During 1877 and 1878 the United Presbyterian Church was much occupied with a discussion that had arisen in regard to its relation to the "Subordinate Standards," i.e. to the Westminster Confession of Faith and the Larger and Shorter Catechisms. These formed the official creed of the Church, and assent to them was exacted from all its ministers, probationers, and elders. A change of opinion, perhaps not so much regarding the doctrines set forth in these documents as regarding the perspective in which they were to be viewed, had been manifesting itself with the changing times. It was felt that standards of belief drawn up in view of the needs, reflecting the thought, and couched in the language of the seventeenth century, were not an adequate expression of the faith of the Church in the nineteenth century. The points with regard to which this difficulty was more acutely felt were chiefly in the region of the "Doctrines of Grace"—the Divine Decrees, the Freedom of the Human Will, and the Extent of the Atonement. Accordingly, a movement for greater liberty was set on foot.

There were many, of course, in the Church who had no sympathy with this movement, and who, if they had been properly organised and led, might have been able to defeat it. But the recognised and trusted leaders of the Church were of opinion that the matter must be sympathetically dealt with, and, on the motion of Principal Harper, the Synod of 1877 appointed a Committee to consider it, and to bring up a report. This Committee, of which Dr. Cairns was one of the conveners, soon found that, if relief were to be granted, they had only two alternatives before them. They must deal either with the Creed or with the terms of subscription to it. There were some who urged that an entirely new and much shorter Creed should be drawn up. Dr. Cairns was decidedly opposed to this proposal. The subject of the Creeds of the Reformed Churches was one of his many specialties in the field of Church History, and he had a reverence for those venerable documents, whose articles—so dry and formal to others—suggested to his imagination the centuries of momentous controversy which they summed up, and the great champions of the faith who had borne their part therein. Besides, he was very much alive to the danger of falling out of line with the other Presbyterian Churches in Great Britain and America, who still maintained, in some form or other, their allegiance to the Westminster Standards.

His influence prevailed, and the second alternative was adopted. A "Declaratory Statement" was drawn up of the sense in which, while retaining the Standards, the Church understood them. This Statement dealt with the points above referred to in a way that would, it was thought, give sufficient relief to consciences that had shrunk from the naked rigour of the words of the Confession, It also contained a paragraph which secured liberty of opinion on matters "not entering into the substance of the faith," the right of the Church to guard against abuse of this liberty being expressly reserved. Dr. Cairns submitted this "Declaratory Statement" to the Synods of 1878 and 1879, in speeches of notable power and wealth of historic illustration, and, in the latter year, it was unanimously adopted and became a "Declaratory Act." The precedent thus set has been followed by nearly all the Presbyterian Churches which have since then had occasion to deal with the same problem.

Except when he had to expound and recommend some scheme for which he had become responsible, or when he had been laid hold of by others to speak in behalf of a "Report" or a proposal in which they were interested, Dr. Cairns did not intervene often in the debates of the United Presbyterian Synod. He preferred, to the disappointment of many of his friends, to listen rather than to speak, and shrank from putting himself in any way forward. He had been Moderator of the Synod in 1872, and as an ex-Moderator he had the privilege, accorded by custom, of sitting on the platform of the Synod Hall on the benches to the right and left of the chair. But he never seemed comfortable up there. He would sit with his hands pressed together, and in a stooping posture, as if he wanted to make his big body as small and inconspicuous as possible; and, as often as he could, he would go down and take his place among the rank and file of the members far back in the hall. But he had all a true United Presbyterian's loyal affection for the Synod, and a peculiar delight in those reunions of old friends which its meetings afforded. Amongst his oldest friends was William Graham, who although, since the English Union, no longer a United Presbyterian, simply could not keep away from the haunts of his youth when the month of May came round. On such occasions he was always Dr. Cairns's guest at Spence Street. He kept things lively there with his nimble wit, and in particular subjected his host to a perpetual and merciless fire of "chaff." No one else ventured to assail him as Graham thus did; for, with all his geniality and unaffected humility, there was a certain personal dignity about him which few ventured to invade. But he took all his friend's banter with a smile of quiet enjoyment, and sometimes a more than usually outrageous sally would send him into convulsions of laughter, whose resounding peals filled the house with their echoes.

