It was to the ministry, as thus understood, that Cairns had devoted himself at the close of his University course and again just before he took license as a probationer, when for a short time, as we have seen, he had been drawn aside by the attractions of "sacred literature." He never thought of becoming a minister and was putting his main strength into philosophy and theology. Not that he now forswore all interest in either, but from the moment of his final decision, he had determined that the mid-current of his life should run in a different direction. Yet another important factor in the case is to be found in the circumstances of his Berwick ministry. Had his lot been cast in a quiet country place, with only a handful of people to look after, the great book might yet have been written. But he had to attend to a congregation whose membership was at first nearly six hundred, and afterwards rose to seven hundred and eighty and, with his standard of pastoral efficiency, this left him little leisure. Indeed it is wonderful that, under these conditions, he accomplished so much as he did--that he wrote his _North British_ articles, maintained a reputation which won for him so many offers of academic posts, and at the same time laid the foundation of a vast and spacious learning in Patristic and Reformation theology. Akin to his strictly ministerial work, and flowing out of it, was the work he did for his Church as a whole--the share he took in the Union negotiations with the Free Church during the ten years that these negotiations lasted, and the endless round of church openings and platform work to which his growing fame as a preacher and public speaker laid him open. But there is one other consideration which, although it is to some extent involved in what has already been said, deserves separate and very special attention. Although his friends and the public regretted his withdrawal from the speculative field, it is not so clear that he regretted it himself. He had, it is true, worked in it strenuously and with conspicuous success, and had revealed a natural aptitude for Christian apologetics of a very high order. But it does not appear that either his heart or his conscience were ever fully engaged in the work. He never seemed as if he were fighting for his life, because he always seemed to have another and an independent ground of certainty on which he based his real defence. There is a passage in his Life of Clark which bears upon this point so closely that it will be well to quote it here:--