For years, everyone "knew" that stomach ulcers were caused by stress. I can remember my parents talking about family members with ulcer problems and trying to figure out what it was about their personalities and habits and life circumstances that were causing them.
Then, in 1982, two Australian physicians announced their discovery that these ulcers were caused by a particular bacterium, and could be cured in most cases by a simple course of antibiotics. But Barry Marshall and Robin Warren had a difficult time getting anyone to listen. But eventually they did, and today they were awarded the Nobel Prize for Medicine.
Nobel Prizes in the sciences are often awarded long after a particular discovery or breakthrough due to the time required to see if the new idea really works. But that was not Marshall's and Warren's problem. They could show people right away that their discovery worked, they just couldn't get them to "see" that it worked since everyone "knew" what caused ulcers:
"This was very much against prevailing knowledge and dogma because it was thought that peptic ulcer disease was the result of stress and lifestyle," Staffan Normark, a member of the Nobel Assembly at the Karolinska institute, said at a news conference.
The Australians' proposal of a microbial cause instead was "very controversial and unexpected," said Goran Hansson, who chairs the Nobel committee that awards the medicine or physiology prize. "They had to spend the first few years convincing the rest of the world."
Marshall even deliberately infected himself with the bacterium in 1985 and showed that it caused stomach illness, noted Lord May of Oxford, president of Britain's Royal Society. Marshall suffered inflammation, which can lead to an ulcer.
I am always glad for "hey, wait a minute" thinkers like Marshall and Warren. Far too often we settle on an explanation for something that doesn't account for all of the relevant facts. I think we are especially likely to do this when there is a moral or ideological element to the question. With ulcers, everyone believed they were caused by the sufferer's poor eating habits or nervousness, which is another way of saying that the ulcers were his or her fault. So the Australians' were really addressing not only the mechanics of ulcers but the broader "moral" framework that had grown up around them, the "dogma" as the Nobel Spokesperson said above.