This chapter, Medical Ethics and Its Evolution in Surgical Practice, by Alberto R Ferreres traces how theoretical reflections on morality became the practical rules that govern everyday surgical care. Beginning with ancient “oaths of faith,” advancing through professional “oaths of decorum,” and arriving at modern codes of deontology, the narrative shows how surgeons moved from obedience to higher powers toward deliberate moral agency. Today, medical ethics is best understood as the disciplined use of moral theories, principles, and virtues to guide physicians—and especially surgeons—in patient care, research, education, and leadership. Because the surgical craft is uniquely invasive, surgical ethics forms a recognizably separate branch of medical ethics.