Isaac Leibowitz is a central character in the science fiction novel "A Canticle for Leibowitz" by Walter M. Miller Jr.. He is a Jewish engineer who becomes a monk in the Albertian Order of Leibowitz after a nuclear apocalypse devastates civilization. His character symbolizes the preservation of knowledge and culture in a world that has fallen into chaos. Throughout the story, Leibowitz's efforts to safeguard ancient texts and artifacts highlight the importance of memory and learning. His legacy continues to influence future generations as they grapple with the cyclical nature of history and the potential for humanity to repeat its mistakes.