It is the love that rarely speaks its name. For it is now unfashionable to talk of love of country, particularly as we prepare to mark the beginning of the first world war's four years of horror. But it is for love of the country of my birth that I shall vote no in the Scottish referendum on 18 September.

In pre-referendum Scotland it is necessary to state one's qualifications for publicly joining in the febrile and sometimes abusive debate about Scotland's future. One Scottish MSP has said that those who oppose independence are anti-Scottish, hence the need for me to establish credentials. I was born in Scotland, my parents were Scottish, I went to school and university in Scotland, I married a Scot, I qualified in and practised law in Scotland, I represent a Scottish constituency, and I am the chancellor of Scotland's oldest university.

I yield to no one in my love of my country. I shall vote no not because of uncertainties about membership of the EU or Nato, or the possibility of a currency union, but because I am unflinching in my belief that it is neither in the interests of the United Kingdom nor Scotland that we should separate. To do so would be to diminish both.

The advantages of the present union are often obscured by the smoke of the debate. For 300 years we have enjoyed the benefits of a single market. We have lived at peace with each other save for the last convulsions of Jacobitism in 1745. We have neither suffered invasion, nor civil war, fascism or communism. Look around you and see how few countries can make that claim. We have lived in a political system envied and copied around the world. We are members of the EU, Nato, the G7 and the Commonwealth, and have a permanent membership of the security council of the UN.

Nor have we lacked a Scottish political voice in the UK. We have been given a parliament and a referendum has been confirmed. In recent times David Steel, Robin Cook, Malcolm Rifkind, John Smith, Gordon Brown, Charles Kennedy, John Reid, Alistair Darling and others have occupied the great offices of state or led UK-wide political parties. And three Scots, James Mackay, Derry Irvine and Charlie Falconer have become, in turn, lord chancellors of Great Britain. Scotland and the Scottish have enjoyed influence beyond our size or reasonable expectation and in our UK, governments change seamlessly and without rancour. Our human rights are protected, we have a participative democracy, and the rule of law is our very foundation.

Movements for independence are often based on some form of discrimination – ethnic, religious or economic, a democratic deficit perhaps, or persecution or institutional prejudice. None of these has blighted Scotland's relationship with the rest of the UK. Has it been perfect? Of course not, but every few years we have had the unfettered choice to change course at successive elections. We invented the NHS, created the welfare state and, more peacefully than others, divested ourselves of our past to the extent that former colonies and dominions have morphed into a Commonwealth that even countries with no historic connection with the UK want to join.

In Scotland we have kept our own legal system, our church and even the right of our football team to play in the World Cup. Now we are invited to give up that history and the continuing opportunity it allows us. We are asked to make a decision that may be reversible in principle but in practice will be, to all intents and purposes, perpetual; to give up intangible benefits such as shared values, mutual respect, common responsibilities and family ties.

A decision in September to leave the UK will bind our successors for generations to come. Are we not entitled to clear and unequivocal evidence that to do so would do more than satisfy the ambition of one political party? Are we not entitled to be confident that we can meet the uncertainties of currency and of membership of international institutions? Do we not require evidence that an economy based on unpredictable oil reserves and revenues can be sustained, with promises of high public spending and low taxation? None of these assurances is available. Even on the balance of probabilities, the case for independence has not been made.

But those, like me, who exercise our right to argue against independence also have a duty. And that is to recognise that the majority of Scots still prefer a solution that allows Scotland to remain in the UK but for its parliament to have greater powers, most particularly economic. The Conservatives, Labour and Liberal Democrats publicly acknowledge this reality. They differ in nuance and detail, but not in principle.

The promises of the SNP are incapable of achievement, but it chooses to challenge the good faith of the three parties in their undertakings to embrace that principle. Its challenge would be effectively blunted if the three parties could agree on the process of implementation of that principle.

The secretary of state for Scotland should, in the event of a no vote, convene a meeting of representatives of these parties within 30 days of the vote. The parties should undertake to enter into heads of agreement, and put their proposals for greater powers for the Scottish parliament in their manifestos for the 2015 general election. And if in government, in whole or in part to introduce the appropriate legislation in the first Queen's speech after the election in May 2015. This would be the best and most practical demonstration of Better Together and "the best of both worlds".