Codes, oaths and prayers guiding health practitioners in caring for patients have been extant for centuries. Codes of ethics have been expressed in the form of prayers, oaths, creeds, institutional directives, and statements. "Prayers state a very personal commitment of duty; oaths publically pledge the oath taker to uphold specified responsibilities; and codes provide more comprehensive standards to guide the practicing health practitioner, patient, or other decision maker. Each form of ethical statement implies a moral imperative, either to be accepted by the individual personally or to be enforced by a practitioner organization, religious community, or governmental body." (Veatch, Robert. 1995. "Medical Codes and Oaths" in vol. 1,pp. 1419-1435, Encyclopedia of Bioethics. 2nd ed. New York: Macmillan : Simon & Schuster Macmillan ; Prentice Hall International.
One of the earliest oaths is one for medical students taken from the Charaka Samhita manuscript of ancient India. This oath called upon the student to follow a path of personal sacrifice and commitment to duty. In western Medicine, the Hippocratic Oath has had great influence. The Oath of Asaf, from a seventh-century Hebrew medical manuscript, reveals Hippocratic influences in its injunctions against administering poisons or abortifacient drugs, performing surgery, committing adultery, and betraying practitioner confidences. In China, medical ethics appear in the Taoist writer Sun Szu-miao, whose writing stresses the importance of preserving life and serving the interests of the patient. The most widely known Jewish text is the Daily Prayer of a Physician, once ascribed to the Jewish philosopher and phyisician Moses Maimonides (1135-1204).
A select list of oaths, codes and statements follows. For more information on the history and background of codes and oaths see the entry "Medical Codes and Oaths" in the Encyclopedia of Bioethics referenced above.