Hush, Sonia! I am not laughing. I know myself that it was the devil leading me. Hush, Sonia, hush!” he repeated with gloomy insistence. “I know it all, I have thought it all over and over and whispered it all over to myself, lying there in the dark.… I've argued it all over with myself, every point of it, and I know it all, all! And how sick, how sick I was then of going over it all! I kept wanting to forget it and make a new beginning, Sonia, and leave off thinking. And you don’t suppose that I went into it headlong like a fool? I went into it like a wise man, and that was just my destruction. And you mustn't suppose that I didn't know, for instance, that if I began to question myself whether I had the right to gain power—I certainly hadn't the right—or that if I asked myself whether a human being is a louse it proved that it wasn't so for me, though it might be for a man who would go straight to his goal without asking questions.… If I worried myself all those days, wondering whether Napoleon would have done it or not, I felt clearly of course that I wasn't Napoleon. I had to endure all the agony of that battle of ideas, Sonia, and I longed to throw it off: I wanted to murder without casuistry, to murder for my own sake, for myself alone! I didn't want to lie about it even to myself. It wasn't to help my mother I did the murder—that’s nonsense—I didn't do the murder to gain wealth and power and to become a benefactor of mankind. Nonsense! I simply did it; I did the murder for myself, for myself alone, and whether I became a benefactor to others, or spent my life like a spider, catching men in my web and sucking the life out of men, I couldn't have cared at that moment.… And it was not the money I wanted, Sonia, when I did it. It was not so much the money I wanted, but something else.… I know it all now.… Understand me! Perhaps I should never have committed a murder again. I wanted to find out something else; it was something else led me on. I wanted to find out then and quickly whether I was a louse like everybody else or a man. Whether I can step over barriers or not, whether I dare stoop to pick up or not, whether I am a trembling creature or whether I have the right …”	  “To kill? Have the right to kill?” Sonia clasped her hands. “Ach, Sonia!” he cried irritably and seemed about to make some retort, but was contemptuously silent. “Don’t interrupt me, Sonia. I want to prove one thing only, that the devil led me on then and he has shown me since that I had not the right to take that path, because I am just such a louse as all the rest. He was mocking me and here I've come to you now! Welcome your guest! If I were not a louse, should I have come to you? Listen: when I went then to the old woman’s I only went to try. … You may be sure of that!” “And you murdered her!” “But how did I murder her? Is that how men do murders? Do men go to commit a murder as I went then? I will tell you some day how I went! Did I murder the old woman? I murdered myself, not her! I crushed myself once for all, for ever.… But it was the devil that killed that old woman, not I. Enough, enough, Sonia, enough! Let me be!” he cried in a sudden spasm of agony, “let me be!
— Fyodor Dostoyevsky, Crime and Punishment