In recent months, I have been lecturing across the United States.

America is generally only interested in foreign affairs as they may impact on the homeland; but during my visits the question has often been raised about the future of Scotland and why it might want to withdraw from the United Kingdom.

When Americans try to relate this to domestic politics, they think of Texas seeking to secede from the Union or Northern California voting to be an independent state. No-one regards these as other than fancies of the nostalgic or fearful. By associating Scotland with Enlightenment and entrepreneurship, my American hosts are puzzled by the idea that it might possibly want to separate itself from the United Kingdom.

It looks, as in the domestic cases, like parochial regression. It seems clear that the referendum vote will, in fact, be to stay in the Union, the only questions being the scale of the turnout and the size of the majority.

I suspect the latter will be sizeable, but the former may be low. Admittedly, "something may turn up" to boost the Yes campaign; but "maybes" have to be converted into actual votes and support for the Union is more robust, its ratio to actual voting more reliable.

Whatever one's attitudes to independence the present situation is troubling. First, the referendum is viewed as an election.

Given that we have been brought here through the SNP gaining and retaining power, and independence is generally seen as its raison d'etre, it suits many on either side to view the vote as a verdict on the party.

But whatever the outcome, the main business of politics will remain and, even if independence were decisively rejected, the SNP would remain a contender for government.

Secondly, the debate is generally couched in economic terms. This makes a constitutional, political and cultural issue into another iteration of the "who manages best?" argument. Economics is important but it is not a question of nation or statehood. Moreover, we do not know how things will stand in 10 years time, let alone in a quarter of a century, but it is virtually certain that, whatever the conditions, they will not be significantly differentiated by state boundaries.

Thirdly, while Scotland prides itself on its sense of history and of intellectual, cultural and spiritual life, the tone of the debate is shrill and its substance shallow.

For all the talk of a "national conversation" engaging civil society and the people of Scotland, it is essentially narrowly political, between party politicians and committed political commentators.

There are mentions of Scottish intellectual and artistic traditions but these are generally rhetorical and ill-informed.

Smollett wrote in 1771 of Edinburgh as a '"hot bed of genius" but the genius was more widely distributed, centred on the universities and the philosophical clubs that span out of them, intersecting with the churches, the law and elements of the Scottish nobility.

Two aspects of this are worth noting. First, the Scottish renaissance began after the Act of Union and largely subsequent to the abandonment of the Jacobite cause among the educated. It also synthesised Scots and English cultural traditions and social forms, embracing the Union as a mutually enriching creation.

Hume and his contemporaries anglicised their prose and looked to London with a new sense of enlarged identity.

Secondly, the counterparts of these elements of Scottish society are largely absent from the present "debate" about Scotland's future.

In particular, those who might contribute out of learning and reflection remain notably silent. American public policy debates are extensively contributed to by academics and intellectuals and they assume that in Scotland but this is probably more widespread.

I hope that I might yet be able to say that this is so. But time is running short.