The Hippocratic Oath is an oath of guidelines and ethics sworn to by Earth physicians, devised by Hippocrates.
In 2152, when explaining the difference between Denobulan and Human medical ethics, Dr. Phlox stated "Hippocrates wasn't Denobulan". (ENT: "The Breach")
When given the opportunity to kill Unferth in the holodeck, the Doctor told him that the only reason that he wasn't going to kill him was because he had "taken an oath to do no harm." (VOY: "Heroes and Demons") He would later give this as the reason he could not perform the procedure to separate Tuvix (VOY: "Tuvix")
In 2373, the Doctor recited to himself a version of the introduction to the oath which went as follows:
- "I swear this oath by Apollo physician, by Asclepius, by health and by all the gods and goddesses: In whatsoever place that I enter I will enter to help the sick and heal the injured, and I will do no harm." (VOY: "Darkling")
The quote from the USS Pasteur's dedication plaque was the first part of the Hippocratic Oath.
- "I swear by Apollo the healer, by Aesculapius, by Health and all the powers of healing..." (TNG: "All Good Things...")
Certain Malcorian physicians swear to an oath similar to the Hippocratic Oath. Berel specifically states "I have sworn an oath to do no harm. And I will not." (TNG: "First Contact")