Four years later Sir William Hamilton died, and a fierce fight ensued as to who was to be his successor.  The two most prominent candidates were Cairns’s friend Campbell Fraser, then Professor of Logic in the New College, Edinburgh, and Professor James Frederick Ferrier of St. Andrews.  Fraser was then a Hamiltonian and Ferrier was a Hegelian, and a great hubbub arose between the adherents of the two schools.  This was increased and embittered by the importation of ecclesiastical and political feeling into the contest; Fraser being a Free Churchman, and Ferrier receiving the support of the Established Church and Tory party.  The Town Council were very much at sea with regard to the philosophical controversy, and, through Dr. John Brown, they requested Cairns to explain its merits to them.  Cairns responded by publishing a pamphlet entitled An Examination of Professor Ferrier’s Theory of Knowing and Being.  This pamphlet had for its object to show that Ferrier’s election would mean a renunciation of the doctrines which, as expounded by Hamilton, had added so greatly to the prestige of the University in recent times as a school of philosophy, and also to expose what the writer conceived to be the dangerous character of Ferrier’s teaching in relation to religious truth.  It increased the storm tenfold.  Replies were published and letters sent to the newspapers abusing Cairns, and insinuating that he had been led by a private grudge against Ferrier to take the step he had taken.  It was also affirmed that he was acting at the instigation of the Free Church, who wanted to abolish their chair of Logic in the New College, but could not well do so so long as they had its present incumbent on their hands.  A doggerel parody on John Gilpin, entitled “The Diverting History of John Cairns,” in which a highly coloured account is given of the supposed genesis of the pamphlet, was written and found wide circulation.  The first two stanzas of this effusion were the following:—­

  “John Cairns was a clergyman
    Of credit and renown,
  A first-rate U.P.  Church had he
    In far-famed Berwick town.

  John likewise had a loving friend,
    A mighty man of knowledge,
  The Rev. A.C.  Fraser, he
    Of the sanctified New College.”

Cairns found it needful to issue a second pamphlet, Scottish Philosophy:  a Vindication and Reply, in which, while tenaciously holding to what he had said in the last one, he challenged Ferrier to mention one single instance in which he had made a personal attack on him.  When at length the vote came to be taken, and Fraser was elected by a majority of three, there were few who doubted that the intervention of the Berwick minister had been of critical importance in bringing about this result.