In the spring of 1879 died the venerable Principal Harper. Dr. Cairns felt the loss very keenly, for Dr. Harper had been a loyal and generous friend and colleague, on whose clear and firm judgment he had been wont to rely in many a difficult emergency. Besides, as his biographer has truly said, "he was habitually thankful to have someone near him whom he could fairly ask to take the foremost place."18 Now that Dr. Harper was gone, there seemed to be no doubt that that foremost place would be thrust upon him. These expectations were fulfilled by the Synod of that year, which unanimously and enthusiastically appointed him Principal of the College. His friend Dr. Graham, who, as a corresponding member from the Synod of the Presbyterian Church of England, supported the appointment, gave voice to the universal feeling when he described him as "a man of thought and labour and love and God, who had one defect which endeared him to them all—that he was the only man who did not know what a rare and noble man he was."

In the following year (1880) Principal Cairns delivered the Cunningham Lectures. These lectures were given on a Free Church foundation, instituted in memory of the distinguished theologian whose name it bears; and now for the first time the lecturer was chosen from beyond the borders of the Free Church. Dr. Cairns highly appreciated the compliment that was thus paid him, regarding it as a happy augury of the Union which he was sure was coming. He had chosen as his subject "Unbelief in the eighteenth century as contrasted with its earlier and later history"; and, although it was one in which he was already at home, he had again worked over the familiar ground with characteristic diligence and thoroughness. Thus, in preparing for one of the lectures, he read through twenty volumes of Voltaire, out of a set of fifty which had been put at his disposal by a friend. The first lecture dealt with Unbelief in the first four centuries, which he contrasted in several respects with that of the eighteenth. Then followed one on the Unbelief of the seventeenth century, then three on the Unbelief of the eighteenth century, in England, France, and Germany respectively; and, finally, one on the Unbelief of the nineteenth century, from whose representatives he selected three for special criticism as typical, viz. Strauss, Renan, and John Stuart Mill. These lectures, while not rising to the level of greatness, impress one with his mastery of the immense literature of the subject, and are characterised throughout by lucidity of arrangement and by sobriety and fairness of judgment. They were very well received when they were delivered, and were favourably reviewed when they were published a year later.19

Between the delivery and the publication of the Cunningham Lectures Dr. Cairns spent five months in the United States and Canada. The immediate object of this American tour was to fulfil an engagement to be present at the Philadelphia meeting of the General Council of the Presbyterian Alliance—an organisation in which he took the deepest interest, as it was in the line of his early aspirations after a great comprehensive Presbyterian Union. But he arranged his tour so as to enable him also to be present at the General Assembly of the American Presbyterian Church at Madison, and at that of the Presbyterian Church of Canada at Montreal. The rest of the time at his disposal he spent in lengthened excursions to various scenes of interest. He visited the historic localities of New England and crossed the continent to San Francisco, stopping on the way at Salt Lake City, and extending his journey to the Yo-Semite Valley. More than once he went far out of his way to seek out an old friend or the relative of some member of his Berwick congregation. Wherever he went he preached,—in fact every Sunday of these five months, including those he spent on the Atlantic, was thus occupied,—and everywhere his preaching and his personality made a deep impression. As regarded himself, he used to say that this American visit "lifted him out of many ruts" and gave him new views of the vitality of Christianity and new hopes for its future developments.

