Richard Henry Tawney was a man of deep Christian beliefs and powerful emotions, and nowhere can we gain as full a view of his mind and temperament, of the limitations of his ideas as well as their strengths, as in the Commonplace Book or diary which he kept at Manchester from 1912 to 1914. This document is a unique record of the assumptions which supported Tawney’s life long work as a socialist and as a scholar. The pattern of his historical interests and, in embryonic form, the outline of many of the arguments which he later developed in his three most influential books, The Acquisitive Society (1921), Religion and the Rise of Capitalism (1926), and Equality (1931), clearly emerge from the pages of this pre-war diary. He appears therein as a man engaged in the exploration of the internal world of his Christian beliefs; and also vigorously seeking to relate them to social and economic life. Though written sixty years ago, this private diary of a remarkable man of powerful moral convictions is no less pertinent today than it was then.