Papers of Alderman R. J. Ellis relating to Aberystwyth Borough Council and Cardiganshire County Council, mainly concerning planning and water, 1937-1975; letters relating to administration of estates, 1902-1976; personal papers, certificates, and diaries of R. J. Ellis, 1910-1972; and a letter from Irish politician Tim Healy, 1886.

Papers of Prof. Richard Aaron, 1904-1981, comprising drafts of Knowing and the Function of Reason (Oxford, 1971), and of 'Comte, Mill and Durkheim: the epistemological issues', [?1970s]; reviews of Aaron's published works and related material, 1936-1972; draft lectures, articles and teaching notes, 1956-1977; personal and family papers, 1904-1977; personal and academic correspondence, 1932-1976; correspondence relating to the resignation of Goronwy Rees as Principal of UCW, Aberystwyth, 1956; minutes, correspondence and papers relating to the Central Advisory Council for Education (Wales), 1946-1951, the Council for Wales and Monmouthshire, 1958-1963, and the BBC General Advisory Council, 1963-1971; discussion papers for meetings of the British Academy, 1980-1981; and papers relating to Welsh-medium higher education, 1955-1975. With the exception of Knowing and the Function of Reason, there appear to be no papers relating to his books.