Yes, it’s the ancient “first do no harm”.

the Hippocratic Oath

It isn’t explicitly in the Hippocratic Oath that physicians use to take, but it summarizes a very important part of it: do nothing that to your knowledge might harm the patient. No sensible person would dare argue such a statement, ever. But still…
Let’s face it: had it been taken literally over the course of human history, medically speaking today we’d still be at square one – faith, hope, arcane chanting, harmless rituals and little more.
Yet there must have been quite a number of medicine men and sorcières plagued by doubt: “For all I know this guy will die in a couple of days unless I do something. I believe that this potion can help him, but chances are that it proves lethal. If I’m wrong I’ll rob him of just a few atrocious days, but if I’m right I’ll get him back the rest of his life. To hell with it, I’ll take the risk!”.

The art of survival

As neither the humankind nor the medical profession is extinct today, we can conclude that quite a share of those brave people were right (or lucky, if you wish): with time their experience built an impressive wealth of knowledge, medical techniques, effective medicines and treatments. Come to think of it, ‘experience’ and ‘experiment’ share the same root in most languages after all… 🙂
But how about the physicians who tried and DIDN’T succeed?
Until a few centuries ago, nothing: their failures were ascribed to God’s will, most of them were members of some powerful guild that would protect them against possible suspicion, and dead people don’t talk. Only a few ended up burned at the stake, though traditionally accused of witchcraft rather than of malpractice.

Witches preparing a potion with snakes

Historical evidence

Only a couple of centuries ago things changed drastically. Dead people don’t talk but books do: while flipping through those old moldy medical tomes it’s hard not to cringe before some utterly gruesome images depicting the state-of-the-art in matter of medicine and surgery, and one cannot help but wonder how those patients could survive the ailment AND the treatment. The answer is, probably not many made it. Nevertheless those books weren’t written by the butcher next door, they were signed by illustrious physicians, surgeons and scientists at the time, people no one would dare contradict or criticize because no one knew as much.

The first electric baths were introduced at the Hopital de la Pitie in Paris by Bequerel.
Many users survived and some even enjoyed the experience, although the physicians at the time weren’t unanimous about the benefits of this practice

Dr. Computer

Now medicine is drifting inexorably (if damn slowly) from art to science, and probably in a near future the feared day will come when “the doctors think he has…” will be replaced by “the medical computer has determined that the patient suffers from…”. Let’s just hope that the basic rules such a medical computer is constrained by, beside the “first do no harm”, also include a precautionary “if it ain’t broken don’t fix it” 🙂