After the publication of the Cunningham Lectures there was a widely cherished hope that Dr. Cairns would produce something still more worthy of his powers and his reputation. He was now free from the incessant engagements of an active ministry, and he had by this time got his class lectures well in hand. But, although the opportunity had come, the interest in speculative questions had sensibly declined. There is an indication of this in the Cunningham Lectures themselves. In the last of these, as we have seen, he had selected Mill as the representative of English nineteenth-century Unbelief. Even then Mill was out of date; but Mill was the last British thinker whose system he had thoroughly mastered. In the index to his Life and Letters the names of Darwin and Herbert Spencer do not occur, and even in an Apologetic tract entitled Is the Evolution of Christianity from mere Natural Sources Credible? which he wrote in 1887 for the Religious Tract Society, there is no reference whatever to any writer of the Evolutionary School. With his attitude to later German theological literature it is somewhat different, for here he tried to keep himself abreast of the times. Yet even here the books that interested him most were mainly historical, such as the first volume of Ritschl's great work on Justification (almost the only German book he read in a translation), and the three volumes of Harnack's History of Dogma.

This decay of interest in speculative thought might be attributed to the decline of mental freshness and of hospitality to new ideas which often comes with advancing years, were it not that, in his case, there was no such decline. On the contrary, as his interest in speculative thought gradually withered, his interest on the side of scholarship and linguistics became greater than ever, and his energy here was always seeking new outlets for itself. When he was nearly sixty he began the study of Assyrian. He did so in connection with his lectures on Apologetics,—because he wanted to give his class some idea of the confirmation of the Scripture records, which he believed were to be found in the cuneiform inscriptions. But ere long the study took possession of him. His letters, and the little time-table diary of his daily studies, record the hours he devoted to it. When he went to America he took his Assyrian books with him, and pored over them on the voyage whenever the Atlantic would allow him to do so. And he was fully convinced that what interested him so intensely must interest his students too. One of them, the Rev. J.H. Leckie, thus describes how he sought to make them share in his enthusiasm:—

"One day when we came down to the class, we found the blackboard covered with an Assyrian inscription written out by himself before lecture hour, and the zest, the joy with which he discoursed upon the strange figures and signs showed that, though white of hair and bent in frame, he was in the real nature of him very young. For two days he lectured on this inscription with the most assured belief that we were following every word, and there was deep regret in his face and in his voice when he said, 'And now, gentlemen, I am afraid we must return to our theology.'"20

Another of his students, referring to the same lectures, writes as follows:—

"It was fine, and one loves him all the more for it, but it was exasperating too, with such tremendous issues at stake in the world of living thought, to see him pounding away at those truculent old Red Indians in their barbarian original tongue. Yet I would not for much forget those days when we saw him escaping utterly from all worries and troubles and perfectly happy before a blackboard covered with amazing characters. It was pure innocent delight in a new world of knowledge, like a child's in a new story-book."

When he was sixty-three he added Arabic to his other acquirements. It is not quite clear whether he had in view any purpose in connection with his professional work beyond the desire to know the originals of all the authorities quoted in his lectures. But, when he had sufficiently mastered the language to be able to read the Koran, he knew that he had two grounds for self-congratulation, and these were sufficiently characteristic. One was that he had his revenge on Gibbon, who had described so triumphantly the career of the Saracens and who yet had not known a word of their language. The other was that he was now able to pray in Arabic for the conversion of the Mohammedans.

About the same time he began to learn Dutch. He assigned as one reason for this that he wanted to read Kuenen's works. But as the only one of these that he had was in his library already, having come to him from the effects of a deceased friend, it is possible that this was just an unconscious excuse on his part for indulging in the luxury of learning a new language—that he read Kuenen in order to learn Dutch, instead of learning Dutch in order to read Kuenen. However, his knowledge of the language enabled him to follow closely a movement which excited his interest in no common degree, viz. the secession of a large evangelical party from the rationalistic State Church of Holland, under Abraham Kuyper, the present Prime Minister of that country, and their organisation into a Free Presbyterian Church.

