Louis Pasteur is well-known for saving lives by pioneering pasteurization and researching bacteria. He's less well-known for collecting a large sum of prize money for a contest that ended in an epic battle of scientific theists.
Louis Pasteur's swan-necked flask, above.
Well into the 1800s, people thought that, under the right conditions, life could be spontaneously generated from nonliving material. They saw that meat left in the sun was soon full of maggots, and that stagnant water was soon full of mosquitoes. It stood to reason. Over the years some spontaneous generation issues were explained, but others remained outstanding. In the 1800s, the idea that life just happens under certain conditions, the way water droplets just form when a cold drink is left outside on a warm day, became an argument for atheism. Life was a physical phenomenon like anything else.
Louis Pasteur set up an experiment to disprove that nonsense. He had three reasons for devoting his time to the project. First, he had some very good ideas as to where this supposed spontaneous life really came from. Secondly, the Academy of Science was offering a hefty prize to the first person to disprove the best current research, done by a man named Pouchet, on spontaneous generation of life. Thirdly, Pasteur was a shrewd scientists and knew that stressing theism would endear him to people with money who could fund his research.
He looked at Felix Pouchet's work. Pouchet was an advocate of heterogenesis, a theory that held that life could only spring from certain types of organic matter in certain combinations. Pouchet had carefully sterilized broth, and put it in sterilized beakers. Despite his precautions, which were more well-thought-out and stringent than any others at the time, the water was soon filled with microorganisms. The broth, derived from life, and the air, necessary to life, had combined to create spontaneous life, Pouchet claimed.
Pasteur disagreed. He designed better bottles, which would allow air to leak in and circulate over the broth, but did not allow dust from the atmosphere to settle into the broth. Months later, his broth remained clear and sterile. Either life was generated without the benefit or organic matter or Pouchet's spontaneously-generated life had actually been contaminating bacteria which had rode in on the dust. Either way, Pouchet was wrong.
Pasteur became the celebrated darling of theists, and went on to do well-funded, important, and indeed life-saving work. There was just one problem. Pouchet was advocating theism just as much as Pasteur had been. Pouchet's whole experiment was meant to show that only decayed life could make life because it took an initial "divine spark" to make life happen. Pouchet also believed that divine intervention was required to keep life going, which is why only certain types of organic matter allowed life to spontaneously generate. Pouchet's theories, though, were lost in the clamor to support Pasteur's work which seemed to disprove the ideas of those awful atheists. Pouchet, essentially, was labelled atheist for not being the right kind of theist.
As Pouchet's conclusions were wrong, not much was lost to the scientific community because of the disparagement of his work. Still, the incident shows how the subtle points of a particular experiment can be lost when people perceive it to be part of a body of research they don't like.
[Via Scientific Feuds.]