[A NOTE ON SOURCES]
THE most important source for this book is the collection of nearly five hundred boxes of personal papers amassed by Lord Beveridge and deposited in the British Library of Political Science. A collection of such size presented major problems of selection; and many topics covered at length in the primary sources are dealt with only superficially, or not at all. In so far as I pursued a guiding principle in selecting material, it was that Beveridge's chief interest for both the historian and general reader lay in his many and varied contributions to modern social policy. However, history has a habit of up-staging this kind of assumption; and I shall be the first to admit that an entirely different book might have been written by someone who sifted the sources in a different way.
In spite of the wealth of material available, the Beveridge collection proved to be incomplete. Beveridge's own rudimentary card-index to his papers referred to extensive correspondence with the other members of the Committee on Social Insurance and Allied Services, who helped to produce the famous Beveridge Report of 1942. On 9 April 1953 Beveridge wrote a long note to Lady Beveridge, advising her on manuscript sources for her book Beveridge and his Plan. In this note he referred to two boxes which contained his correspondence with the Social Insurance Committee, together with other correspondence relating to the Beveridge Report. These letters were not, however, used by Lady Beveridge in writing her book, nor were they found among the Beveridge papers when these were placed in the British Library of Political Science in the 1960s. The correspondence undoubtedly existed, because Beveridge himself listed the individual letters and made extracts from them (see his "Working Notes and Materials" in BP, IXa 37). A few of the missing letters were also referred to in his Autobiography, Power and Influence (pp. 305-8), although it was clearly his intention that the detailed account of the Beveridge Report should be included in his wife's book rather than his own. In spite of extensive inquiries I have been unable to discover what happened to these letters. The loss was not irreparable, as it was possible to make use of Beveridge's manuscript copies and to supplement them with a great deal of further material on the Social Insurance Committee available both among Beveridge's own papers and in the Public Record Office. However, it should be noted that the source material was defective in this important respect.