One vote or two for independence?
So just where are we now with this referendum business? In the previous Holyrood parliament, it proved impossible to find succour for one plebiscite. Now it is suggested we may require two.
A few basics. The constitution as an issue is reserved to Westminster in the Scotland Act 1998 along with such matters as defence, the macro-economy, time and space.
Therefore, reform of the constitution is, strictly, in Westminster's hands. That is why proposed changes to the Holyrood parliament's panoply of powers are in the Scotland Bill, presently being considered by Westminster.
However, politically, a nation's future lies in its own hands. Successive British prime ministers have conceded the principle - how could they not - that the people of Scotland cannot be held in the Union against their clearly expressed will.
So, strict constitutional theory and practice will not entirely do here. If the people of Scotland vote to leave the Union in a properly formed and properly held plebiscite then the process of ending that Union is ipso facto under way.
To be clear, though, Scottish Secretary Michael Moore is not in any way contesting the right of the Scottish people to determine their future.
Rather, he is suggesting that there might have to be two stages to the consultative process. One, to begin negotiations for ending the Union, should there be a Yes vote in Scotland. Two, upon the independence settlement which emerges from any such negotiations.
Firstly, a side issue. There have been one or two voices raised suggesting that any referendum should be held across the whole of the UK on the grounds that the whole of the UK would be potentially affected.
That has a patina of plausibility until one thinks further. It would be tantamount to saying that any referendum on whether Britain continues to be a member of the European Union should be conducted across the whole of the EU.
Just as Britain is a signatory member of the treaty comprising the EU, so Scotland is a signatory member of the treaty founding the UK. It is Scotland's call as to whether to depart from that treaty. Ditto England.
But how is that call to be expressed? Michael Moore is right to point out that the settlement which emerged from any negotiations between Edinburgh and London might diverge from the original expectations in Scotland. That might well argue the need for a final popular consultation.
However, it is surely over-stating the case to argue that it is only post-negotiation that such issues as the control of oil and the organisation of defence would or could be determined.
Surely, such matters would have been substantially aired during the progress of the initial referendum debate?
Equally, it is a little specious to rely upon the fact that the constitution is reserved in order to build a case for a final UK-led referendum.
Yes, the constitution is reserved. But, should the people of Scotland vote Yes in a referendum on independence, then they would be displaying their popular displeasure at such a reservation. They would be intrinsically challenging such a reservation.
So the constitution is presently reserved. Absolutely true. But, if the people of Scotland vote clearly and demonstrably in favour of independence, then the climate will have been changed by that very fact itself.
It will not be sensible or prudent at that stage to rely on a pre-referendum state of affairs which presupposes the supremacy of Westminster. That supremacy will have been contested in a popular vote.
Further, let us look at precedent. Would or could a referendum be binding? The recent AV referendum was binding in that, had the people voted yes, that would have been that: there was no provision for returning to the Houses of Parliament for a verdict.
The 1975 European referendum across the UK was consultative. It was designed to inform the UK government of the day as to the approach they should take.
The devolution referendums present a varied picture. The 1979 Scottish poll was binding provided the vote carried with more than 40% of the electorate voting yes. They did not and so the measure fell, despite protests.
The 1997 version was pre-legislative and, in effect, consultative. It was designed to begin the path to devolution, not to conclude it. The measure carried on both counts (establishing a parliament, giving it tax powers) and so the process began.
That 1997 referendum is, in effect, Alex Salmond's template. He suggests such an approach might be replicated by consulting people in Scotland as to whether they wish to begin the process of independence.
Further, that 1997 plebiscite is instructive. Ahead of polling, there was talk of the devolution bill facing a huge struggle to get through the Commons and Lords. In practice, such opposition subsided entirely in the face of the referendum verdict.
In other words, the political climate is altered by voting - as it should be.
However, it might reasonably be argued that the parallel cannot be taken too far. The 1997 referendum began the process of establishing a devolved parliament, not a sovereign state; a devolved structure which can and is being altered, which remains subject to Westminster influence and ultimate control.
It might be argued - it is being argued - that ending the Union is a much bigger step and thus would require a binding popular verdict upon the final outcome, not simply pre-negotiation consent.
However, such a referendum is not absolutely required. It could be argued that legitimacy had been granted by the earlier plebiscite.
These are not fixed matters. Politics is fluid. It is influenced by prevailing trends: one of which would be a Yes vote in a Scottish consultative ballot. If, of course, there were to be a No vote, the issue of a UK-led referendum would not arise.
Final thought. To be entirely fair to Mr Moore, he is not prescribing a fixed solution. He is pondering prospects and stating his likely preference.
Which, in itself, is indicative of one thing: those defending the Union have yet to determine a clear, coherent strategy for dealing with a majority SNP government. Or even who among them, individually or collectively, is best placed to make that call.