The Professor accorded a generous and helpful sympathy to those who were workers in the field in which he laboured himself with so great assiduity and success; and he was not only a member both of the Scottish History Society and of the Scottish Text Society, but took an active interest in their affairs. He was also one of the representatives of the Church of Scotland in the General Presbyterian Alliance from the date of its formation, and took part in the business of all its General Councils, at the first of which, held at Edinburgh in 1877, he laid on the table a paper which he had drawn up on "The Harmony between the Bibliology of the Westminster Confession and that of the earlier Reformed Confessions, exhibited in parallel columns." He was appointed Convener of the Committee on the Desiderata of the History of the Presbyterian Churches; and at the following General Council, held at Philadelphia in 1880, it fell to him, in consequence of the death of Principal Lorimer, who was Convener of the British section of the Committee on Creeds and Formulas of Subscription, to give in the report containing "Answers to Queries regarding Creeds and Confessions." The Answers as regards the Church of Scotland, which had been prepared by himself, are to be found in the Report of the Proceedings of the Council, pp. 969-984. When in America he also delivered a course of lectures at Alleghany. His connection with the Alliance brought him into close contact with some of the leading Presbyterian divines of Britain and America, with whom his opinions on the history of the doctrine, worship, and government of the Church carried great weight; and Dr Schaff has acknowledged his obligations to him, among others, in his well-known work entitled 'The Creeds of Christendom.'