I know I remember seeing a documentary about all this and how surgeons who frequently did autopsies at that time would often cut themselves, develop a fever and die from septic shock, never having learned that they maybe should wash their hands after playing with dead tissue. Germ theory wasn't even a theory then, because people didn't have any idea there could be such a thing as germs.
It makes me wonder what would people in the Renaissance or middle ages say, if we were to travel back in time and talk about dinosaurs. I'm sure they'd lock us up as mentally ill. How could there ever have been such a thing as gigantic mega-lizards walking around on earth!
From the micro to the macroscopic it's funny how we humans always have to learn things very slowly and only after making many incorrect assumptions.