This from the front-piece of this book:
"Hugh Ross Mackintosh, born in 1870, was in his day one of the best loved and widely influential of Scottish theologians. His distinguished university career in Edinburgh was followed by specialised studies in philosophy as Marburg. He had great sympathy with movement in German theology and made it one of his chief objects to familiarise Britain with them...In 1904 he was appointed professor of systematic theology at new College, Edinburgh as was elected Moderator of the General Assembly of the Church of Scotland in 1932."
“When, however, we survey the world of humanity, when we look into our own breast, what is it that we fine? Anything else than such a normal and continuous development of life, unfolding to the fullness of perfected powers. We find, instead, the universal phenomenon of man’s nature divided against itself, at variance with neighbour and with God. If our true destiny is to obey, it is a destiny we are obviously unable to accomplish. It is not simply that we freely reject the Higher Will; we discover that to accept it gladly is beyond us. All who reach moral personality learn, on the faintest self-scrutiny, that their moral being is somehow wrong and crooked; that along side of the commanding sense of obligation there are fermenting within them a set of half-blind and half-perverted instincts, evil tendencies which solicit their choice, lead their will astray, and often master it shamefully. In short, we cannot begin the life of moral struggle and consent to face ourselves without feeling within us the dreary pain of the bad conscience—without becoming aware, that is, that our will is evil. It is not wholly evil, as we shall see, but evil taints it in every element. Thus the fatal distinction between what we are and what we ought to be comes home to us. We are forced to look with open eyes on the one hand at our moral obligations, on the other at our moral incapacity. Both experiences are our own—the sense of what we are, thrust on us by a corrupt nature. It is an internal schism, a rupture in the unity of the self; and in consequence the self becomes so far a scene of anarchy and impotence. And in the last resort we are divided in ourselves because we are sundered from Him in whose will is our peace. To be alienated from God, for whose service and obedience we were made, is the invariable antecedent of that unseen tie, if unrepaired by forgiveness, will bring every candid man to the avowal that he is dragging with him through life a weight of unmanageable and perverse evil, which in some sense he must own as his and cannot disown.
This wrong state or attitude of the will is called “sin” by all who acknowledge its reality…” (pp 52-53)