John Greenwell lives in Canberra Australia. He was born on the 17th February 1932 in Sale, Victoria and was educated at Scotch College Melbourne. He studied law at Melbourne University where he won the Exhibitions in Property Law and the law of Torts. He was admitted to the Victorian Bar on the 1st April 1954 and practised as a barrister specialising in commercial and administrative law until August 1970. In March 1963 he became President of the Victorian Section of Amnesty International, the first Section of Amnesty established in Australia. In 1970 he joined the Australian Government and, in 1971, was in charge of the constitutional and legal areas in the government for Australia's external territories territories including Papua New Guinea, which was then in the process of acquiring self-government and moving to independence. In 1974 he became Director of the Papua New Guinea Office which was the body responsible for advising the Minister charged with bringing Papua New Guinea to Independence. In 1975 he joined the Commonwealth Attorney Generals Department and thereafter was in charge of the Business Affairs Division and at various times in charge of the intellectual property law, international trade and international business law (involving international negotiations on the problems of extraterritoriality) and subsequently for twelve months was in charge of Family Law. In 1987 he was appointed Deputy President of the Australian Law Reform Commission for five years during which he was a member of the Commission on various references, including Product Liability, and was in charge of an inquiry into the Customs Act. He retired in October 1992.

His work on Papua New Guinea led directly to the essay on Papua New Guinea Law and Independence on this site which discusses the legal system to be established in that newly emerging nation but significantly for the essays comprised in the Studies on Legalism it introduced him to a quite different kind of social order. It was, reflecting on this, that he formulated the three social orders – legalism, mediatory-custom and regulatory which featuure in those studies.

His experience in the early years of Amnesty International led to the essay written first in the 1970’s on the organization and the issues which it faced. It also led him to reflect on the genesis of the humanitarian idea and the humanitarian action in Europe which he came later to write about in the historical section of these essays.