He was an immense reader also; but neither was it the piles of books; it was, he tells us, first the new heart that he got as a student in Aberdeen, and then it was the lifelong conflict that went on within him between the old heart and the new.  And it is this that makes sanctification rank and stand out as the first and the oldest of all the experimental sciences.  Long before either of the Bacons were born, the humblest and most obscure of God’s saints were working out their own salvation on the most approved scientific principles and methods.  Long before science and philosophy had discovered and set their seal to that method, the Church of Christ had taught it to all her true children, and all her best divines had taken a deep degree by means of it.  What experimentalists were David and Asaph and Isaiah and Paul; and that, as the subtlest and deepest sciences must be pursued, not upon foreign substances but upon themselves, upon their own heart, and mind, and will, and disposition, and conversation, and character.  Aristotle says that ’Young men cannot possess practical judgment, because practical judgment is employed upon individual facts, and these are learned only by experience, and a youth has not experience, for experience is gained only by a course of years.’

‘A truly great divine,’ was Jonathan Edwards’ splendid certificate to our own Thomas Boston.  Now, when we read his Memoirs, written by himself, we soon see what it was that made Boston such a truly great and deep divine.  It was not the number of his books, for he tells us how he was pained when a brother minister opened his book-press and smiled at its few shelves.  ‘I may be a great bookman,’ writes Rutherford to Lady Kenmure, ‘and yet be a stark idiot in the things of Christ.’  It was not his knowledge of Hebrew, though he almost discovered that hidden language in Ettrick.  No, but it was his discovery of himself, and his experimental study of his own heart.  ’My duties, the best of them, would damn me; they must all be washed with myself in that precious blood.  Though I cannot be free of sin, God Himself knows that He would be welcome to make havoc of all my lusts to-night, and to make me holy.  I know no lust I would not be content to part with to-night.  The first impression on my spirit this morning was my utter inability to put away sin.  I saw that it was as possible for a rock to raise itself as it was for me to raise my heart from sin to holiness.’

But the study of divinity is not a close profession:  a profession for men only, and from which women are shut out; nor is the method of it shut off from any woman or any man.  ‘I counsel you to study sanctification,’ wrote Rutherford, the same year to the Lady Cardoness.  And if you think that Rutherford was a closet mystic and an unpractical and head-carried enthusiast, too good for this rough world, read his letter to Lady Cardoness, and confess your ignorance of this great and good man.  ’Deal