According to Scottish nationalists, it's "Team Scotland vs Team Westminster." A Braveheart view of the past predisposes them to see separateness. Essential is retrieving the "lost world" of Scottish Britishness. Even before the union, it was growing inter-dependence that defined the relationship between the various parts of Britain.
In 1695, the Scottish government granted a license for the so-called Darien Company to plant a colony in Panama. To tap Spanish trade in the Caribbean, Scots had sunk some £153,000 - a quarter of the country's liquid capital - into a distant plantation. By 1700, tropical disease and Spanish raids had killed most of the colonists off. Edinburgh blamed London for not coming to its rescue.
A Union of Crowns had existed since 1603 when James VI of Scotland succeeded Elizabeth I to the throne of England as James I. But without a union of parliaments pooling risk and resources, London had no responsibility for Scottish commerce and no stake in a colonial enterprise that conflicted with England's need to keep Spain onboard against France.
Perhaps the biggest myth of all is that next week's referendum can return Scotland independence lost in 1707: the Darien scheme confronts us with two kingdoms legally separate but increasingly seen by their inhabitants as interdependent.
The referendum's thorniest issues - the pound, the economy, defense and a shared monarch - point us back to the problem 18th-century proponents of the union sought to fix: how to arrange the relationship of two nations, highly if unequally dependent on each other for trade and defense, that shared an island, a crown, a language and (we forget how important it was) the 1613 King James version of the Protestant Bible.
Unfashionable as it is to say, the union achieved what its designers meant it to - secure the diverse but inter-connected peoples of the island of Great Britain against foreign threats to their liberties, and promote their common prosperity.
For Scotland, the economic relationship with England, its Caribbean and North American colonies and the booming colonial trade in sugar and tobacco, was critical. For England, the imperative was strategic: fear of Louis XIV's France in Europe, on the high seas, in North America and India.
But an ideological conflict - the defense of Protestantism and parliamentary government (albeit with an excruciatingly limited franchise, especially in Scotland) - was crucial to the making of Britain. On both sides of the Tweed, Louis's France was the nightmare both feared most: absolutist and Catholic.
To fend it off, the two Protestant kingdoms of the island of Great Britain created a common market (then the world's largest), a common currency, common army and navy, with a common foreign policy directed through a common parliament at Westminster.
They pooled the national debt. By 1713, Louis was contained.
This Anglo-Scottish fiscal-military union out-strategized, out-spent and out-fought all its rivals. In the Seven Years' War (1756-63) and again in the Revolutionary and Napoleonic Wars (1793-1815), it defeated the French threat to Protestantism and parliament.
Victory at Trafalgar (1805) and Waterloo (1815) made possible the third element of Britain's high imperial credo: free trade - a Scots idea first expressed in Adam Smith's 1776 Wealth of Nations. Another Scots invention - James Watt's 1765 steam engine - made Britain's industrial lead unassailable for a century. By 1762, a Scot, Lord Bute, was prime minister.
The joint Anglo-Scottish Empire was to contemporaries as it is to us, British rather than English. By 1750, a quarter of the officers of the East India Company were Scots. A century later, William Mackinnon, from a middle-class Clyde family, founded a line of mail steamers (Mackinnon Mackenzie & Co.) that would become the British India Steam Navigation Company, official carrier of British troops as well as mail from the Persian Gulf to Burma.
The Scots presence all over the British Empire made Darien a distant memory. Its fruits reshaped Scottish cityscapes. Between 1745 and 1850, colonial wealth built Edinburgh's famous New Town. The Empire's second city until the 1950s, shipbuilding Glasgow, created a handsome center of its own. By 1880, as much as 40 percent of Australian borrowing was from middle-class savings in Scottish banks.
Union also promised an empire of Christ for Scots missionaries - unsurprising in a society so profoundly shaped by the Kirk. Born in 1813 in Lanarkshire and buried in 1873 in Westminster Abbey, David Livingstone took "Commerce and Christianity" to deepest Africa and became the patron saint of high Victorianism.
A British identity took longer to build than a British state. But by the mid-19th century, it had crystallized around what most Britons thought of as Britain's unique winning formula: Protestantism, parliamentary government and free trade. Among Scots, allegiance to this triune formula made the Conservative and Unionist Party the most successful political party north of the border until the 1960s.
Spurious is the argument of today's nationalists that Scotland got nothing more out of union than occupation. For generations of Scots, from Louis XIV until the defeat of Hitler, it meant the defense and expansion of British Protestantism, the protection of British freedoms symbolized in parliament and an arena for their talents, commercial and spiritual, as wide as could then be imagined: the free-trading British Empire.
Today, the empire is gone and Scots Protestantism is more cultural artifact than creed. But can nationalists' vision for Scotland outside the United Kingdom provide the security and prosperity previous generations identified in the union?
To trade a union that works for a separation that doesn't isn't a step forward; it's a step back to the unhappy days of 1700.
The SNP patriotically rejects the basing of Britain's nuclear force in Scotland but says an independent Scotland will shelter under NATO's nuclear umbrella - partly provided by Britain but dependent above all on Washington's goodwill.
The SNP trumpets "independence in Europe" and holds out Scots as more enthusiastic Europeans than the English. But why then the need for admission on Britain's terms - without the Euro and with London's passport controls? In the EU, too, bigger is better: in the depths of the euro crisis, Irish pleas for clemency fell on deaf ears in austerity-minded Berlin.
That crisis made clear that the European Union is manifestly not what the United Kingdom is: a fiscal-political union pooling risks at the same time as opportunities. British government bonds ("gilts") guarantee the pound; Eurobonds may never exist.
That's why the pound goes to the heart of the debate. Independence plus the Bank of England are probably the only terms on which the SNP can win. But why should the Bank of England (that is, British taxpayers south of the border) act as lender of last resort to Scottish banks or back Scottish government debt without control over how that debt is created?
To trade a union that works for a separation that doesn't isn't a step forward; it's a step back to the unhappy days of 1700. It's Darien without the Caribbean sun - the benefits of union without the risks. As Gordon Brown, Britain's most recent Scottish prime minister, has argued, a patriotism based on Scotland's real story of inter-dependence would look for allies south of the border for renegotiating the terms of the union rather than tearing it up (and inventing a separate past to justify it).
Lost in the fog-shrouded heather of nationalist romance is the truth that the peoples of Great Britain have always been as divided within their kingdoms as connected between. Scots nationalists remember the crushing of the clans at Culloden as English-imposed genocide. Eighteenth-century lowland Scots (Saxons, or "Sassenachs" to the Highlanders) saw in it deliverance from a Catholic tyranny with worrying links to France. None would have been caught dead in a kilt until Queen Victoria made it a fashion and the British Army made the Highlanders the loyal crack troops of Empire.
The "Yes" campaign shamelessly holds the union up as a failure. But if the modern parliamentary state was born in England's "Glorious Revolution" of 1689, it was the 1707 union with Scotland that secured it for posterity. And it was the successful Anglo-Scottish model of political and fiscal union rather than looser confederation that inspired the founding fathers in designing the United States and every successful union, including the Australian, since.
It's not fear that's clouding the referendum debate; it's amnesia about the scale of the union's achievements and the inter-dependence of the British peoples. After 1707, Scots and English (and Welsh) invented Britishness together. It's entirely within their creative capacity to reshape its content for the 21st century.