Linus Pauling was one of the most influential chemists in history, uniquely winning two unshared Nobel Prizes (Chemistry and Peace). His genius was centered on quantum chemistry and molecular biology. He published 'The Nature of the Chemical Bond,' which explained how atoms share electrons to form molecules using concepts like electronegativity and resonance. Pauling was a pioneer in understanding the structure of proteins, discovering the alpha-helix—the spiral shape found in many protein molecules. He was also a passionate advocate for nuclear disarmament. His work on the molecular basis of sickle cell anemia was the first time a disease was traced back to a specific molecular abnormality.