Neil MacCormick, who died on Sunday aged 67, was appointed Regius Professor of Public Law at Edinburgh University at the early age of 31 and held the post for a record, and highly distinguished, 36 years.

GEORGE REID

Neil MacCormick, who died on Sunday aged 67, was appointed Regius Professor of Public Law at Edinburgh University at the early age of 31 and held the post for a record, and highly distinguished, 36 years. During his tenure, he developed theories on sovereignty and liberal nationalism which he advanced as an MEP and as author of the SNP's constitution for Scotland - theories which are today taught in law schools around the world.

MacCormick was born into an intensely home rule family in Park Quadrant, Glasgow, in 1941, and was in the gallery of the St Andrew's Halls when his father, "King" John MacCormick, launched the cross-party National Covenant and out on the streets thereafter helping to collect signatures for a Scottish Assembly. The failure of the initiative left him convinced that "goodwill was not enough" and that Scotland would change only when the SNP "won seats".

The other formative influence on MacCormick, his elder brother Iain (an SNP MP in the 1970s) and sisters Marion and Elspeth, was his mother, Margaret Miller. A Gorbals social worker, she provided clothes, day nurseries and "fresh air fortnights" in the countryside for women from deprived areas of the city. She left her children with a commitment to an inclusive society and MacCormick, in particular, with an inability to see ill in anybody.

MacCormick was always conscious of his family's Highland roots. At Glasgow High School, he became a dedicated piper - tutored at home "the Mull way" by his great uncles Neil and Dugald, who sang the melody as he did the fingering. It was a skill much in demand in later years at many events throughout Scotland and Europe, at which he would appear in bunnet and kilt, radiating bonhomie. In 1994, the family of John Smith invited him to play Laoidh Chaluim Chille (St Columba's Hymn) at the private interment of the Labour leader in Iona.

MacCormick studied philosophy and English at Glasgow University, honing his formidable debating skills at the union and forming lifelong friendships with Smith, Donald Dewar and Ming Campbell. A Snell Exhibition then took him to Balliol College for a BA in jurisprudence. During his time at Oxford, where he was president of the union, he decided to abandon his plans to go to the Bar and to concentrate on a career in legal philosophy.

In 1965, he was appointed as a lecturer at Queen's College, Dundee, followed by a return to Balliol as a fellow and tutor in jurisprudence. With his move to Edinburgh University four years later, and his subsequent publication of more than a dozen books and hundreds of academic papers, he established an international reputation as one of the leading legal philosophers of his age.

In 1982, Edinburgh awarded him the research degree of LLD; in 1992, he was appointed QC, honoris causa; in 2001, he was knighted in the birthday honours; and, in 2004, he received the Gold Medal of the Royal Society of Edinburgh.

Along the way, he served as Edinburgh's Dean of the Faculty of Law, vice-principal for international affairs, as a visiting professor in Europe, north America and Australia, and as a fellow of the British Academy.

MacCormick's ideas on democracy, the post-sovereign role of political communities, legal argumentation and the institutional theory of law expounded in his major works, Questioning Sovereignty (1999), Rhetoric and the Rule of Law (2005), and The Institutions of Law (2007) are today required reading in law schools around the world. It was a source of great satisfaction to him that in the past year he was able to complete the final volume of this series, Practical Reason in Law and Morality, which will be published next month. The book "largely wrote itself", he said, and took him back to his early roots and lifelong commitment to Scotland.

MacCormick joined the SNP in 1968 and immediately drew the odium of fundamentalists by writing, in The Scottish Debate, that it was "pretty obvious that devolution would have to precede independence". Thereafter, he worked, with other gradualists, to reposition the SNP as a Scandinavian-style social democratic party. His Constitution for Scotland provided the intellectual framework for the party's subsequent advances.

From 1979 onwards, he fought, unsuccessfully, six elections for the SNP. His efforts were rewarded in 1999 when he was elected as an MEP (and vice-president of the party). He immediately made his mark in the European Parliament through his erudition, natural charm and inclusive nationalism. His thoughtful contributions on the rights of natural communities to the Convention on the Future of Europe were widely praised, as was his dogged defence of Scottish fishing and ferries.

He was named Euro MP of the Year a record three times in The Herald Politician of the Year awards. "His very presence on the SNP benches," said one opponent, "brought credibility to the party."

Challenged on one occasion on British concerns about a takeover by Brussels, he commented: "The English think of sovereignty like property. If it is given away, it must belong to somebody else. The Scots think of sovereignty like virginity. It can be given away without belonging to anybody." And then, with a shy smile: "What's more, in the right circumstances, it can be a rewarding experience."

In 1992, after the dissolution of his first marriage, he married Flora Milne, whose family origins, like his, were in Mull. They made a well-matched couple, generous hosts and the jolliest of raconteurs, sharing their homes in Edinburgh and Brussels regularly with friends of all political persuasions and none.

With the election of an SNP government in 2007, MacCormick was appointed a special adviser on European Affairs to the First Minister. He then retired from Edinburgh University, intending to devote himself to Scottish governance, to some lecturing at New York University and to travel and "time together" with Flora.

It was not to be. Shortly afterwards he was diagnosed with inoperable cancer. He took the news with his usual good spirits and fortitude.

"You have to play the cards you get," he said.

And then, with a twinkle: "A bit of a Scottish position, you might say."

He is survived by his wife Flora; by three children from his first marriage to Karen Barr, Janet, Morag and Sheena; and by his three step-children, Ailsa, Roddie and Andy.