His ideal at first was of one great Presbyterian Communion co-extensive with the English language, and separately organised in the different countries and dependencies in which its adherents were to be found, but having one creed and one form of worship and complete freedom from all State patronage and control.  But, as the times did not seem ripe for such a vast consummation, he made no attempt to give his ideal a practical form, and concentrated his energies on the lesser movement which was beginning to take shape for a union of the Presbyterian Churches in England and the non-Established Presbyterian Churches in Scotland.  He was one of those who brought this project before the Synod of the United Presbyterian Church in May 1863, when he appeared in support of an overture from the Berwick Presbytery in favour of Union.  The overture was adopted with enthusiasm, and the Synod agreed by a majority of more than ten to one to appoint a committee to confer with a view to Union with any committee which might be appointed by the Free Church General Assembly.  The Free Church Assembly, which met a fortnight later, passed a similar resolution unanimously, although not without a keen discussion revealing elements of opposition which were afterwards to gather strength.

It is quite possible that, as competent observers have suggested, if the enthusiasm for the project which then existed had been taken advantage of at once, Union might have been carried with a rush.  But the able men who were guiding the proceedings thought it safer to advance more slowly; and, when the Joint Union Committee met, they went on to consider in detail the various points on which the two Churches differed.  These had reference almost entirely to the relations between Church and State.  The United Presbyterians were, almost to a man, “Voluntaries,” i.e. they held that the Church ought in all cases to support itself without assistance from the State, and free from the interference which, in their view, was the inevitable and justifiable accompaniment of all State establishments.  The Free Churchmen, on the other hand, while maintaining as their cardinal principle that the Church must be free from all State interference, and while therefore protesting against the existing Establishment, held that the Church, if its freedom were adequately guaranteed, might lawfully accept establishment and endowment from the State.  An elaborate statement was drawn up exhibiting first the points on which the two Churches were agreed with regard to this question, and then the points on which they differed.  From this it appeared that they were at one as to the duty of the State—­or, in the language of the Westminster Confession, the “Civil Magistrate”—­to make Christian laws and to administer them in a Christian spirit.  The Civil Magistrate ought, it was agreed, to be a Christian, not merely as a man but as a magistrate.  The only vital point of difference was with regard to the question of Church establishments—­as