Editing Ignaz Semmelweis (section)

===Conflict with established medical opinion===
{{Main|Contemporary reaction to Ignaz Semmelweis}}
[[File:Monthly mortality rates 1841-1849.png|thumb|500px|[[Puerperal fever]] monthly mortality rates for the First Clinic at Vienna Maternity Institution 1841–1849. Rates drop markedly when Semmelweis implemented chlorine [[hand washing]] mid-May 1847 [[Historical mortality rates of puerperal fever#Monthly mortality rates for birthgiving women 1841–1849|(see rates)]].]]

Semmelweis's observations conflicted with the established scientific and medical opinions of the time. The theory of diseases was highly influenced by ideas of an imbalance of the basic "[[Humorism|four humours]]" in the body, a theory known as [[dyscrasia]], for which the main treatment was [[bloodletting]]s. Medical texts at the time emphasized that each case of disease was unique, the result of a personal imbalance, and the main difficulty of the medical profession was to establish precisely each patient's unique situation, case by case.

The findings from autopsies of deceased women also showed a confusing multitude of physical signs, which emphasized the belief that puerperal fever was not one, but many different, yet unidentified, diseases.

The rejection of Semmelweis's empirical observations is often traced to [[belief perseverance]], the psychological tendency of clinging to discredited beliefs. Also, some historians of science{{sfn|Nissani|1995|pp=165–183}} argue that resistance to path-breaking contributions of obscure scientists is common and "constitutes the single most formidable block to scientific advances."

As a result, his ideas were rejected by the medical community. Other, more subtle, factors may also have played a role. Some doctors, for instance, were offended at the suggestion that they should wash their hands, feeling that their social status as gentlemen was inconsistent with the idea that their hands could be unclean.{{sfn|Carter|Carter|2005|p=9}}{{efn-ua|See for instance [[Charles Delucena Meigs]], in which there is a link to an original source document.}}

Semmelweis's results lacked scientific explanation at the time. That became possible only in the 1860s and 1870s, when [[Louis Pasteur]], [[Joseph Lister]], and others further developed the germ theory of disease.

During 1848, Semmelweis widened the scope of his washing protocol, to include all instruments coming in contact with patients in labour, and used mortality rates [[time series]] to document his success in virtually eliminating puerperal fever from the hospital ward.