Alexander Solzhenitsyn, who had every reason in the world to be bitter, to hate this group or that, never was and never did. His Christian faith transcended that and he was able, after all his sufferings, not to demand an eye for an eye but to speak the truest words any Christian has ever spoke:
It was only when I lay there on rotting prison straw that I sensed within myself the first stirrings of good. Gradually it was disclosed to me that the line separating good and evil passes not through states, nor between classes, nor between political parties either, but right through every human heart, and through all human hearts. This line shifts. Inside us, it oscillates with the years. Even within hearts overwhelmed by evil, one small bridgehead of good is retained; and even in the best of all hearts, there remains a small corner of evil.
These words of Solzhenitsyn, perhaps unwittingly, evoke the core of centuries-old Roman Catholic teaching that man is of two natures -- one good -- one evil. The two are always in conflict and it takes diligence, faith and fortitude to keep on the side of good. (I've read all of Solzhenitsyn's works and, I could be wrong, but I do not believe Catholic teaching influenced him. It's the genius of the man to have come up with the dual nature of man concept.)
Non-believer Sigmund Freud "filched" the Catholic concept when he wrote of the "inner room" of the mind.......which Christians know as "conscience" sorting out the conflicts within us.
And nobody has ever written of man's duelling inner forces better than genius author C.S. Lewis (a Catholic) in his remrkable book, The Screwtape Letters.