Do no harm

‘First, do no harm.’

You may be familiar with this aphorism, which in the last hundred years or so has become the unofficial motto of medical ethics. Almost all young doctors will hear the phrase at an early stage of their training – a useful encapsulation of a central tenet of medicine, that the physician (or surgeon) should consider the possible hurt that an intervention might cause as well as its potential benefits. The neurosurgeon Henry Marsh even gave his bestselling memoir the title Do No Harm.

But where did this catchy phrase come from?

The aphorism is a translation of the Latin primum non nocere. In this form you will often see it referred to as the Hippocratic injunction, and many people assume that it has its origins in the Hippocratic Corpus, the body of early medical texts attributed to the ancient Greek physician Hippocrates and his followers. And there is indeed a similar form of words in the Hippocratic Oath, which affirms that ‘I will abstain from all intentional wrongdoing and harm’. Elsewhere in the Hippocratic Corpus (in a work entitled the Epidemics) there is the instruction ‘either help or do not harm the patient’.

But is it really Hippocratic? The attribution is far from clear. Firstly, although the sentiment is very similar, the form of words is rather different. And, more obviously, the Hippocratic Corpus and Oath are both in Greek. Where, then, did the Latin phrase come from?


I recently read David Wootton’s fascinating book Bad Medicine: Doctors doing harm since Hippocrates. Wootton’s argument, which proved controversial on publication 13 years ago, is essentially that until they came to terms with the implications of germ theory in the 1860s, physicians did more harm than good to their patients. It is a chronicle of failure: Wootton highlights the many occasions on which doctors missed opportunities to translate the discoveries of basic science into meaningful therapeutic interventions. It’s a readable but learned work which demonstrates convincingly how medical science remained in the thrall of ancient doctrines long after they had ceased to be tenable.

In Chapter 9 of Bad Medicine, Wootton suggests that primum non nocere was an invention of the nineteenth century:

This new awareness of just how dangerous medical intervention could be is usefully marked by the coining of the phrase primum non nocere, ‘first do no harm’. The first person to use it was Thomas Inman, who claimed (mistakenly) to be quoting Thomas Sydenham. But the phrase was quickly picked up and attributed not to Sydenham but to Hippocrates – despite the fact that Hippocrates wrote in Greek, not Latin. In reality it is an invention of 1860 and its rapid attribution to Hippocrates represents the invention of a tradition. Newly aware of the extent to which doctors were capable of doing harm, the medical profession reassured themselves with the thought that Hippocrates had shared their concern.

Wootton’s source for this assertion is a paper published in 2005 by the pharmacologist Cedric M. Smith. After a careful search of the literature, Smith ruled out Hippocrates and another celebrated ancient medical writer, Galen, as the source of the phrase. The earliest citation he uncovered was Thomas Inman’s Foundation for a New Theory and Practice of Medicine (1861, although Smith gives 1860 as the publication year). This, he suggests, is how primum non nocere entered medical phraseology. Wikipedia has come to the same conclusion.

But I believe that this conclusion is incorrect. In fact, far from being coined in the 1860s, primum non nocere was being regularly quoted by medical writers half a century earlier. And the origin of the Latin phrase in its modern form appears to be a text written more than 1500 years ago.

Cedric M. Smith based his research on painstaking searches of digitised medical papers and textbooks. Digitisation has moved on considerably in the last 15 years, and a far greater range of text is available now than when his paper was written. It took me very little time to discover that that the phrase primum non nocere was used by many medical writers in English, French and German in the early nineteenth century. It even appears in the preface of a work by Jean-Jacques-Joseph Leroy d’Etiolles, a great French urologist and pioneer of lithotripsy. In Urologie (1845), Leroy d’Etiolles writes:

…avant tout, ne pas nuire; primum non nocere, tel est le précepte que j’ai toujours eu devant les yeux.

(‘Above all, to do no harm; primum non nocere, this is the precept that I have always kept in mind.’)

