Sometimes, however, scientists have refused to examine new evidence which could undermine confidence in an established theory. Possibly the best known case of this involved the discoveries of [[Ignaz Semmelweis]] in 19th century [[Vienna]], which led to the [[germ theory of disease]]. | Sometimes, however, scientists have refused to examine new evidence which could undermine confidence in an established theory. Possibly the best known case of this involved the discoveries of [[Ignaz Semmelweis]] in 19th century [[Vienna]], which led to the [[germ theory of disease]]. |