Five and thirty further years have run their course. Mr. Erskine is now seventy-three. He has passed through the fires of persecution, and, in days of tumult and unrest, has proved himself a leader whom the people have delighted, at any cost, to follow. But his physical frame is exhausted. An illness overtakes him which, continuing for over a year, at last proves fatal. His elders drop in from time to time to read and pray with him. To-day one of them, the senior member of the little band, is moved, in taking farewell of his dying minister, to ask a question of him. After grasping the sick man's hand and moving towards the door, a sudden impulse seizes him and he returns to the bedside. 'You have often given us good advice, Mr. Erskine,' he says, 'as to what we should do with our souls in life and in death; may I ask what you are now doing with your own?' 'I am just doing with it,' the old man replies, 'what I did forty years ago; I am resting it on that word, "_I am the Lord thy God!_"' V Now what was it, I wonder, that Ebenezer Erskine saw in this string of monosyllables as he sat on the fallen slab beside the ruined abbey in 1690, as he sat conversing with his convalescent wife in 1708, as he preached with such passion in 1718, and as he lay dying in 1753? What, to him, was the significance of that great sentence that, as the catechism says, forms '_the preface to the Ten Commandments_'? Ebenezer Erskine saw, underlying the words, two tremendous principles. They convinced him that _the Center must always be greater than the Circumference_ and they convinced him that _the Positive must always be greater than the Negative_. _The Center must always be greater than the Circumference_, for, without the center, there can be no circumference. And there, in the very first word of this 'preface to the Ten Commandments,' stands the august center around which all the mandates revolve. '_I_ am the Lord thy God.' 'I have many times essayed,' Luther tells us in his _Table-Talk_, 'thoroughly to investigate the Ten Commandments; but at the very outset--"_I am the Lord thy God_"--I stuck fast. That single word "_I_" put me to a non-plus.' I am not surprised. The man who would enter this Palace of Ten Chambers will find God awaiting him on the threshold; and he must make up his mind as to his relationship with Him before he can pass on to investigate the interior of the edifice. In learning his Shorter Catechism that Sunday morning at Dryburgh, Ebenezer Erskine, then a boy of ten, had come face to face with God; and he felt that he dared not proceed to the _Circumference_ until his heart was in harmony with the _Center_. VI