'Did he begin with regeneration?' Dr. John Duncan, of the New College, asked his daughter, one Sabbath when she had come home from church full of praise of a sermon she had just heard on sanctification. Dr. Duncan was perhaps the deepest divine this century has seen in Edinburgh; and his divinity took its depth from the same study and the same exercise that Rutherford recommended to John Meine. Dr. Duncan 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.'