And this is far from the earliest example. The motto even appears on the title page of a treatise on typhus, Beiträge zur Lehre von den typhösen Fiebern hauptsächlich in Bezug auf ihre Behandlung, by Hugo Leonard von Gützeit (1842) – so it must have been reasonably familiar to physicians by that date.

Four years earlier, in his treatise Studien im Gebiet der Heilwissenschaft (1838), the German surgeon Johann Ferdinand Heyfelder wrote this about the pharmacological treatment of gynaecological conditions:

What abuse was not made during a short time with iodine and with arsenic, whose pernicious effects on the stomach have finally been recognised?  Primum non nocere, deinde prodesse.

You will notice that the aphorism has now acquired a second half, deinde prodesse (‘first do no harm, then do good’). This is a significant addition, of which more later.

These are only a handful of examples, but there are many others in the medical literature from the 1830s and 1840s. Significantly, several imply that they all have a common source. In an important textbook of eye surgery published in 1838, Chirurgie oculaire, the French surgeon Charles Deval offers this advice:

As we must above all conform to the adage primum non nocere, which, as Boyer says, is the first precept of our art, we would never advise the operation to a person with a unilateral cataract.

Deval’s point is well made: as long as a patient has one good eye, operating on the other to relieve a cataract represents an unacceptable risk – at least, in an era before effective control of infection. But what of Boyer, the author he alludes to?

Alexis Boyer was an eminent French surgeon of the early nineteenth century, household surgeon to Napoleon and several French monarchs. In 1814 he published Traité des maladies chirurgicales et des opérations qui leur conviennent. In a chapter devoted to cataract surgery, he advises against early intervention, suggesting that premature operation can do more harm than good:

By operating [at this stage] one would act against the first precept of the art: primum non nocere.

This 1814 quotation is the earliest use of the Latin phrase that I have been able to trace in the medical literature. Interestingly, the second oldest comes in an article by one of Boyer’s colleagues, a contemporary Parisian surgeon who was undoubtedly familiar with Boyer’s work. In an article published in 1829, J.B.H. Dance writes that

The first duty of the surgeon, before that of healing, is not to do harm (primum non nocere).

Boyer was an influential figure: his work was widely read outside France and often quoted by the leading British, German and American surgeons. In 1834 a Spanish textbook on eye surgery included a translation of a large chunk of his Traité des maladies, including the primum non nocere aphorism. Given his stature and international reach, I suggest that it is Alexis Boyer, not Thomas Inman, who popularised the phrase primum non nocere.

But where did Boyer get it from? I mentioned earlier that Cedric M. Smith, in his article on the subject, ruled out Hippocrates on the grounds that the great Greek physician did not write in Latin. The problem with this observation is that for centuries Latin was the lingua franca of Western medicine. Many of the medics educated at European universities between the middle ages and the eighteenth century would have read Hippocrates, Galen and other ancient authors in Latin translation.

A Greek-Latin medical dictionary compiled by Bartholomeo Castellus and published in 1713 quotes a sentence from Hippocrates’ Epidemics in Greek, before translating it into Latin as prodesse, aut non nocere (‘do good, or at least do not cause harm.’). That phrase non nocere was evidently familiar to classically-educated medics, since variations on the theme crop up repeatedly in early modern medical texts. One is saltem non nocere (‘at least do no harm’); another primo non nocere (identical in meaning to the primum version). Both are evidently derived from Hippocrates in the Epidemics.

One more example, predating the Boyer quotation, is significant, although not originally published in Latin. In 1779 another Frenchman, Samuel Auguste André David Tissot, published Traité des nerfs et de leurs maladies, one of the classic texts of neurology. In his preface, Tissot writes that ne pas nuire doit être le premier objet de la médecine (‘not to do harm must be the first priority of medicine.’)

