evidence: It was Louis Pasteur who convinced a skeptical medical community that contagious germs cause disease; his "germ theory" now serves as the official explanation for most illness. However, in his private diaries he states unequivocally that in his entire career he was not once able to transfer disease with a pure culture of bacteria (he obviously wasn’t able to purify viruses at that time). He admitted that the whole effort to prove contagion was a failure, leading to his famous death bed confession that "the germ is nothing, the terrain is everything." [...] >> At the core of this debate, I think many people pose terrain theory vs. germ theory in simplistically binary way - it's worse than "nature vs. nurture"! The need for suitable soil and water to grow a garden does not disprove the role of seeds - and vice versa - the importance of a healthy human immune system does not disprove the importance (or existence) of germs or viruses, or vice-versa. <<