Is 'First Do No Harm' Part of the Hippocratic Oath?

What's the Origin of This Popular Medical Ethics Dictum?

Doctor holding a stethoscope standing before a white background.

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The expression "first do no harm" is a popular term used to express the underlying ethical rules of modern medicine. Although this is generally thought to have been taken from the ancient Greek Hippocratic oath, no translations of the oath contain this language. 

Key Takeaways

  • The expression "first do no harm," which is a Latin phrase, is not part of the original or modern versions of the Hippocratic oath, which was originally written in Greek. 
  • The Hippocratic oath, written in the 5th century BCE, does contain language suggesting that the physician and his assistants should not cause physical or moral harm to a patient. 
  • The first known published version of "do no harm" dates to medical texts from the mid-19th century, and is attributed to the 17th century English physician Thomas Sydenham. 

What Does 'First Do No Harm' Mean?

"First do no harm" is a popular saying that derives from the Latin phrase, "primum non nocere" or "primum nil nocere." The term is particularly popular amongst those involved in the field of healthcare, medicine, or bioethics, and among popular accounts of the medical field, since it is a basic principle taught in healthcare-providing classes.

The takeaway point of "first do no harm" is that, in certain cases, it may be better to do nothing rather than intervening and potentially causing more harm than good. 

History of the Hippocratic Oath 

The Hippocratic oath is part of an outline of essential ethics in medicine which is described in ancient Greek literature.

Hippocrates was a Greek physician who lived on the island of Cos between about 460-370 BCE. He wrote many medical texts and is considered one of the most important figures in ancient Greek medicine. He is generally credited with writing the original Hippocratic Oath. 

The oldest extant mention of the Hippocratic Oath was found on a medical papyrus dated to the 5th century CE, one of the many thousands of manuscripts found in the archaeological treasure trove Oxyrhynchus. The oldest extant version is from the 10th century CE. It is stored in the Vatican library. The original is thought to have been a written law of the medical fraternal organization on the island of Cos, of which Hippocrates was a member. Written in Greek about 421 BCE, the oath was originally intended as a pledge between a master (the physician) and his qualified assistants. 

The Original Purpose of the Oath

Healers in Athenian society were known as Asclepiads and they belonged to a guild (koinon), to which they inherited their right of membership from their fathers. Hippocrates' father and grandfather before him were members of the guild on Cos. Then, doctors were itinerant specialists who carried their skills from city to city, setting up surgeries. Rather than a promise made by new doctors on joining the guild, the oath was sworn by nurses and assistants in the various surgeries as part of a promise to obey the doctor. 

According to the original Hippocratic oath, these assistants were to respect their masters, share medical knowledge, help patients and avoid harming them medically or personally, seek help from other physicians when necessary, and keep patient information confidential.  

However, there is no mention of the phrase "first do no harm" in the original oath.

Hippocratic Oath in Modern Usage

Although "first do no harm" does not actually come from the Hippocratic oath verbatim, it can be argued that it does come from that text in essence. That is, similar ideas are conveyed in the text of the Hippocratic Oath. Take, for example, this related section which has been translated as:

I will follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous. I will give no deadly medicine to anyone if asked, nor suggest any such counsel, and in like manner I will not give to a woman a pessary to produce abortion. 

In reading the Hippocratic oath, it is apparent that not harming the patient is explicit. However, it is not clear that "abstain from whatever is deleterious" is equivalent to "doing no harm." 

Of the Epidemics

A closer version to the succinct "do no harm" does come (possibly) from Hippocrates, however. "Of the Epidemics" is a part of the Hippocratic Corpus, which is a collection of ancient Greek medical texts written between 500 and 400 BCE. Hippocrates was never proven to be the author of any of these works, but the theories do follow closely with Hippocrates' teachings.

Regarding "first do no harm," "Of the Epidemics" is considered to be the more likely source of the popular saying. Consider this quote:

The physician must be able to tell the antecedents, know the present, and foretell the future — must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm. 

However, according to an exhaustive search of the ancient and historical literature conducted by pharmacologist Cedric M. Smith, the phrase "primum non nocere" does not appear in medical texts until the mid-19th century, when it is attributed to the 17th century English physician Thomas Sydenham. 

The Hippocratic Oath

At many medical schools, but by no means all, a version of the Hippocratic oath is given to the student on graduation or read to the students in the first year. Different countries have different customs about the oath. In French medical schools, it is common to have the student sign the oath on graduation. In the Netherlands, students must swear to it verbally. 

At graduation, some deans read the oath while the students stand silent. In others, the students repeat a modern version of the oath at the graduation ceremony. However, data on these reports do not tell how often "primum non nocere" is included as part of the oath. 


Crawshaw, Ralph. "The Hippocratic Oath [with Reply]." BMJ. BMJ: British Medical Journal, T. H. Pennington, C. I. Pennington, et al., Vol. 309, No. 6959, JSTOR, October 8, 1994.

Jones, Mary Cadwalader. "The Hippocratic Oath." The American Journal of Nursing. Vol. 9, No. 4, JSTOR, January 1909. 

Nittis, Savas. "The Authorship and Probable Date of the Hippocratic Oath." The Johns Hopkins University Press. Bulletin of the History of Medicine, Vol. 8, No. 7, JSTOR, July 1940.

Shmerling, Robert H., MD. "The Myth of the Hippocratic Oath." Harvard Health Publishing. Harvard Medical School, Harvard Health Blog, Harvard University, November 28, 2015.

Smith, Cedric M. "Origin and Uses of Primum Non Nocere — Above All, Do No Harm!" The Journal of Clinical Pharmacology, Volume 45, Issue 4, American College of Clinical Pharmacology, John Wiley & Sons, Inc., March 7, 2013.

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Gill, N.S. "Is 'First Do No Harm' Part of the Hippocratic Oath?" ThoughtCo, Feb. 16, 2021, Gill, N.S. (2021, February 16). Is 'First Do No Harm' Part of the Hippocratic Oath? Retrieved from Gill, N.S. "Is 'First Do No Harm' Part of the Hippocratic Oath?" ThoughtCo. (accessed June 5, 2023).