Tissot was writing in French at a time when many of his contemporaries still preferred to publish their work in Latin. A few years later, in a treatise written in Latin, the German physician Balthasar Ludwig Tralles included a substantial quotation from Tissot’s preface, translated verbatim. It ends:

NON NOCERE, primarium obiectum medicinae esse debet.

The capitals are in the original, indicating that Tralles knew that the phrase would be familiar to his readers. To emphasise the point, he then departs from Tissot’s original: Scripserat nempe iam HIPPOCRATES… (‘Thus indeed wrote Hippocrates…’)

That’s the non nocere bit. But what about the primum? There’s an intriguing hint about its origins in an influential textbook of paediatrics, Evanson and Maunsell’s A Practical Treatise on the Management and Diseases of Children. This work, first published in 1836, ran to many editions on both sides of the Atlantic. The first chapter of that work concludes:

Finally, we know no better advice wherewith we can accompany the tender of our work to the public, than that which is contained in the pithy maxim, written over the door of his consultation-room, by a physician of old: Primum est non nocere; secundum prodesse.

Let our first consideration be, how we shall do no mischief; our second, how we shall do some good.

Who was this ‘physician of old’?  It has been suggested that it was Thomas Sydenham, the seventeenth-century doctor known as the English Hippocrates. But primum non nocere does not appear in his writings, and there is no good evidence that he ever used the phrase. However, Evanson and Maunsell append the phrase secundum prodesse (‘secondly, do good’) – similar to the addition made by Heyfelder two years later. This may be the key to the whole mystery, since it appears to be a deliberate echo of a work composed a millennium and a half earlier.

Lucius Caecilius Firmianus Lactantius was an early and influential Christian writer. A Berber born in north Africa, he travelled widely and became a close associate of Constantine, the first Roman emperor to convert to Christianity. Around 310 AD Lactantius wrote Institutiones Divinae (‘The Divine Institutes’), a work intended to explain and promote Christianity to those who had not yet converted. He later produced a condensed version of the text, Epitome Institutionum Divinarum. In chapter 60, which deals with Christian justice, we find this sentence:

Primum est enim non nocere, proximum prodesse.

(‘The first thing is to do no harm, the next is to do good.’)

The similarity with the quotation from Evans and Maunsell is surely too great to be coincidental.

Lactantius was a hugely erudite scholar, familiar with a wide range of Latin, Greek, Hebrew and Egyptian literature. He also had an interest in medicine, since he comments elsewhere on the physiology of Aristotle. It is entirely likely that he knew parts of the Hippocratic Corpus and in particular the Epidemics: Galen, the Greco-Roman physician who lived a century before Lactantius, wrote a detailed commentary on the work which was widely circulated. Lactantius was not writing about medicine, but appears to have found the Hippocratic injunction to Do No Harm a convenient form of words for his own thoughts about morality.

The name of Lactantius is not a familiar one today, unless you happen to be a historian of philosophy or an expert in Christian apologetics. But to an early modern scholar he was an important thinker, a Church Father and polymath. His work was continuously available in print from the late fifteenth century on, and would have been read by many students who went on to practice medicine – particularly in an era when the texts of Galen, Celsus (and commentaries on those works) were still central to medical education.

Title page of early 16th-century edition of Lactantius

So where does this all get us? Firstly, it seems pretty certain that the phrase non nocere (‘do no harm’) was well known to educated medics by the turn of the nineteenth century; and that most would have understood it to be an allusion to Hippocrates. It appears in a multitude of forms in English, French, German and Latin, suggesting it had wide currency. More importantly, at least two authors of the mid-nineteenth century appear to have used primum non nocere in allusion to the work of Lactantius, a writer familiar to earlier readers but little read today.

Strangely, we have come full circle. I began by attempting to debunk the old chestnut that primum non nocere is Hippocratic. But the debunker has been debunked, since it seems that the old aphorism is indeed Hippocratic, albeit filtered through the mind of an early Christian writer from North Africa, writing in Latin almost 1700 years ago.

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