He was responsible for establishing the modern education system in Bhutan, including its first high school (which is now its first accredited university, Sherubtse College).

[3] He received a Catholic primary education and successfully applied for scholarship at Loyola College, which included a high school.

[4] He was accepted into the Society of Jesus shortly after graduating from high school and joined the St. Stanislaus Novitiate in Guelph, Ontario on 14 August 1932.

[9] When Mackey arrived in Bhutan in October 1963, the Jesuits became the first Roman Catholic religious order allowed in the officially-Buddhist nation.

In 1985, he was granted honorary Bhutanese citizenship, and in 1988, when the Jesuits had to leave the country, their schools being taken over by the Government of Bhutan, he was allowed to remain.