n was a great
scholar, but it was not his scholarship that made him such a singularly
deep divine. He was a profound philosopher also; but neither was it his
philosophy. 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