Theologian and World Methodism's leading ecumenist. He served with the MMS in West Africa 1967-1973 and taught at The Queen's College, Birmingham 1973-79, before moving to America, first to Union Seminary, New York and then to Duke Divinity School, North Carolina. His Doxology (1980) pioneered the writing of systematic theology from a primarily liturgical perspective. He served on the Faith and Order Committee of the World Council of Churches from 1977 to 1991 and helped to guide the 'Baptism, Eucharist, Ministry' process that produced the 'Lima Report' of 1982. His involvement since 1986 in dialogues with Roman Catholics, Lutherans, Reformed and Anglicans is reflected in his Methodists in Dialog (1995) and he is currently engaged in Orthodox-Methodist dialogue.