Guy Leschziner's Seven Deadly Sins: The Biology of Being Human explores the neurological and biological underpinnings of seven classic sins. The book examines how brain structure, chemistry, and activity influence behaviors such as anger, gluttony, lust, envy, sloth, greed, and pride. Leschziner uses case studies of patients with various neurological conditions to illustrate his points, showing how these conditions can amplify or alter behaviors related to the seven sins. He also discusses the evolutionary basis for these traits and the societal implications of their extremes. The book concludes by considering the complex relationship between biology, free will, and moral responsibility.