Other languages at which he worked during this period were Spanish, of which he acquired the rudiments during his tour in California; and Dano-Norwegian, which he picked up during a month's residence at Christiania in 1877, and furbished for a meeting of the Evangelical Alliance at Copenhagen in 1884. All this time he was pursuing his Patristic and other historical studies with unflagging vigour, always writing new lectures, always maintaining his love of abstract knowledge and his eager desire to add to his already vast stores of learning. When, a year and a half before his death, a vacancy occurred in the Church History chair in the College, he stepped into the breach and delivered a course of lectures on the Fathers, which took his class by storm.

"His manner," says one who heard these lectures, "was quite different in the Church History classroom from what it was in that of Systematic Theology. In the latter he taught like a man who felt wearied and old; but in the former he showed a surprising freshness and enthusiasm. It was delightful to see him in the Church History class forgetting age and care, and away back in spirit with Origen and his other old friends."

These lectures, while abounding in searching and masterly criticism of doctrinal views, are specially noticeable for their delineation of the living power of Christianity as exhibited in the men and the times with which they deal. This was the aspect of Christian truth which had all along attracted him. It was what had determined his choice of the ministry as the main work of his life, and in his later years it still asserted its power over him. Although he had now no longer a ministerial charge of his own, he could not separate himself from the active work of the Church—he could not withdraw from contact with the Christian life which it manifested.

During the winter months he preached a good deal in Edinburgh, especially by way of helping young or weak congregations, more than one of which he had at different times under his immediate care until they had been lifted out of the worst of their difficulties. In summer he ranged over the whole United Presbyterian Church from Shetland to Galloway, preaching to great gatherings wherever he went. In arranging these expeditions, he always gave the preference to those applications which came to him from poor, outlying, and sparsely peopled districts, where discouragements were greatest and the struggle to "maintain ordinances" was most severe. His visits helped to lift the burden from many a weary back, and never failed to leave happy and inspiring memories behind them. Among these summer engagements he always kept a place for his old congregation at Berwick, which he regularly visited in the month of June, preaching twice in the church on Sunday, and finishing the day's work by preaching again from the steps of the Town Hall in the evening. On these occasions the broad High Street, at the foot of which the Town Hall stands, was always crowded from side to side and a long way up its course, while all the windows within earshot were thrown open and filled with eager listeners.

In this continual pursuit of knowledge, and in the contemplation, whether in history or in the world around him, of Christianity as a Life, his main interests more and more lay. In the one we can trace the influence of Hamilton, in the other perhaps that of Neander—the two teachers of his youth who had most deeply impressed him. Relatively to these, Systematic Theology, and even Apologetics, receded into the background. Secure in his "aliquid inconcussum," he came increasingly to regard the life of the individual Christian and the collective life of the Church as the most convincing of all witnesses to the Unseen and the Supernatural.

Meanwhile the apologetic of his own life was becoming ever more impressive. In the years 1886 and 1887 he lost by death several of his dearest friends. In the former year died Dr. W.B. Robertson of Irvine; and, later, Dr. John Ker, who had been his fellow-student at the University and at the Divinity Hall, his neighbour at Alnwick in the early Berwick days, and at last his colleague as a professor in the United Presbyterian College. In the early part of the following year his youngest sister, Agnes, who with her husband, the Rev. J.C. Meiklejohn, had come to live in Edinburgh two years before for the better treatment of what proved to be a mortal disease, passed away. And in the autumn he lost the last and the dearest of the friends that had been left to him in these later years, William Graham. These losses brought him yet closer than he had been before to the unseen and eternal world.

He was habitually reticent about his inner life and his habits of devotion. No one knew his times of prayer or how long they lasted. Once, indeed, his simplicity of character betrayed him in regard to this matter. The door of his retiring-room at the College was without a key, and he would not give so much trouble as to ask for one. So, in order that he might be quite undisturbed, he piled up some forms and chairs against the door on the inside, forgetting entirely that the upper part of it was obscure glass and that his barricade was perfectly visible from without. It need not be said that no one interrupted him or interfered with his belief that he had been unobserved by any human eye. But it did not require an accidental disclosure like this to reveal the fact that he spent much time in prayer. No one who knew him ever so little could doubt this, and no one could hear him praying in public without feeling sure that he had learned how to do it by long experience in the school of private devotion.

