ANGLICAN social theology, the thinking behind the Church of England's commitment to reforming society as a whole, is sometimes labelled as "the Temple tradition" (as it is in the recently published Anglican Social Theology, edited by Malcolm Brown). On the 70th anniversary of his death (Sunday 26 October), it is worth examining who Temple was, and why he was so important in this area.

William Temple was the son of a Victorian Archbishop of Canterbury, Frederick Temple. When William became Archbishop in 1942, it was the only time a son had followed his father in that office.

William received a privileged upbringing at Rugby School and Oxford, and started his career as a lecturer in philosophy at that university. But during these years he was drawn into a different world through the Workers' Educational Association (WEA), which brought together university teachers and workers in co-operative education.

He later said that this work, and especially his contact with the founder of the WEA, Albert Mansbridge, was one of the most formative experiences of his life. "As a personal matter . . . he invented me." He maintained his involvement with the WEA for many years, serving as its president from 1908 to 1924.

Temple was ordained, and, after a spell as a not very successful headmaster of Repton School, became Rector of St James's, Piccadilly, then a Canon of Westminster, and then Bishop of Manchester in 1921, at the age of 40. He published extensively, was caught up in the Life and Liberty movement (campaigning for the C of E to be able to govern its own affairs away from Parliament), and began to develop his distinctive social theology.

Manchester diocese was then the most populous outside London. As he travelled through its industrial towns, Temple saw the acute social and economic hardships faced by the majority of the population. Those who worked in the mills faced harsh regimes, and those who were unemployed had no social security or health care; nor was there education beyond the age of 11, except for a few. Want, disease, squalor, ignorance, and idleness were scourges in the land.

Temple was not going to sit idly by. He convened the Conference on Politics, Economics and Citizenship (COPEC), which met in Birmingham in 1924 with 1400 delegates from different churches.

Its importance was that it weaned the Church's leadership away from high Tory attitudes to an acceptance of the Christian case for huge social reform and the development of a welfare state. Temple himself coined the term "welfare state" in lectures in 1928. He contrasted the "power state" of the pre-war Prussian nation, in which the state coerced its citizens for its own ends, with the "welfare state", in which the individual was primary, not society, and "the State exists for the citizen, not the citizen for the State."

IN 1929, Temple became Archbishop of York. He combined pastoral work with lecturing, campaigning, and writing his popular Readings in St John's Gospel. He sought to communicate a vision of the whole of life - religious, personal, economic, political - with Christ at the centre as the one who makes sense of the whole and illuminates it with his truth. He also became more and more involved with the ecumenical movement, helping to plan the World Council of Churches. Had he survived the war, it is extremely likely that he would have been its first president.

When war with Germany was declared in September 1939, Temple made a BBC radio broadcast to the nation in which he avoided the kind of jingoism preached at the start of the First World War. As became clear afterwards, he captured the mood of many in the country: one of "deep determination to fulfil a necessary but hateful duty". This broadcast turned Temple into a national leader. There was now little doubt that he would become the next Archbishop of Canterbury, and this duly happened in April 1942.

Temple and his wife moved into a bomb-damaged Lambeth Palace in London, and he fulfilled his duties while putting up with air raids by night and, later, flying bombs by day. His means of travel was on crowded buses and trains in the blackout.

THE social and economic needs of the population were very much in his mind, and he started asking what kind of society Britain should become once the war was over. In 1942, he published a slim Penguin Special, Christianity and Social Order, which quickly became a bestseller, selling 142,000 copies. With radical clarity, he set out the fundamental Christian principles that should govern the way a society organised its life, and drew out some of the practical implications of these principles.

He was guided in his policy recommendations by William Beveridge, the civil servant who put plans in place for the post-war welfare state, and the pre-eminent economist John Maynard Keynes, among others. The popularity and influence of the book has led to Temple's being described as one of the architects of the welfare state.

He also made some widely publicised remarks on the banking system, suggesting that the government should put curbs on profits, and restrictions on the issuing of credit by banks. The remarks were disliked by financiers, but again showed Temple challenging the current order in favour of a fairer post-war world.

Then, in 1944, he gave crucial backing to R. A. Butler's Education Act, which for the first time set up a national system that would include both state and church schools, and would raise the school leaving age to 15. Temple backed the Act because he saw this last measure as crucial for the population as a whole.

TEMPLE died of a heart attack on 26 October 1944. This was barely two-and-a-half years after becoming Archbishop of Canterbury. He was not to see Allied victory in the war, nor was he to assist with social and economic reconstruction afterwards.

But he had provided a vision of what a better society could look like, and, in his social theology, provided it with deep foundations. He won over many of the churchgoing middle classes, those who would subsequently pay for the welfare state through taxation. He is regarded by church historians as the most influential Archbishop of Canterbury of the 20th century; hence "the Temple tradition".

Dr Stephen Spencer is the author of William Temple: A calling to prophecy (2001) and the forthcoming Christ in All Things: William Temple and his writings (Canterbury Press, 2015). The William Temple Foundation is organising a conference in Manchester on Monday 10 November to examine the place of faiths in developing a just society (williamtemplefoundation.org.uk/conference2014/).