Named after his maternal grandfather, Ramsay Macdonald, a distinguished English Presbyterian minister and scientist, Paton was born in London, the eldest son of a missionary statesman, William Paton. He became a Student Christian Movement (SCM) secretary (1936-1939) and established an ecumenical chaplaincy at the University of Birmingham. Ordained a deacon in the Church of England, he then went to China under the influence of his father's friend, R. O. Hall, first as a YMCA secretary, then as a Church Missionary Society missionary (1939-1945, 1947-1950).
The blindness and arrogance of the West, including Western churches and missions, regarding Chinese culture provoked from Paton his prophetic book, Christian Missions and the Judgment of God (1953; 2nd ed., with a biographical essay by his son, 1996). Like his first book, Blind Guides (1938), it makes for uncomfortable reading and he was an uncomfortable prophet. He also popularized the works of Reinhold Niebuhr and Dietrich Bonhoeffer in Britain and, equally significantly, devoted himself to researching Roland Allen and Robert Raikes and applying their message today.
Paton became editor of the SCM Press (1964-1969), but although a string of books bears testimony to his abi1ities, he was unhappy in that role. He was more of a politician than a diplomat, and the Church of England gave him no position higher than that of secretary of the Missionary and Ecumenical Council of the Church Assembly (1964-1969). He had previously been secretary of the Council for Ecumenical Cooperation (1959-1964). Archbishop Michael Ramsey made him a canon of Canterbury in 1966, and he was chaplain to Queen Elizabeth II (1972-1983). He served the World Council of Churches in a variety of capacities, not least through abiding friendships with Chinese church leaders. He was still a valued counselor, a mystic, and an interpreter for the Chinese churches in his last decade, when he was racked with pain and wasting illnesses. Alison, his wife and the daughter of John Stewart of Manchuria, was also an SCM secretary.