John Duns Scotus is a famous early Scottish philosopher (not to be confused with John Scotus Erigena), and his life and thought is explained by a Protestant and a Catholic writing in partnership.

James Torrance was Professor of Systematic Theology in the University of Aberdeen, and jointly convened the British Council of Churches Commission on the Doctrine of the Trinity. He was one of the conveners of the Joint Commission on Doctrine set up by the Church of Scotland and the Roman Catholic Church in Scotland. Earlier, he was a minister of Invergowrie Parish.

Roland Walls was the founder of the Fraternity of the Transfiguration at Roslin near Edinburgh. After serving for many years as an Episcopal priest and theological teacher, he was received into the Roman Catholic Church in later years.