Ignaz Semmelweis Quotes

Semmelweis reflex: The tendency to reject new evidence or new knowledge because it contradicts established norms, beliefs or paradigms

In the mid-1800s, Dr. Ignaz Philipp Semmelweis noticed that new mothers who were treated by midwives fared much better than those who were treated by trainee doctors, who also handled and dissected cadavers. He believed that sticking one’s hands into a dead body and then directly into a laboring woman was dangerous. So, Semmelweis issued a mandate that hands must be washed between the two activities. And it worked! Rates of infection dropped from one in ten to one in a hundred within the first few months. Unfortunately, the finding was rejected by much of the medical establishment of the time. One of the reasons it was so hard to get doctors to wash up? The stench of “hospital odor” on their hands was a mark of prestige. They called it “good old hospital stink.” Quite simply, decayed corpse smell was a badge of honor they had no intention of removing.

A figure who was much reviled in his own time but whose speculations and medical practice also paved the way for the germ theory was the Hungarian gynecologist Ignaz Philipp Semmelweis (1818–1865). In the 1840s, working at the Vienna General Hospital, Semmelweis was appalled by the rate of maternal mortality from puerperal fever, now known to be a severe bacterial blood infection and then the leading cause of death in lying-in hospitals.

The tragic case of Ignaz Semmelweis highlights that it is not sufficient for a mental frame to improve decision-making. For a frame to catch on, it also has to offer a convincing causal explanation.

When the Viennese doctor Ignaz Semmelweis insisted that delivery room doctors and medical students wash their hands before attending their patients, he was ridiculed, even though the practice dramatically reduced death from puerperal sepsis. In 1865, when Semmelweis died, his simple but radical idea was still discounted.

Ignaz Semmelweis,

Usually, there is no single moment when everything changes. Pasteur’s fermentation experiments did not on their own overturn centuries of error or obliviousness. He had predecessors: eager dreamers like Cotton Mather, observers pursuing the logic of infection like Oliver Wendell Holmes and Ignaz Semmelweis, run-with-what-works empiricists like the Civil War doctors. Truly, there are vanishingly few singular moments of discovery in the history of science. And yet, while the work he would do over the next three decades is better remembered, this one paper, five pages long, is the claxon, the signal that something momentous was happening. Most important, Pasteur had grasped a singular insight, one of the most important since Leeuwenhoek first saw his tiny wriggling forms and recognized them as alive: germs that could turn juice into wine were envoys from the microcosmos at work in our macroscopic world. They could be employed to our benefit in a vat of wine or riot against our interests when beet juice turns sour. And they might do who knows what else for or to the human beings—and societies. Pasteur knew that he was onto something more than a neat bit of industrial research. His work on fermentation had pushed him beyond yeast and deeper into the microbial world. Over the next two decades, he identified a range of creatures that could drive chemical changes in the media that nourished them—like lactobacillus, a bacterium involved in the lactic acid pathway responsible for sour milk, or Mycoderma aceti (which he misidentified as a microscopic plant)—the complex of organisms that includes the bacteria behind the acetic fermentation that gives us vinegar. He discovered the existence of anaerobic bacteria, microbes that live in the absence of air. He showed that it was possible to engineer fermentations by introducing one microbe or another to the fluid to be transformed, producing alcohol or lactic acid or some other product of interest.