Mason was born in 1906, the son of a country doctor in the Derbyshire hills, who sent him to Sedbergh School and on to Balliol College, Oxford, where he took a first class degree in Philosophy, Politics and Economics. He joined the Indian Civil Service in 1928, and served successively as Assistant Magistrate in the United Provinces, Under-Secretary in the War Department, Deputy Commissioner in the Himalayan district of Garhwal - a remote, sub-Himalayan district of more than 5,000 square miles - Deputy Secretary in the Defence and War Department, Secretary to the Chiefs of Statf Committee and finally as Joint Secretary to the War Department, when his highly promising career was ended by Indian independence.
During the war years he had worked closely with Wavell and later with Mountbatten, and there could surely have been a continuing future for him in some other part of the Commonwealth or else in the rapidly expanding field of diplomacy, had he chosen to go that way. Instead, he decided for early retirement with his wife and four children to a smallholding in the west of England, where they hoped, with the help of his ready pen, to make ends meet.
It was a gamble and it did not work. The books came - seven novels and two volumes of The Men Who Ruled India (as The Founders and The Guardians were called when reprinted as one volume in 1985), about the major figures of the Indian Civil Service, all published under the pen name of Philip Woodruff between 1945 and 1954. But the financial return did not meet the needs of a family of six, and in 1952 he found part-time employment at the Royal Institute of International Affairs as Director of Studies in the newly established field of Race Relations.
It became his business both to undertake research himself and also to seek out, and guide towards publication, scholarly work in a variety of disciplines which had a bearing on racial problems. For his own first study he chose Southern Rhodesia, which was just then entering upon a highly controversial federation with Northern Rhodesia and Nyasaland.
In The Birth of a Dilemma (1958) he presented brilliantly the predicaments involved in the creation of a colony of settlement in a land already well occupied by indigenous populations. The successor volume called The Two Nations he left to a younger colleague, but himself contributed the third and most contemporary, The Year of Decision (1960).
Meanwhile, in London his post at Chatham House was burgeoning into the directorship of an independent Institute of Race Relations, for which he had not only to devise the programme but also to find the supporting funds. He still managed to have long weekends at home in the country for reading and writing, but his mid-weeks were busy with people.
A great believer in personal visits, he became a well-known figure in the offices of the international mining, banking and trading companies in the City of London and in those of the great charitable foundations. And he was to be seen early and late dispensing hospitality, though always with a serious purpose, to guests at the Athenaeum and Travellers' clubs.
The first large project of the new institute was the report Colour and Citizenship in 1969 by Jim Rose and Nicholas Deakin. It was prompted by the large migration from the Carib-bean and its sometimes ugly repercussions in British politics, and it did much to calm the atmosphere of public debate on British racial issues.
From here Mason's interests moved increasingly towards Latin America, where he set in motion several studies and travelled extensively himself with results that were apparent in Patterns of Dominance (1970), the last of his books to be written for the institute before he retired from the directorship in 1969.
He left behind him an apparently flourishing enterprise, with a magnificent record of sponsored publications and a promising team of six young research fellows to carry things forward. It was a sadness to him to watch his creation disintegrate as it fell victim to the academic disturbances of the next three years.
Nine more books were to follow during the first 15 years of Mason's retirement before blindness drew its curtain on his literary work. They included a short history of the Indian Army, A Matter of Honour (1974), a life of Kipling, The Glass, the Shadow and the Fire (1975), his Bampton lectures published as The Dove in Harness (1976), and two delightful volumes of autobiography, A Shaft of Sunlight (1978) and A Thread of Silk (1984).
The first concerns his Indian years and breathes the romance of empire (at least for those who ruled), with long days in the saddle and long evenings by the camp fire listening to the varied problems of his Indian clients. The second, necessarily less glamorous in content, centres on the world of ideas, institutions, and family.
Both are notable for the frank discussion of the part played in his life by his deep commitment to the Christian religion. For most of it he was an Anglo-Catholic, prepared for adult life by the Cowley Fathers, and with a faith much strengthened during a period of temporary blindness caused by a shooting accident in 1941, when his wife Mary read to him daily from the New Testament and they discussed its contents together.
During the institute years he wrote and lectured on Christianity and race. In 1975 he was invited to give the Bampton lectures at Oxford. But as Anglo-Catholics in an ordinary country parish, he and Mary increasingly felt themselves to be schismatics within an already schismatic church. At last in 1978, when he was 72, they decided to rejoin the mainstream as Roman Catholics.
The decision crystallised during a holiday in Venice, where they had sat together rapt in contemplation of Titian's altarpiece of the Assumption in the church of the Frari and he said to her, "I believe in that picture." Soon after their return home he said to her at breakfast, "Why don't we do it today?", and she replied, "Why not, indeed."
It was a characteristic decision, swiftly taken, even after half a century of searching, and it was adhered to with confidence to the end.
Philip Mason, colonial civil servant and writer: born London 19 March 1906; OBE 1942; CIE 1946; Director, Institute of Race Relations 1958-69; FRSL 1976; married 1935 Mary Hayes (two sons, two daughters); died Cambridge 25 January 1999.