Purified thus by trial and nourished by prayer, his character went on developing and deepening. His humility, utterly unaffected, like everything else about him, became if possible more marked. He was not merely willing to take the lowest room, but far happiest when he was allowed to take it. In one of his classes there was a blind student, and, when a written examination came on, the question arose, How was he to take part in it? Principal Cairns offered to write down the answers to the examination questions to his student's dictation, and it was only after lengthened argument and extreme reluctance on his part that he was led to see that the authorities would not consent to this arrangement.

It was the same with his charity. He was always putting favourable constructions on people's motives and believing good things of them, even when other people could find very little ground for doing so. In all sincerity he would carry this sometimes to amusing lengths. Reference has been made to this already, but the following further illustration of it may be added here. One day, when in company with a friend, the conversation turned on a meeting at which Dr. Cairns had recently been present. At this meeting there was a large array of speakers, and a time limit had to be imposed to allow all of them to be heard. One of the speakers, however, when arrested by the chairman's bell, appealed to the audience, with whom he was getting on extremely well, for more time. Encouraged by their applause, he went on and finished his speech, with the result that some of his fellow-speakers who had come long distances to address the meeting were crushed into a corner, if not crowded out. Dr. Cairns somehow suspected that his friend was going to say something strong about this speaker's conduct, and, before a word could be spoken, rushed to his defence. "He couldn't help himself. He was at the mercy of that shouting audience—a most unmannerly mob!" And then, feeling that he had rather overshot the mark, he added in a parenthetic murmur, "Excellent Christian people they were, no doubt!"

But not the least noticeable thing about him remains to be mentioned—the persistent hopefulness of his outlook. This became always more pronounced as he grew older. Others, when they saw the advancing forces of evil, might tremble for the Ark of God; but he saw no occasion for trembling, and he declined to do so. He was sure that the great struggle that was going on was bound sooner or later, and rather sooner than later, to issue in victory for the cause he loved. And although his great knowledge of the past, and his enthusiasm for the great men who had lived in it, might have been expected to draw his eyes to it with regretful longing, he liked much better to look forward than to look back, using as he did so the words of a favourite motto; "The best is yet to be."

All these qualities found expression in a speech he delivered on the occasion of the presentation of his portrait to the United Presbyterian Synod in May 1888. This portrait had been subscribed for by the ministers and laymen of the Church, and painted by Mr. W.E. Lockhart, R.S.A. The presentation took place in a crowded house, and amid a scene of enthusiasm which no one who witnessed it can ever forget. Principal Cairns concluded a brief address thus: "I have now preached for forty-three years and have been a Professor of Theology for more than twenty, and I find every year how much grander the gospel of the grace of God becomes, and how much deeper, vaster, and more unsearchable the riches of Christ, which it is the function of theology to explore. I have had in this and in other churches a band of ministerial brethren, older and younger, with whom it has been a life-long privilege to be associated; and in the professors a body of colleagues so generous and loving that greater harmony could not be conceived. The congregations to which I have preached have far overpaid my labours; and the students whom I have taught have given me more lessons than many books. I have been allowed many opportunities of mingling with Christians of other lands, and have learned, I trust, something more of the unity in diversity of the creed, 'I believe in the Holy Catholic Church.' In that true Church, founded on Christ's sacrifice and washed in His blood, cheered by its glorious memories and filled with its immortal hopes, I desire to live and die. Life and labour cannot last long with me; but I would seek to work to the end for Christian truth, for Christian missions, and for Christian union. Amidst so many undeserved favours, I would still thank God and take courage, and under the weight of all anxieties and failures, and the shadows of separation from loved friends, I would repeat the confession, which, by the grace of God, time only confirms: 'In Te, Domine, speravi; non confundar in aeternum.'"