THE Very Rev Professor James Whyte was Moderator of the General Assembly of the Church of Scotland in 1988-89 and was in the chair for the famous "Sermon on the Mound" by the then prime minister, Mrs Thatcher. Later in his term he preached to a worldwide TV congregation at the memorial service for victims of the Lockerbie Pan-Am bombing.

He was also one of those responsible for encouraging the controversial call of James Nelson, a murderer released on licence, to be a minister of the Kirk. In 1984, after several months of heated public controversy, Professor Whyte brought a petition to the General Assembly which opened the way to Mr Nelson's ordination.

He held the Chair of Practical Theology and Christian Ethics at St Andrews from 1958 to 1987. He had also been principal of St Mary's College there and played a leading, though at times severely critical, role in Scottish interchurch relations.

James Whyte, whose father was a Leith provision merchant, was born in 1920 and educated at Daniel Stewart's College, Edinburgh, where he was dux in 1937. He took a First in Philosophy at Edinburgh University before starting his Divinity course, drawn to the ministry through the influence of the Scottish Schoolboys Club.

He had been (in his own words) "pacifist with pink politics", but his opinions changed under the influence of events and the great American theologian, Reinhold Niebuhr. He was ordained in 1945 as an Army chaplain and saw service with the 1st Battalion Scots Guards in Trieste, then fiercely disputed between Italy and Yugoslavia. In 1949 he became minister of Dunollie Road Church, Oban, and moved in 1954 to Mayfield (then Mayfield North) in Edinburgh's south side.

But in 1958 came an "unplanned" call to what he henceforth regarded as his main ministry in St Andrews University, though a paucity of student candidates for the ministry limited the impact St Mary's College (the divinity school, where he was principal in 1978-82) made on the Kirk.

He came to regard his main achievement there as turning practical theology into an academic discipline, taught not only to divinity but to arts students. He also resisted suggestions that the Church and the universities were drifting apart, maintaining that there, as elsewhere in Scotland, there was more good will to the Kirk among non-members than was commonly realised.

His own theology was liberal, and he advocated an "open Church" as well as an ecumenical approach which "marginalised sectarianism".

But he could be tenaciously conservative in matters of liturgy and Presbyterian church order, as well as unfashionably realistic and plain-spoken in stating a Protestant view on interChurch ones.

On one occasion abroad he joined in a Roman Catholic Communion, "compelled by the Spirit". Yet he was also sharply critical of the Roman Church over the John Ogilvie canonisation and described a report of the Scottish interchurch Multilateral Conversation as having "almost every cliche in the ecumenical book, and none of them true."

Although he had himself been the Kirk's inter-church relations convener, he was a severe critic of the clericalism which he found in many ecumenical reports, and unconvinced by arguments of expediency that seemed to open the way to prelacy and even papalism.

He also founded his arguments in the Nelson case on a Protestant view of grace and justification by faith, successfully carrying the matter to the Assembly as a "dissenter and complainant" against his Presbytery's hesitation. James Nelson had been one of his St Andrews students and Whyte had no time for the argument that what might be lawful for the Church might not necessarily be expedient.

When elected Moderator in 1988 (after retiring from his chair and serving as associate minister at Hope Park Church in St Andrews), almost his first duty was to preside while Mrs Margaret Thatcher, who had been "noticed" in the gallery, addressed the Assembly. He handled a difficult situation with grace and aplomb, for a group of left-wingers objected to the invitation (which had precedents) and not merely the speech's economic theology.

He also formally presented the premierwith two Kirk committee reports more to his taste than hers.

Later in his term, in an Australian interview never publicised in Britain, he revealed how hostile he himself was to the "Sermon on the Mound".

In Scotland, however, he criticised the "theology by which we are governed", claiming that it did not recognise "a sense of community".

His moderatorial year continued to be taxing, through bereavement ? his wife died early in his term ? and uncertain health. He showed signs of strain during a moderatorial visit to England and collapsed at the opening of new Kirk TV facilities in Edinburgh. But he stood up well to the greatest strain of his year, when he preached at the memorial service in Lockerbie to the victims of the terrorist destruction of an American jumbo jet. He called for justice but not retaliation and sought to share "the comfort of God" with an audience far beyond the congregation of Dryfesdale Church. It was felt universally in the Kirk, and by people in many countries, that he had risen to the occasion and the least enviable of moderatorial tasks.

A minor decision of his term was to reach a compromise on moderatorial dress. His predecessor, Dr Duncan Shaw, had abandoned swallow-tail coat, breeches and lace in favour of a lounge suit. ProfessorWhyte reinstated part of the traditional garb for formal occasions, but with trousers and not the breeches, silk stockings, and buckled shoes.

In 1942 Professor Whyte had married Elisabeth Mill, daughter of a Kalimpong missionary. They had both been leaders of the Student Christian Movement in Edinburgh.

He accepted nomination as Moderator believing that she had sufficiently recovered from serious illness to help him through his term, but she died in 1988, a few weeks after his election. They had two sons and a daughter.

He is survived by his second wife.

Very Rev Professor James Whyte; born January 28, 1920, died June 17, 2005.