He retired from the UN in 1966 to resume his teaching career at McGill University. He remained active in the promotion of human rights in Canada and internationally until his death at the age of 90. He was a director of the International League for Human Rights; served as a member of the Royal Commission on the Status of Women; part of the team that launched Amnesty International Canada; and, with colleagues from McGill University, was instrumental in creating the Canadian Human Rights Foundation. He took part in a number of international commissions of inquiry, including a mission to the Philippines investigating human rights violations under Ferdinand Marcos. In Japan he represented Korean women forced to act as sex slaves. He also campaigned for reparations for Canadian prisoners of war under Japanese captivity.