A principal Universalist educator in the twentieth century, MacLean was born on Cape Breton Island, Nova Scotia to Neil and Peggy (MacRae) MacLean in 1892. Described later as a big rugged man with a Scottish accent, he had a Presbyterian background, and left high school before he graduated to go on a recruiting mission with the Presbyterian Missionary Society. He enrolled at Westminster Hall Seminary in Vancouver, British Columbia. For a time he was a horseback riding lay preacher, and he recounted this experience in The Galloping Gospel (1966). After that he went to McGill University. Before he could finish he entered military service in the medical corps for fours years during World War I. He attended the University of Edinburgh for one term, and then returned to McGill and finished his B.A. Then he attended the Theological College at McGill, where he was first exposed to modern Biblical criticism. He had difficulty getting licensed as a Presbyterian preacher because of his liberal views. He married Ruth Rogers in the spring of 1922, and they had two children. The Teachers College at Columbia University in New York granted him a fellowship, and he moved there, and was awarded a Ph.D. in 1930. Before he graduated he had been working as an instructor, and then the Canton Theological School of St. Lawrence University hired him in 1928. Eventually he became the Richardson Professor of Religious Education and Psychology. During his training he had become concerned about how the idea of God was taught to children because assumptions were made about what God looked like and whether or not God existed in the first place. After he went to St Lawrence, he published The New Era in Religious Education (1934).
MacLean remained an uncommitted liberal Christian until the 1940’s when he embraced Universalism, and then he was ordained in 1945 at the Church of the Divine Paternity in New York. In 1946 he was named chairman of the first Department of Education in the Universalist Church of America (UCA). He was appointed dean of the Theological School in 1951 to succeed John Murray Atwood. As dean he saw the immediate need to bolster the financial base, and a Development Office was established in 1957. He placed a strong emphasis on pastoral duties in preparing students for the ministry. MacLean retired from his position in 1960, as the two denominations were preparing to consolidate. As dean he also carried a heavy teaching load as well. Despite his best efforts, the school’s enrollment had not increased and financial problems still beset it. As a religious educator, MacLean placed prime value on the family as the base for religious growth. He spoke of modeling religious ideals by the whole community, so that in his educational model, “The Method Is the Message” (UUA Pamphlet, 1962), he said that education must be relevant to the child, the church, and the problems of the world. He did much to revolutionize religious education while he was at St. Lawrence, including adding courses in philosophy, psychology and youth work, as well as incorporating arts and crafts as a regular part of religious education curriculum. MacLean addressed many important religious questions in his The Wind in Both Ears (1965). After he left St. Lawrence, he served in retirement as minister of education at the First Unitarian Universalist Church in Cleveland. His ability to develop an educational structure that nurtures both children and adults was recognized in 1971 when the St. Lawrence Alumni Association established the Angus MacLean award for excellence in the field of religious education.