When Dr. Cairns came to Edinburgh from Berwick, it was only to a limited extent that he allowed himself to take part in public work outside that which came to him as a minister and Professor of Theology. There were, however, two public questions which interested him deeply, and the solution of which he did what he could by speech and influence to further. One of these was the question of Temperance. During the first twenty years of his ministry he had not felt called upon to take up any strong position on this question, although personally he had always been one of the most abstemious of men. But about the year 1864 he had, without taking any pledge or enrolling himself on the books of any society, given up the use of alcohol. He had done so largely as an experiment--to see whether his influence would thereby be strengthened with those in his own congregation and beyond it whom he wished to reclaim from intemperance. When he became a professor he was invited to succeed Dr. Lindsay as President of the Students' Total Abstinence Society, and, as no absolute pledge was exacted from the members, he willingly agreed to do so. From this time his influence was more and more definitely enlisted on behalf of Total Abstinence, and in 1874 he took a further step. In trying to save from intemperance a friend in Berwick who was not a member of his own congregation, he urged him to join the Good Templars, at that time the only available society of total abstainers in the town. In order to strengthen his friend's hands, he agreed to join along with him. This step happily proved to be successful as regarded its original purpose, and Dr. Cairns remained a Good Templar during the rest of his life. While there were some things about the Order that did not appeal to him, such as the ritual, the "regalia," and the various grades of membership and of office, with their mysterious initials, he looked upon these things as non-essentials, and was in hearty sympathy with its general principles and work. But, although he was often urged to do so, he never would accept office nor advance beyond the initiatory stage of membership represented by the simple white "bib" of infancy. On coming to Edinburgh, he looked about for a Lodge to connect himself with, and ultimately chose one of the smallest and most obscure in the city. The members consisted chiefly of men and women who had to work so late that the hour of meeting could not be fixed earlier than 9 p.m. He was present at these meetings as often as he could, and only lamented that he could not attend more frequently.