It seems that the burden of proof in popular argumentation is shifted to whatever favorable point we’d like to make. And believe me, people of all sides are prone to doing it. But think about some issue that causes controversy for whatever reason – climate change, eating GMO foods, vaccines and autism, and so on. I think the very best that science is going to be able to do is rely on the default position that Marauding Ghoulies do NOT cause cancer. If we insist on a burden of proof that requires me to prove that Marauding Ghoulies do NOT cause cancer, which is just about impossible to demonstrate, we are requiring unicorns to make appearances. It is simply not possible to demonstrate proof against an unfalsifiable claim. In this case, we are truly going to have to come up with standards that first categorize claims into those that are and those that are not falsifiable and second, when we stumble upon the latter type of claim, agree that the best we are going to be able to do is examine the existence or lack of existence of relative risks and rely upon the large body of research on such particular claims to be able to establish whether in fact Marauding Ghoulies are good candidates for cancer causing creatures.
We will demonstrate with specifics should I find my way to a keyboard someday soon.