These are grim times for liberal democracy. Ukrainians ousted their pro-Russian president after months of demonstrations in February, only to see their country dismembered by Moscow's first major military intervention in Eastern Europe since the Prague Spring in 1968. In July, Hungarian Prime Minister Viktor Orban, emulating Russia's Vladimir Putin and Turkey's Recep Tayyip Erdogan, cracked down on civil-society groups and publicly moved toward "illiberal" democracy in Hungary. And in Syria's civil war, more than 191,000 people have now died in what began three and a half years ago as a peaceful, pro-democracy movement—the equivalent of a fully loaded 747 passenger plane crashing without survivors every day for 15 months.

Over in Scotland, however, the democratic process is receiving a much-needed jolt. The question Scots will face on September 18 is short and sweet: "Should Scotland be an independent country?" 'Yes' supporters want to annul the 307-year Act of Union between England and Scotland; 'No' supporters want to keep the United Kingdom united (but perhaps with a little more power given to Scotland's regional legislature).

The Democracy Report

British and Scottish debates about the vote have been emotional and contentious. But the process itself is also remarkably fair, free, and open. Unlike the Irish Question that roiled 20th-century Britain, Scotland's independence bid has been accompanied by neither terrorism nor repression. Legions of "cybernats"—pugilistic 'Yes' supporters who've helped shaped the debate on social media—have even circumvented the British press to make their voices heard.

For Scottish nationalists, an independent Scotland and a more democratic Scotland are synonymous. The draft constitution put forth this summer by the ruling Scottish National Party (SNP) reflects this view:

Preparing a constitution is not merely a matter of placing words in a document—important though the words are—but of the Constitutional Convention process being Scotland's best opportunity to express our values, reflect our journey to this place, articulate our aspirations for future generations, engage our citizens, renew our institutions and methods of governance, and reinvigorate our democracy and civil society.

The draft constitution starts simply: "In Scotland, the people are sovereign." This may seem obvious to American observers, but it's revolutionary in the British political system. In Britain today, the people are not sovereign. All powers of state are instead vested in the British crown, currently worn by Queen Elizabeth II, and carried out by her ministers and by Parliament on her behalf.

By political convention, this is a legal fiction: Elizabeth plays no day-to-day role in governing Britain, and the House of Commons is freely elected by the British people. Were she to defy the prime minister and rule as the kings and queens of old, Parliament would simply abolish the monarchy. None of this is written down anywhere, but it is universally understood. The medley of medieval institutions, modern laws and political customs, and unspoken rules is known as Britain's "unwritten constitution."

An unwritten constitution isn't necessarily undemocratic. Even American politics, which revolves around the U.S. Constitution, operates by metatextual rules. Presumption of innocence isn't mentioned once in the U.S. Bill of Rights, for example, but the Supreme Court has held it to be "the undoubted law, axiomatic and elementary" in all criminal trials.

But America's constitutional system is still grounded in textual earth. The U.K. "constitution" is a series of reforms stacked upon reforms, like layers of sediment. These written laws and unwritten customs have, more often than not, transferred power from the Crown to Parliament—and only rarely from either institution to the people. The House of Lords may have lost its teeth, for example, but it is still unelected and astonishingly archaic. "Only in the UK and Iran do religious prelates automatically take a seat in the legislature," one observer noted, referring to Church of England bishops.

The U.S. constitution is heavily influenced by British democracy, but also by its perceived shortcomings. So is Scotland's draft document. Instead of welding the elected House of Commons to a House of Lords, Scotland's legislature would be unicameral and elected by proportional representation. Elizabeth II would reign as the first Queen of Scots in more than three centuries, but Scots would have a monarch as an expression of their sovereignty, not the other way around.

Scots law, long distinct from the Anglo-Norman legal tradition, would outpace it on human-rights protections, too. The Scottish constitution would explicitly forbid discrimination on the basis of age, disability, gender reassignment, marriage or civil partnership, pregnancy or maternity, race, religion or belief, sex, and/or sexual orientation. To safeguard these rights, the constitution would also enshrine total judicial independence. With few exceptions, U.K. courts cannot strike down laws passed by Parliament.

In some areas of governance, the Scottish constitution would also break new ground. Revenue from the North Sea oil fields would be crucial to Scotland's post-independence economy, but Section 32 of its draft constitution would also prioritize environmental protection:

(1) Every person is entitled to live in a healthy environment.

(2) Accordingly, and in recognition of the importance of the environment to the people of Scotland, the Scottish Government and public authorities must, in carrying out their functions, seek to protect and enhance the quality of the environment.

(3) In particular, they must seek to promote—

(a) the conservation of biodiversity,

(b) measures to tackle climate change.

The Scots would follow Ecuador, the Dominican Republic, and Tunisia in adding the fight against climate change to their nation's supreme law. Another section requires the "safe and expeditious" removal of all nuclear weapons from Scottish territory, imperiling Britain's nuclear deterrent.

The draft constitution suggests important differences in Scottish and British political philosophy. Since a Scottish devolution referendum narrowly failed in 1979—largely because of low voter turnout—the British welfare state has been gradually curtailed, first by Margaret Thatcher's Conservative governments and then by Tony Blair's "New Labour" governments. By contrast, 'Yes' supporters frequently cite Scandinavian social democracies like Norway, which leveraged its oil resources into a vast sovereign-wealth fund and robust welfare state, as models for independent Scotland to follow.

So what can Westminster promise to both save the Union and make it more democratic? One option would be full federalism. When a similar debate raged in 1912 over Ireland's constitutional status and the possibility of independence there, then-MP Winston Churchill proposed a dramatic reform scheme called "Home Rule All Around." Under his proposal, the U.K. would have created 10 regional parliaments to add another level of governance and representation. Three would go to Ireland, Scotland, and Wales to satisfy their desires for home rule. The remaining seven parliaments would go to regions of England, the largest and most populous part of the United Kingdom.

His logic was clear. "The United States has a great many Parliaments," Churchill told a crowd of his constituents in 1912. "Germany has separate kingdoms and principalities with armies woven into a strong federation; and Canada, South Africa, and Australia have found the federal system the only way to reconcile the general interests of the Commonwealth with the special development of each part of it." The United Kingdom is already a multinational country, he reasoned. Why not govern it like one?

Churchill's proposal received little support among British officials. Instead, Prime Minister David Lloyd George passed an Irish-only home-rule bill two years later, only to renege on it after the outbreak of World War I. An Irish uprising soon followed, along with civil war and terrorism. September 18, 2014—the date that SNP leader Alex Salmond scheduled for Scotland's independence referendum—will be the 100th anniversary of that failed Government of Ireland Act's passage into law.

Just as the Irish experience set a precedent for Scotland, so too will Scotland's decision set a precedent for the world. A week remains before the vote, but already the rumbling elsewhere in the U.K. and Europe has begun: Will Wales be next? What about Northern Ireland? Perhaps Cornwall will be the next Celtic region to seek more autonomy. Leaders of Scotland's outer islands, who feel as isolated from Edinburgh as from London, even raised the possibility last year of separating from both territories. Large and small separatist movements—in Flanders, Quebec, Corsica, Brittany, South Tyrol, Kurdistan, Veneto, Bavaria, Taiwan, Texas, and the Basque Country, to name just a few—are eagerly watching the Scottish debate and taking notes. Catalonia's government already plans to hold a similar referendum on independence from Spain on November 9, albeit without Madrid's blessing.

In an age where revolutions spread rapidly, nationalism can at times be pernicious and even dangerous. But the Scottish example sends a different message: separatism need not be incompatible with liberal and democratic values. Could that idea catch on, too?