by me both from your instructions and private friendship, I am more indebted to you for the foundation of my intellectual habits and tastes than to any other person, and shall bear, by the will of the Almighty, the impress of your hand through any future stage of existence.  It is a relief to my own feelings to speak in this manner, and you will forgive one of the most favoured of your pupils if he seeks another kind of relief—­a relief which he has long sought an opportunity to obtain—­the expression of a wish that his honoured master were one with himself in the exercise of the convictions, and the enjoyment of the comforts, of living Christianity, or as far before himself as he is in all other particulars.  This is a wish, a prayer, a fervent desire often expressed to the Almighty Former and Guide of the spirits of men, mingled with the hope that, if not already, at least some time, this accordance of faith will be attained, this living union realised with the great Teacher, Sacrifice, and Restorer of our fallen race.  You will pardon this manifestation of the gratitude and affection of your pupil and friend, who, if he knew a higher, would gladly give it as a payment of a debt too great to be expressed.  I have long ago been taught to feel the vanity of the world in all its forms—­to renounce the hope of intellectual distinction, and to exalt love above knowledge.  Philosophy has been to me much; but it can never be all, never the most; and I have found, and know that I have found, the true good in another quarter.  This is mysticism—­the mysticism of the Bible—­the mysticism of conscious reconciliation and intimacy with the living Persons of the Godhead—­a mysticism which is not like that of philosophy, an irregular and incommunicable intuition, but open to all, wise and unwise, who take the highway of humility and prayer.  If I were not truly and profoundly happy in my faith—­the faith of the universal Church—­I would not speak of it.  The greatest increase which it admits of is its sympathetic kindling in the hearts of others, not least of those who know by experience the pain of speculation, the truth that he who increaseth knowledge increaseth sorrow.  I know you will indulge these expressions to one more in earnest than in former years, more philanthropic, more confident that he knows in whom he has believed, more impressed with the duty of bearing everywhere a testimony to the convictions which have given him a positive hold at once of truth and happiness.

“But I check myself in this unwonted strain, which only your long-continued and singular kindness could have emboldened me to attempt; and with the utterance of the most fervent wishes for your health, academical success, and inward light and peace, I remain your obliged friend and grateful pupil.”

To which Sir W. Hamilton replied as follows:—­

“EDINBURGH, Dec. 4, 1848.

“I feel deeply obliged to you for the kindness of your letter, and trust that I shall not prove wholly unworthy of the interest you take in me.  There is indeed no one with whom I am acquainted whose sentiments on such matters I esteem more highly, for there is no one who, I am sure, is more earnest for the truth, and no one who pursues it with more independence and, at the same time, with greater confidence in the promised aid of God.  May this promised aid be vouchsafed to me."[7]