The philosophy of Friedrich Nietzsche rather prominently includes the idea of the Übermensch ("overman" or "superman"), who were exempt from the ordinary rules of morality in some sense. Is this what the following passage from The Magician's Nephew is referring to? Does Uncle Andrew consider himself an Übermensch?
"All in good time, my boy," said Uncle Andrew. "They let old Mrs. Lefay out before she died and I was one of the very few people whom she would allow to see her in her last illness. She had got to dislike ordinary, ignorant people, you understand. I do myself. But she and I were interested in the same sort of things. It was only a few days before her death that she told me to go to an old bureau in her house and open a secret drawer and bring her a little box that I would find there. The moment I picked up that box I could tell by the pricking in my fingers that I held some great secret in my hands. She gave it to me and made me promise that as soon as she was dead I would burn it unopened, with certain ceremonies. That promise I did not keep."
"Well then, it was jolly rotten of you," said Digory.
“Rotten?” said Uncle Andrew with a puzzled look. “Oh, I see. You mean that little boys ought to keep their promises. Very true: most right and proper, I’m sure, and I’m very glad you have been taught to do it. But of course you must understand that rules of that sort, however excellent they may be for little boys—and servants—and women—and even people in general, can’t possibly be expected to apply to profound students and great thinkers and sages. No, Digory. Men like me, who possess hidden wisdom, are freed from common rules just as we are cut off from common pleasures. Ours, my boy, is a high and lonely destiny.”