ruling classes.”

In fact, what I most remember was the hours he spent peering at the insides of a large model helicopter engine that sat on a table in his study. There could have been no better illustration of the fact that it was his grasp of the observable facts, and nothing else, that mattered to him at that moment.

“When people begin to look into first principles,” Don Roberto was quoted as saying in The Coatbridge Express in 1887, “ – the people who are called the mob and the swinish multitude, as the Tories call them – when they begin to look into first principles it becomes rather dangerous for the ruling classes.” He was speaking of the plight of the crofters and the need for land reform, but he could as well have been speaking of the activities of the current government. Looking into first principles is precisely what the Scottish judges were doing this week.

The initial response to their ruling from Number 10, and further afield, suggests that little has changed since 1932, when Don Roberto also wrote, in The Scots Independent, “Little by little Englishmen began to think that the two countries were really one, and not two ancient kingdoms that had entered into partnership.”

Whatever the outcome of the Supreme Court hearing next week (which my father, were he to be alive and on the panel, would approach with nothing more or less than an eagle eye for the matters of law it presented), the ruling this week from Edinburgh is a reminder of one aspect of the Union which is perhaps less palatable to some of its supporters: under its terms, the Scottish courts have parity with the English courts and must be listened to, like it or not.